BlockingCollection<T> Class

Provides blocking and bounding capabilities for thread-safe collections that implement IProducerConsumerCollection<T>.

System.Object
  System.Collections.Concurrent.BlockingCollection<T>

Namespace:  System.Collections.Concurrent
Assembly:  System (in System.dll)

[ComVisibleAttribute(false)]
[HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization = true, 
	ExternalThreading = true)]
public class BlockingCollection<T> : IEnumerable<T>, 
	ICollection, IEnumerable, IDisposable

Type Parameters

T

The type of elements in the collection.

The BlockingCollection<T> type exposes the following members.

  NameDescription
Public methodBlockingCollection<T>()Initializes a new instance of the BlockingCollection<T> class without an upper-bound.
Public methodBlockingCollection<T>(Int32)Initializes a new instance of the BlockingCollection<T> class with the specified upper-bound.
Public methodBlockingCollection<T>(IProducerConsumerCollection<T>)Initializes a new instance of the BlockingCollection<T> class without an upper-bound and using the provided IProducerConsumerCollection<T> as its underlying data store.
Public methodBlockingCollection<T>(IProducerConsumerCollection<T>, Int32)Initializes a new instance of the BlockingCollection<T> class with the specified upper-bound and using the provided IProducerConsumerCollection<T> as its underlying data store.
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  NameDescription
Public propertyBoundedCapacityGets the bounded capacity of this BlockingCollection<T> instance.
Public propertyCountGets the number of items contained in the BlockingCollection<T>.
Public propertyIsAddingCompletedGets whether this BlockingCollection<T> has been marked as complete for adding.
Public propertyIsCompletedGets whether this BlockingCollection<T> has been marked as complete for adding and is empty.
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  NameDescription
Public methodAdd(T)Adds the item to the BlockingCollection<T>.
Public methodAdd(T, CancellationToken)Adds the item to the BlockingCollection<T>.
Public methodStatic memberAddToAny(BlockingCollection<T>[], T)Adds the specified item to any one of the specified BlockingCollection<T> instances.
Public methodStatic memberAddToAny(BlockingCollection<T>[], T, CancellationToken)Adds the specified item to any one of the specified BlockingCollection<T> instances.
Public methodCompleteAddingMarks the BlockingCollection<T> instances as not accepting any more additions.
Public methodCopyToCopies all of the items in the BlockingCollection<T> instance to a compatible one-dimensional array, starting at the specified index of the target array.
Public methodDispose()Releases all resources used by the current instance of the BlockingCollection<T> class.
Protected methodDispose(Boolean)Releases resources used by the BlockingCollection<T> instance.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetConsumingEnumerable()Provides a consuming IEnumerable for items in the collection.
Public methodGetConsumingEnumerable(CancellationToken)Provides a consuming IEnumerable for items in the collection.
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodTake()Removes an item from the BlockingCollection<T>.
Public methodTake(CancellationToken)Removes an item from the BlockingCollection<T>.
Public methodStatic memberTakeFromAny(BlockingCollection<T>[], T)Takes an item from any one of the specified BlockingCollection<T> instances.
Public methodStatic memberTakeFromAny(BlockingCollection<T>[], T, CancellationToken)Takes an item from any one of the specified BlockingCollection<T> instances while observing the specified cancellation token.
Public methodToArrayCopies the items from the BlockingCollection<T> instance into a new array.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodTryAdd(T)Tries to add the specified item to the BlockingCollection<T>.
Public methodTryAdd(T, Int32)Tries to add the specified item to the BlockingCollection<T> within the specified time period.
Public methodTryAdd(T, TimeSpan)Tries to add the specified item to the BlockingCollection<T>.
Public methodTryAdd(T, Int32, CancellationToken)Tries to add the specified item to the BlockingCollection<T> within the specified time period, while observing a cancellation token.
Public methodStatic memberTryAddToAny(BlockingCollection<T>[], T)Tries to add the specified item to any one of the specified BlockingCollection<T> instances.
Public methodStatic memberTryAddToAny(BlockingCollection<T>[], T, Int32)Tries to add the specified item to any one of the specified BlockingCollection<T> instances.
Public methodStatic memberTryAddToAny(BlockingCollection<T>[], T, TimeSpan)Tries to add the specified item to any one of the specified BlockingCollection<T> instances while observing the specified cancellation token.
Public methodStatic memberTryAddToAny(BlockingCollection<T>[], T, Int32, CancellationToken)Tries to add the specified item to any one of the specified BlockingCollection<T> instances.
Public methodTryTake(T)Tries to remove an item from the BlockingCollection<T>.
Public methodTryTake(T, Int32)Tries to remove an item from the BlockingCollection<T> in the specified time period.
Public methodTryTake(T, TimeSpan)Tries to remove an item from the BlockingCollection<T> in the specified time period.
Public methodTryTake(T, Int32, CancellationToken)Tries to remove an item from the BlockingCollection<T> in the specified time period while observing a cancellation token.
Public methodStatic memberTryTakeFromAny(BlockingCollection<T>[], T)Tries to remove an item from any one of the specified BlockingCollection<T> instances.
Public methodStatic memberTryTakeFromAny(BlockingCollection<T>[], T, Int32)Tries to remove an item from any one of the specified BlockingCollection<T> instances.
Public methodStatic memberTryTakeFromAny(BlockingCollection<T>[], T, TimeSpan)Tries to remove an item from any one of the specified BlockingCollection<T> instances.
Public methodStatic memberTryTakeFromAny(BlockingCollection<T>[], T, Int32, CancellationToken)Tries to remove an item from any one of the specified BlockingCollection<T> instances.
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  NameDescription
Public Extension MethodAggregate<T>(Func<T, T, T>)Overloaded. Applies an accumulator function over a sequence. (Defined by Enumerable.)
Public Extension MethodAggregate<T, TAccumulate>(TAccumulate, Func<TAccumulate, T, TAccumulate>)Overloaded. Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value. (Defined by Enumerable.)
Public Extension MethodAggregate<T, TAccumulate, TResult>(TAccumulate, Func<TAccumulate, T, TAccumulate>, Func<TAccumulate, TResult>)Overloaded. Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value, and the specified function is used to select the result value. (Defined by Enumerable.)
Public Extension MethodAll<T>Determines whether all elements of a sequence satisfy a condition. (Defined by Enumerable.)
Public Extension MethodAny<T>()Overloaded. Determines whether a sequence contains any elements. (Defined by Enumerable.)
Public Extension MethodAny<T>(Func<T, Boolean>)Overloaded. Determines whether any element of a sequence satisfies a condition. (Defined by Enumerable.)
Public Extension MethodAsEnumerable<T>Returns the input typed as IEnumerable<T>. (Defined by Enumerable.)
Public Extension MethodAsParallel()Overloaded. Enables parallelization of a query. (Defined by ParallelEnumerable.)
Public Extension MethodAsParallel<T>()Overloaded. Enables parallelization of a query. (Defined by ParallelEnumerable.)
Public Extension MethodAsQueryable()Overloaded. Converts an IEnumerable to an IQueryable. (Defined by Queryable.)
Public Extension MethodAsQueryable<T>()Overloaded. Converts a generic IEnumerable<T> to a generic IQueryable<T>. (Defined by Queryable.)
Public Extension MethodAverage<T>(Func<T, Decimal>)Overloaded. Computes the average of a sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Nullable<Decimal>>)Overloaded. Computes the average of a sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Double>)Overloaded. Computes the average of a sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Nullable<Double>>)Overloaded. Computes the average of a sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Int32>)Overloaded. Computes the average of a sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Nullable<Int32>>)Overloaded. Computes the average of a sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Int64>)Overloaded. Computes the average of a sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Nullable<Int64>>)Overloaded. Computes the average of a sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Single>)Overloaded. Computes the average of a sequence of Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodAverage<T>(Func<T, Nullable<Single>>)Overloaded. Computes the average of a sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodCast<TResult>Casts the elements of an IEnumerable to the specified type. (Defined by Enumerable.)
Public Extension MethodConcat<T>Concatenates two sequences. (Defined by Enumerable.)
Public Extension MethodContains<T>(T)Overloaded. Determines whether a sequence contains a specified element by using the default equality comparer. (Defined by Enumerable.)
Public Extension MethodContains<T>(T, IEqualityComparer<T>)Overloaded. Determines whether a sequence contains a specified element by using a specified IEqualityComparer<T>. (Defined by Enumerable.)
Public Extension MethodCount<T>()Overloaded. Returns the number of elements in a sequence. (Defined by Enumerable.)
Public Extension MethodCount<T>(Func<T, Boolean>)Overloaded. Returns a number that represents how many elements in the specified sequence satisfy a condition. (Defined by Enumerable.)
Public Extension MethodDefaultIfEmpty<T>()Overloaded. Returns the elements of the specified sequence or the type parameter's default value in a singleton collection if the sequence is empty. (Defined by Enumerable.)
Public Extension MethodDefaultIfEmpty<T>(T)Overloaded. Returns the elements of the specified sequence or the specified value in a singleton collection if the sequence is empty. (Defined by Enumerable.)
Public Extension MethodDistinct<T>()Overloaded. Returns distinct elements from a sequence by using the default equality comparer to compare values. (Defined by Enumerable.)
Public Extension MethodDistinct<T>(IEqualityComparer<T>)Overloaded. Returns distinct elements from a sequence by using a specified IEqualityComparer<T> to compare values. (Defined by Enumerable.)
Public Extension MethodElementAt<T>Returns the element at a specified index in a sequence. (Defined by Enumerable.)
Public Extension MethodElementAtOrDefault<T>Returns the element at a specified index in a sequence or a default value if the index is out of range. (Defined by Enumerable.)
Public Extension MethodExcept<T>(IEnumerable<T>)Overloaded. Produces the set difference of two sequences by using the default equality comparer to compare values. (Defined by Enumerable.)
Public Extension MethodExcept<T>(IEnumerable<T>, IEqualityComparer<T>)Overloaded. Produces the set difference of two sequences by using the specified IEqualityComparer<T> to compare values. (Defined by Enumerable.)
Public Extension MethodFirst<T>()Overloaded. Returns the first element of a sequence. (Defined by Enumerable.)
Public Extension MethodFirst<T>(Func<T, Boolean>)Overloaded. Returns the first element in a sequence that satisfies a specified condition. (Defined by Enumerable.)
Public Extension MethodFirstOrDefault<T>()Overloaded. Returns the first element of a sequence, or a default value if the sequence contains no elements. (Defined by Enumerable.)
Public Extension MethodFirstOrDefault<T>(Func<T, Boolean>)Overloaded. Returns the first element of the sequence that satisfies a condition or a default value if no such element is found. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey>(Func<T, TKey>)Overloaded. Groups the elements of a sequence according to a specified key selector function. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>)Overloaded. Groups the elements of a sequence according to a specified key selector function and compares the keys by using a specified comparer. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>)Overloaded. Groups the elements of a sequence according to a specified key selector function and projects the elements for each group by using a specified function. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey, TResult>(Func<T, TKey>, Func<TKey, IEnumerable<T>, TResult>)Overloaded. Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>)Overloaded. Groups the elements of a sequence according to a key selector function. The keys are compared by using a comparer and each group's elements are projected by using a specified function. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey, TResult>(Func<T, TKey>, Func<TKey, IEnumerable<T>, TResult>, IEqualityComparer<TKey>)Overloaded. Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. The keys are compared by using a specified comparer. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey, TElement, TResult>(Func<T, TKey>, Func<T, TElement>, Func<TKey, IEnumerable<TElement>, TResult>)Overloaded. Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. The elements of each group are projected by using a specified function. (Defined by Enumerable.)
Public Extension MethodGroupBy<T, TKey, TElement, TResult>(Func<T, TKey>, Func<T, TElement>, Func<TKey, IEnumerable<TElement>, TResult>, IEqualityComparer<TKey>)Overloaded. Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. Key values are compared by using a specified comparer, and the elements of each group are projected by using a specified function. (Defined by Enumerable.)
Public Extension MethodGroupJoin<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, IEnumerable<TInner>, TResult>)Overloaded. Correlates the elements of two sequences based on equality of keys and groups the results. The default equality comparer is used to compare keys. (Defined by Enumerable.)
Public Extension MethodGroupJoin<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, IEnumerable<TInner>, TResult>, IEqualityComparer<TKey>)Overloaded. Correlates the elements of two sequences based on key equality and groups the results. A specified IEqualityComparer<T> is used to compare keys. (Defined by Enumerable.)
Public Extension MethodIntersect<T>(IEnumerable<T>)Overloaded. Produces the set intersection of two sequences by using the default equality comparer to compare values. (Defined by Enumerable.)
Public Extension MethodIntersect<T>(IEnumerable<T>, IEqualityComparer<T>)Overloaded. Produces the set intersection of two sequences by using the specified IEqualityComparer<T> to compare values. (Defined by Enumerable.)
Public Extension MethodJoin<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, TInner, TResult>)Overloaded. Correlates the elements of two sequences based on matching keys. The default equality comparer is used to compare keys. (Defined by Enumerable.)
Public Extension MethodJoin<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, TInner, TResult>, IEqualityComparer<TKey>)Overloaded. Correlates the elements of two sequences based on matching keys. A specified IEqualityComparer<T> is used to compare keys. (Defined by Enumerable.)
Public Extension MethodLast<T>()Overloaded. Returns the last element of a sequence. (Defined by Enumerable.)
Public Extension MethodLast<T>(Func<T, Boolean>)Overloaded. Returns the last element of a sequence that satisfies a specified condition. (Defined by Enumerable.)
Public Extension MethodLastOrDefault<T>()Overloaded. Returns the last element of a sequence, or a default value if the sequence contains no elements. (Defined by Enumerable.)
Public Extension MethodLastOrDefault<T>(Func<T, Boolean>)Overloaded. Returns the last element of a sequence that satisfies a condition or a default value if no such element is found. (Defined by Enumerable.)
Public Extension MethodLongCount<T>()Overloaded. Returns an Int64 that represents the total number of elements in a sequence. (Defined by Enumerable.)
Public Extension MethodLongCount<T>(Func<T, Boolean>)Overloaded. Returns an Int64 that represents how many elements in a sequence satisfy a condition. (Defined by Enumerable.)
Public Extension MethodMax<T>()Overloaded. Returns the maximum value in a generic sequence. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Decimal>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Decimal value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Nullable<Decimal>>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Decimal value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Double>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Double value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Nullable<Double>>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Double value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Int32>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Int32 value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Nullable<Int32>>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Int32 value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Int64>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Int64 value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Nullable<Int64>>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Int64 value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Single>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Single value. (Defined by Enumerable.)
Public Extension MethodMax<T>(Func<T, Nullable<Single>>)Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Single value. (Defined by Enumerable.)
Public Extension MethodMax<T, TResult>(Func<T, TResult>)Overloaded. Invokes a transform function on each element of a generic sequence and returns the maximum resulting value. (Defined by Enumerable.)
Public Extension MethodMin<T>()Overloaded. Returns the minimum value in a generic sequence. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Decimal>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Decimal value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Nullable<Decimal>>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Decimal value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Double>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Double value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Nullable<Double>>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Double value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Int32>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Int32 value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Nullable<Int32>>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Int32 value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Int64>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Int64 value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Nullable<Int64>>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Int64 value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Single>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Single value. (Defined by Enumerable.)
Public Extension MethodMin<T>(Func<T, Nullable<Single>>)Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Single value. (Defined by Enumerable.)
Public Extension MethodMin<T, TResult>(Func<T, TResult>)Overloaded. Invokes a transform function on each element of a generic sequence and returns the minimum resulting value. (Defined by Enumerable.)
Public Extension MethodOfType<TResult>Filters the elements of an IEnumerable based on a specified type. (Defined by Enumerable.)
Public Extension MethodOrderBy<T, TKey>(Func<T, TKey>)Overloaded. Sorts the elements of a sequence in ascending order according to a key. (Defined by Enumerable.)
Public Extension MethodOrderBy<T, TKey>(Func<T, TKey>, IComparer<TKey>)Overloaded. Sorts the elements of a sequence in ascending order by using a specified comparer. (Defined by Enumerable.)
Public Extension MethodOrderByDescending<T, TKey>(Func<T, TKey>)Overloaded. Sorts the elements of a sequence in descending order according to a key. (Defined by Enumerable.)
Public Extension MethodOrderByDescending<T, TKey>(Func<T, TKey>, IComparer<TKey>)Overloaded. Sorts the elements of a sequence in descending order by using a specified comparer. (Defined by Enumerable.)
Public Extension MethodReverse<T>Inverts the order of the elements in a sequence. (Defined by Enumerable.)
Public Extension MethodSelect<T, TResult>(Func<T, TResult>)Overloaded. Projects each element of a sequence into a new form. (Defined by Enumerable.)
Public Extension MethodSelect<T, TResult>(Func<T, Int32, TResult>)Overloaded. Projects each element of a sequence into a new form by incorporating the element's index. (Defined by Enumerable.)
Public Extension MethodSelectMany<T, TResult>(Func<T, IEnumerable<TResult>>)Overloaded. Projects each element of a sequence to an IEnumerable<T> and flattens the resulting sequences into one sequence. (Defined by Enumerable.)
Public Extension MethodSelectMany<T, TResult>(Func<T, Int32, IEnumerable<TResult>>)Overloaded. Projects each element of a sequence to an IEnumerable<T>, and flattens the resulting sequences into one sequence. The index of each source element is used in the projected form of that element. (Defined by Enumerable.)
Public Extension MethodSelectMany<T, TCollection, TResult>(Func<T, Int32, IEnumerable<TCollection>>, Func<T, TCollection, TResult>)Overloaded. Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein. The index of each source element is used in the intermediate projected form of that element. (Defined by Enumerable.)
Public Extension MethodSelectMany<T, TCollection, TResult>(Func<T, IEnumerable<TCollection>>, Func<T, TCollection, TResult>)Overloaded. Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein. (Defined by Enumerable.)
Public Extension MethodSequenceEqual<T>(IEnumerable<T>)Overloaded. Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type. (Defined by Enumerable.)
Public Extension MethodSequenceEqual<T>(IEnumerable<T>, IEqualityComparer<T>)Overloaded. Determines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>. (Defined by Enumerable.)
Public Extension MethodSingle<T>()Overloaded. Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence. (Defined by Enumerable.)
Public Extension MethodSingle<T>(Func<T, Boolean>)Overloaded. Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists. (Defined by Enumerable.)
Public Extension MethodSingleOrDefault<T>()Overloaded. Returns the only element of a sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence. (Defined by Enumerable.)
Public Extension MethodSingleOrDefault<T>(Func<T, Boolean>)Overloaded. Returns the only element of a sequence that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition. (Defined by Enumerable.)
Public Extension MethodSkip<T>Bypasses a specified number of elements in a sequence and then returns the remaining elements. (Defined by Enumerable.)
Public Extension MethodSkipWhile<T>(Func<T, Boolean>)Overloaded. Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. (Defined by Enumerable.)
Public Extension MethodSkipWhile<T>(Func<T, Int32, Boolean>)Overloaded. Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. The element's index is used in the logic of the predicate function. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Decimal>)Overloaded. Computes the sum of the sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Nullable<Decimal>>)Overloaded. Computes the sum of the sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Double>)Overloaded. Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Nullable<Double>>)Overloaded. Computes the sum of the sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Int32>)Overloaded. Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Nullable<Int32>>)Overloaded. Computes the sum of the sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Int64>)Overloaded. Computes the sum of the sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Nullable<Int64>>)Overloaded. Computes the sum of the sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Single>)Overloaded. Computes the sum of the sequence of Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodSum<T>(Func<T, Nullable<Single>>)Overloaded. Computes the sum of the sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension MethodTake<T>Returns a specified number of contiguous elements from the start of a sequence. (Defined by Enumerable.)
Public Extension MethodTakeWhile<T>(Func<T, Boolean>)Overloaded. Returns elements from a sequence as long as a specified condition is true. (Defined by Enumerable.)
Public Extension MethodTakeWhile<T>(Func<T, Int32, Boolean>)Overloaded. Returns elements from a sequence as long as a specified condition is true. The element's index is used in the logic of the predicate function. (Defined by Enumerable.)
Public Extension MethodToArray<T>Creates an array from a IEnumerable<T>. (Defined by Enumerable.)
Public Extension MethodToDictionary<T, TKey>(Func<T, TKey>)Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to a specified key selector function. (Defined by Enumerable.)
Public Extension MethodToDictionary<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>)Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to a specified key selector function and key comparer. (Defined by Enumerable.)
Public Extension MethodToDictionary<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>)Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to specified key selector and element selector functions. (Defined by Enumerable.)
Public Extension MethodToDictionary<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>)Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to a specified key selector function, a comparer, and an element selector function. (Defined by Enumerable.)
Public Extension MethodToList<T>Creates a List<T> from an IEnumerable<T>. (Defined by Enumerable.)
Public Extension MethodToLookup<T, TKey>(Func<T, TKey>)Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to a specified key selector function. (Defined by Enumerable.)
Public Extension MethodToLookup<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>)Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to a specified key selector function and key comparer. (Defined by Enumerable.)
Public Extension MethodToLookup<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>)Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to specified key selector and element selector functions. (Defined by Enumerable.)
Public Extension MethodToLookup<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>)Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to a specified key selector function, a comparer and an element selector function. (Defined by Enumerable.)
Public Extension MethodUnion<T>(IEnumerable<T>)Overloaded. Produces the set union of two sequences by using the default equality comparer. (Defined by Enumerable.)
Public Extension MethodUnion<T>(IEnumerable<T>, IEqualityComparer<T>)Overloaded. Produces the set union of two sequences by using a specified IEqualityComparer<T>. (Defined by Enumerable.)
Public Extension MethodWhere<T>(Func<T, Boolean>)Overloaded. Filters a sequence of values based on a predicate. (Defined by Enumerable.)
Public Extension MethodWhere<T>(Func<T, Int32, Boolean>)Overloaded. Filters a sequence of values based on a predicate. Each element's index is used in the logic of the predicate function. (Defined by Enumerable.)
Public Extension MethodZip<T, TSecond, TResult>Applies a specified function to the corresponding elements of two sequences, producing a sequence of the results. (Defined by Enumerable.)
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  NameDescription
Explicit interface implemetationPrivate methodICollection.CopyToCopies all of the items in the BlockingCollection<T> instance to a compatible one-dimensional array, starting at the specified index of the target array.
Explicit interface implemetationPrivate propertyICollection.IsSynchronizedGets a value indicating whether access to the ICollection is synchronized.
Explicit interface implemetationPrivate propertyICollection.SyncRootGets an object that can be used to synchronize access to the ICollection. This property is not supported.
Explicit interface implemetationPrivate methodIEnumerable<T>.GetEnumeratorProvides an IEnumerator<T> for items in the collection.
Explicit interface implemetationPrivate methodIEnumerable.GetEnumeratorProvides an IEnumerator for items in the collection.
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IProducerConsumerCollection<T> represents a collection that allows for thread-safe adding and removing of data. BlockingCollection<T> is used as a wrapper for an IProducerConsumerCollection<T> instance, allowing removal attempts from the collection to block until data is available to be removed. Similarly, a BlockingCollection<T> can be created to enforce an upper-bound on the number of data elements allowed in the IProducerConsumerCollection<T>; addition attempts to the collection may then block until space is available to store the added items. In this manner, BlockingCollection<T> is similar to a traditional blocking queue data structure, except that the underlying data storage mechanism is abstracted away as an IProducerConsumerCollection<T>.

When you create a BlockingCollection<T> object, you can specify not only the bounded capacity but also the type of collection to use. For example, you could specify a ConcurrentQueue<T> object for first in, first out (FIFO) behavior, or a ConcurrentStack<T> object for last in,first out (LIFO) behavior. You can use any collection class that implements the IProducerConsumerCollection<T> interface. The default collection type for BlockingCollection<T> is ConcurrentQueue<T>.

Do not modify the underlying collection directly. Use the BlockingCollection<T> methods to add or remove elements. The BlockingCollection<T> object can become corrupted if you change the underlying collection directly.

NoteNote

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: Synchronization | ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The following example demonstrates key functionality of the BlockingCollection<T> class:


using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Concurrent;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

class BlockingCollectionDemo
{
    static void Main()
    {
        AddTakeDemo.BC_AddTakeCompleteAdding();
        TryTakeDemo.BC_TryTake();
        FromToAnyDemo.BC_FromToAny();
        ConsumingEnumerableDemo.BC_GetConsumingEnumerable();
        Console.WriteLine("Press any key to exit.");
        Console.ReadKey();
    }
}
class AddTakeDemo
{
    // Demonstrates:
    //      BlockingCollection<T>.Add()
    //      BlockingCollection<T>.Take()
    //      BlockingCollection<T>.CompleteAdding()
    public static void BC_AddTakeCompleteAdding()
    {
        using (BlockingCollection<int> bc = new BlockingCollection<int>())
        {

            // Spin up a Task to populate the BlockingCollection 
            using (Task t1 = Task.Factory.StartNew(() =>
            {
                bc.Add(1);
                bc.Add(2);
                bc.Add(3);
                bc.CompleteAdding();
            }))
            {

                // Spin up a Task to consume the BlockingCollection
                using (Task t2 = Task.Factory.StartNew(() =>
                {
                    try
                    {
                        // Consume consume the BlockingCollection
                        while (true) Console.WriteLine(bc.Take());
                    }
                    catch (InvalidOperationException)
                    {
                        // An InvalidOperationException means that Take() was called on a completed collection
                        Console.WriteLine("That's All!");
                    }
                }))

                    Task.WaitAll(t1, t2);
            }
        }
    }
}

class TryTakeDemo
{
    // Demonstrates:
    //      BlockingCollection<T>.Add()
    //      BlockingCollection<T>.CompleteAdding()
    //      BlockingCollection<T>.TryTake()
    //      BlockingCollection<T>.IsCompleted
    public static void BC_TryTake()
    {
        // Construct and fill our BlockingCollection
        using (BlockingCollection<int> bc = new BlockingCollection<int>())
        {
            int NUMITEMS = 10000;
            for (int i = 0; i < NUMITEMS; i++) bc.Add(i);
            bc.CompleteAdding();
            int outerSum = 0;

            // Delegate for consuming the BlockingCollection and adding up all items
            Action action = () =>
            {
                int localItem;
                int localSum = 0;

                while (bc.TryTake(out localItem)) localSum += localItem;
                Interlocked.Add(ref outerSum, localSum);
            };

            // Launch three parallel actions to consume the BlockingCollection
            Parallel.Invoke(action, action, action);

            Console.WriteLine("Sum[0..{0}) = {1}, should be {2}", NUMITEMS, outerSum, (NUMITEMS / 2) * (NUMITEMS - 1));
            Console.WriteLine("bc.IsCompleted = {0} (should be true)", bc.IsCompleted);
        }
    }
}

class FromToAnyDemo
{

    // Demonstrates:
    //      Bounded BlockingCollection<T>
    //      BlockingCollection<T>.TryAddToAny()
    //      BlockingCollection<T>.TryTakeFromAny()
    public static void BC_FromToAny()
    {
        BlockingCollection<int>[] bcs = new BlockingCollection<int>[2];
        bcs[0] = new BlockingCollection<int>(5); // collection bounded to 5 items
        bcs[1] = new BlockingCollection<int>(5); // collection bounded to 5 items

        // Should be able to add 10 items w/o blocking
        int numFailures = 0;
        for (int i = 0; i < 10; i++)
        {
            if (BlockingCollection<int>.TryAddToAny(bcs, i) == -1) numFailures++;
        }
        Console.WriteLine("TryAddToAny: {0} failures (should be 0)", numFailures);

        // Should be able to retrieve 10 items
        int numItems = 0;
        int item;
        while (BlockingCollection<int>.TryTakeFromAny(bcs, out item) != -1) numItems++;
        Console.WriteLine("TryTakeFromAny: retrieved {0} items (should be 10)", numItems);
    }
}

class ConsumingEnumerableDemo
{
    // Demonstrates:
    //      BlockingCollection<T>.Add()
    //      BlockingCollection<T>.CompleteAdding()
    //      BlockingCollection<T>.GetConsumingEnumerable()
    public static void BC_GetConsumingEnumerable()
    {
        using (BlockingCollection<int> bc = new BlockingCollection<int>())
        {

            // Kick off a producer task
            Task.Factory.StartNew(() =>
            {
                for (int i = 0; i < 10; i++)
                {
                    bc.Add(i);
                    Thread.Sleep(100); // sleep 100 ms between adds
                }

                // Need to do this to keep foreach below from hanging
                bc.CompleteAdding();
            });

            // Now consume the blocking collection with foreach.
            // Use bc.GetConsumingEnumerable() instead of just bc because the
            // former will block waiting for completion and the latter will
            // simply take a snapshot of the current state of the underlying collection.
            foreach (var item in bc.GetConsumingEnumerable())
            {
                Console.WriteLine(item);
            }
        }
    }
}


.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

The Dispose method is not thread-safe. All other public and protected members of BlockingCollection<T> are thread-safe and may be used concurrently from multiple threads.

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