StringCollection Class
Represents a collection of strings.
System.Collections.Specialized.StringCollection
System.Configuration.CommaDelimitedStringCollection
Assembly: System (in System.dll)
The StringCollection type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | Count | Gets the number of strings contained in the StringCollection. |
![]() | IsReadOnly | Gets a value indicating whether the StringCollection is read-only. |
![]() | IsSynchronized | Gets a value indicating whether access to the StringCollection is synchronized (thread safe). |
![]() | Item | Gets or sets the element at the specified index. |
![]() | SyncRoot | Gets an object that can be used to synchronize access to the StringCollection. |
| Name | Description | |
|---|---|---|
![]() | Add | Adds a string to the end of the StringCollection. |
![]() | AddRange | Copies the elements of a string array to the end of the StringCollection. |
![]() | Clear | Removes all the strings from the StringCollection. |
![]() | Contains | Determines whether the specified string is in the StringCollection. |
![]() | CopyTo | Copies the entire StringCollection values to a one-dimensional array of strings, starting at the specified index of the target array. |
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetEnumerator | Returns a StringEnumerator that iterates through the StringCollection. |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | IndexOf | Searches for the specified string and returns the zero-based index of the first occurrence within the StringCollection. |
![]() | Insert | Inserts a string into the StringCollection at the specified index. |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | Remove | Removes the first occurrence of a specific string from the StringCollection. |
![]() | RemoveAt | Removes the string at the specified index of the StringCollection. |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() | AsParallel | Enables parallelization of a query. (Defined by ParallelEnumerable.) |
![]() | AsQueryable | Converts an IEnumerable to an IQueryable. (Defined by Queryable.) |
![]() | Cast<TResult> | Casts the elements of an IEnumerable to the specified type. (Defined by Enumerable.) |
![]() | OfType<TResult> | Filters the elements of an IEnumerable based on a specified type. (Defined by Enumerable.) |
| Name | Description | |
|---|---|---|
![]() ![]() | ICollection.CopyTo | Copies the entire StringCollection to a compatible one-dimensional Array, starting at the specified index of the target array. |
![]() ![]() | IEnumerable.GetEnumerator | Returns a IEnumerator that iterates through the StringCollection. |
![]() ![]() | IList.Add | Adds an object to the end of the StringCollection. |
![]() ![]() | IList.Contains | Determines whether an element is in the StringCollection. |
![]() ![]() | IList.IndexOf | Searches for the specified Object and returns the zero-based index of the first occurrence within the entire StringCollection. |
![]() ![]() | IList.Insert | Inserts an element into the StringCollection at the specified index. |
![]() ![]() | IList.IsFixedSize | Gets a value indicating whether the StringCollection object has a fixed size. |
![]() ![]() | IList.IsReadOnly | Gets a value indicating whether the StringCollection object is read-only. |
![]() ![]() | IList.Item | Gets or sets the element at the specified index. |
![]() ![]() | IList.Remove | Removes the first occurrence of a specific object from the StringCollection. |
The following code example demonstrates several of the properties and methods of StringCollection.
using System; using System.Collections; using System.Collections.Specialized; public class SamplesStringCollection { public static void Main() { // Create and initializes a new StringCollection. StringCollection myCol = new StringCollection(); // Add a range of elements from an array to the end of the StringCollection. String[] myArr = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" }; myCol.AddRange( myArr ); // Display the contents of the collection using foreach. This is the preferred method. Console.WriteLine( "Displays the elements using foreach:" ); PrintValues1( myCol ); // Display the contents of the collection using the enumerator. Console.WriteLine( "Displays the elements using the IEnumerator:" ); PrintValues2( myCol ); // Display the contents of the collection using the Count and Item properties. Console.WriteLine( "Displays the elements using the Count and Item properties:" ); PrintValues3( myCol ); // Add one element to the end of the StringCollection and insert another at index 3. myCol.Add( "* white" ); myCol.Insert( 3, "* gray" ); Console.WriteLine( "After adding \"* white\" to the end and inserting \"* gray\" at index 3:" ); PrintValues1( myCol ); // Remove one element from the StringCollection. myCol.Remove( "yellow" ); Console.WriteLine( "After removing \"yellow\":" ); PrintValues1( myCol ); // Remove all occurrences of a value from the StringCollection. int i = myCol.IndexOf( "RED" ); while ( i > -1 ) { myCol.RemoveAt( i ); i = myCol.IndexOf( "RED" ); } // Verify that all occurrences of "RED" are gone. if ( myCol.Contains( "RED" ) ) Console.WriteLine( "*** The collection still contains \"RED\"." ); Console.WriteLine( "After removing all occurrences of \"RED\":" ); PrintValues1( myCol ); // Copy the collection to a new array starting at index 0. String[] myArr2 = new String[myCol.Count]; myCol.CopyTo( myArr2, 0 ); Console.WriteLine( "The new array contains:" ); for ( i = 0; i < myArr2.Length; i++ ) { Console.WriteLine( " [{0}] {1}", i, myArr2[i] ); } Console.WriteLine(); // Clears the entire collection. myCol.Clear(); Console.WriteLine( "After clearing the collection:" ); PrintValues1( myCol ); } // Uses the foreach statement which hides the complexity of the enumerator. // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection. public static void PrintValues1( StringCollection myCol ) { foreach ( Object obj in myCol ) Console.WriteLine( " {0}", obj ); Console.WriteLine(); } // Uses the enumerator. // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection. public static void PrintValues2( StringCollection myCol ) { StringEnumerator myEnumerator = myCol.GetEnumerator(); while ( myEnumerator.MoveNext() ) Console.WriteLine( " {0}", myEnumerator.Current ); Console.WriteLine(); } // Uses the Count and Item properties. public static void PrintValues3( StringCollection myCol ) { for ( int i = 0; i < myCol.Count; i++ ) Console.WriteLine( " {0}", myCol[i] ); Console.WriteLine(); } } /* This code produces the following output. Displays the elements using foreach: RED orange yellow RED green blue RED indigo violet RED Displays the elements using the IEnumerator: RED orange yellow RED green blue RED indigo violet RED Displays the elements using the Count and Item properties: RED orange yellow RED green blue RED indigo violet RED After adding "* white" to the end and inserting "* gray" at index 3: RED orange yellow * gray RED green blue RED indigo violet RED * white After removing "yellow": RED orange * gray RED green blue RED indigo violet RED * white After removing all occurrences of "RED": orange * gray green blue indigo violet * white The new array contains: [0] orange [1] * gray [2] green [3] blue [4] indigo [5] violet [6] * white After clearing the collection: */
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, 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.
Public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
This implementation does not provide a synchronized (thread safe) wrapper for a StringCollection, but derived classes can create their own synchronized versions of the StringCollection using the SyncRoot property.
Enumerating through a collection is intrinsically not a thread safe procedure. Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

