Queryable::Aggregate<TSource, TAccumulate, TResult> Method (IQueryable<TSource>^, TAccumulate, Expression<Func<TAccumulate, TSource, TAccumulate>^>^, Expression<Func<TAccumulate, TResult>^>^)
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.
Assembly: System.Core (in System.Core.dll)
public: generic<typename TSource, typename TAccumulate, typename TResult> [ExtensionAttribute] static TResult Aggregate( IQueryable<TSource>^ source, TAccumulate seed, Expression<Func<TAccumulate, TSource, TAccumulate>^>^ func, Expression<Func<TAccumulate, TResult>^>^ selector )
A sequence to aggregate over.
The initial accumulator value.
System.Linq.Expressions::Expression<Func< , , >^>^
An accumulator function to invoke on each element.
The transformed final accumulator value.
The type of the elements of source.
The type of the accumulator value.
The type of the resulting value.
This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T, TResult> types. For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.
The MethodCallExpression that represents calling itself as a constructed generic method. It then passes the MethodCallExpression to the Execute<TResult>(Expression^) method of the IQueryProvider represented by the Provider property of the source parameter.method generates a
The query behavior that occurs as a result of executing an expression tree that represents callingdepends on the implementation of the type of the source parameter. The expected behavior is that the specified function, func, is applied to each value in the source sequence and the accumulated value is returned. The seed parameter is used as the seed value for the accumulated value, which corresponds to the first parameter in func. The final accumulated value is passed to selector to obtain the result value.
To simplify common aggregation operations, the set of standard query operators also includes two counting methods, Count<TSource> and LongCount<TSource>, and four numeric aggregation methods, namely Max<TSource>, Min<TSource>, Sum, and Average.
Available since 8
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.1
Available since 8.1