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Queryable.All(TSource) Method

Determines whether all the elements of a sequence satisfy a condition.

Namespace:  System.Linq
Assembly:  System.Core (in System.Core.dll)

static member All : 
        source:IQueryable<'TSource> * 
        predicate:Expression<Func<'TSource, bool>> -> bool

Type Parameters

TSource

The type of the elements of source.

Parameters

source
Type: System.Linq.IQueryable(TSource)

A sequence whose elements to test for a condition.

predicate
Type: System.Linq.Expressions.Expression(Func(TSource, Boolean))

A function to test each element for a condition.

Return Value

Type: System.Boolean
true if every element of the source sequence passes the test in the specified predicate, or if the sequence is empty; otherwise, false.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IQueryable(TSource). When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

ExceptionCondition
ArgumentNullException

source or predicate is a null reference (Nothing in Visual Basic).

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 All(TSource)(IQueryable(TSource), Expression(Func(TSource, Boolean))) method generates a MethodCallExpression that represents calling All(TSource)(IQueryable(TSource), Expression(Func(TSource, Boolean))) 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.

The query behavior that occurs as a result of executing an expression tree that represents calling All(TSource)(IQueryable(TSource), Expression(Func(TSource, Boolean))) depends on the implementation of the source parameter's type. The expected behavior is that it determines if all the elements in source satisfy the condition in predicate.

The following code example demonstrates how to use All(TSource)(IQueryable(TSource), Expression(Func(TSource, Boolean))) to determine whether all the elements in a sequence satisfy a condition.

No code example is currently available or this language may not be supported.

The Boolean value that the All(TSource)(IQueryable(TSource), Expression(Func(TSource, Boolean))) method returns is typically used in the predicate of a where clause (Where clause in Visual Basic) or a direct call to the Where method. The following example demonstrates this use of the All method.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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