Queryable.Take(Of TSource) Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Returns a specified number of contiguous elements from the start of a sequence.
Assembly: System.Core (in System.Core.dll)
'Declaration <ExtensionAttribute> _ Public Shared Function Take(Of TSource) ( _ source As IQueryable(Of TSource), _ count As Integer _ ) As IQueryable(Of TSource)
Type Parameters
- TSource
The type of the elements of source.
Parameters
- source
- Type: System.Linq.IQueryable(Of TSource)
The sequence to return elements from.
- count
- Type: System.Int32
The number of elements to return.
Return Value
Type: System.Linq.IQueryable(Of TSource)An IQueryable(Of T) that contains the specified number of elements from the start of source.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IQueryable(Of TSource). When you use instance method syntax to call this method, omit the first parameter.| Exception | Condition |
|---|---|
| ArgumentNullException | source is Nothing. |
The Take(Of TSource)(IQueryable(Of TSource), Int32) method generates a MethodCallExpression that represents calling Take(Of TSource)(IQueryable(Of TSource), Int32) itself as a constructed generic method. It then passes the MethodCallExpression to the CreateQuery(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 Take(Of TSource)(IQueryable(Of TSource), Int32) depends on the implementation of the type of the source parameter. The expected behavior is that it takes the first count elements from the start of source.
The following code example demonstrates how to use Take(Of TSource)(IQueryable(Of TSource), Int32) to return elements from the start of a sequence.
Dim grades() As Integer = {59, 82, 70, 56, 92, 98, 85}
' Sort the grades in descending order and take the first three.
Dim topThreeGrades = _
grades.AsQueryable().OrderByDescending(Function(grade) grade).Take(3)
Dim output As New System.Text.StringBuilder
output.AppendLine("The top three grades are:")
For Each grade As Integer In topThreeGrades
output.AppendLine(grade)
Next
' Display the output.
outputBlock.Text &= output.ToString() & vbCrLf
' This code produces the following output:
' The top three grades are:
' 98
' 92
' 85