List(Of T).InsertRange Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Inserts the elements of a collection into the List(Of T) at the specified index.
Assembly: mscorlib (in mscorlib.dll)
'Declaration Public Sub InsertRange ( _ index As Integer, _ collection As IEnumerable(Of T) _ )
Parameters
- index
- Type: System.Int32
The zero-based index at which the new elements should be inserted.
- collection
- Type: System.Collections.Generic.IEnumerable(Of T)
The collection whose elements should be inserted into the List(Of T). The collection itself cannot be Nothing, but it can contain elements that are Nothing, if type T is a reference type.
| Exception | Condition |
|---|---|
| ArgumentNullException | collection is Nothing. |
| ArgumentOutOfRangeException | index is less than 0. -or- index is greater than Count. |
List(Of T) accepts Nothing as a valid value for reference types and allows duplicate elements.
If the new Count (the current Count plus the size of the collection) will be greater than Capacity, the capacity of the List(Of T) is increased by automatically reallocating the internal array to accommodate the new elements, and the existing elements are copied to the new array before the new elements are added.
If index is equal to Count, the elements are added to the end of List(Of T).
The order of the elements in the collection is preserved in the List(Of T).
This method is an O(n + m) operation, where n is the number of elements to be added and m is Count.
The following code example demonstrates InsertRange method and various other methods of the List(Of T) class that act on ranges. After the list has been created and populated with the names of several peaceful plant-eating dinosaurs, the InsertRange method is used to insert an array of three ferocious meat-eating dinosaurs into the list, beginning at index location 3.
Imports System.Collections.Generic Public Class Example Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock) Dim input() As String = {"Brachiosaurus", _ "Amargasaurus", _ "Mamenchisaurus"} Dim dinosaurs As New List(Of String)(input) outputBlock.Text += String.Format(vbLf & "Capacity: {0}", dinosaurs.Capacity) & vbCrLf outputBlock.Text &= vbCrLf For Each dinosaur As String In dinosaurs outputBlock.Text &= dinosaur & vbCrLf Next outputBlock.Text &= vbLf & "AddRange(dinosaurs)" & vbCrLf dinosaurs.AddRange(dinosaurs) outputBlock.Text &= vbCrLf For Each dinosaur As String In dinosaurs outputBlock.Text &= dinosaur & vbCrLf Next outputBlock.Text += String.Format(vbLf & "RemoveRange(2, 2)") & vbCrLf dinosaurs.RemoveRange(2, 2) outputBlock.Text &= vbCrLf For Each dinosaur As String In dinosaurs outputBlock.Text &= dinosaur & vbCrLf Next input = New String() {"Tyrannosaurus", _ "Deinonychus", _ "Velociraptor"} outputBlock.Text += String.Format(vbLf & "InsertRange(3, input)") & vbCrLf dinosaurs.InsertRange(3, input) outputBlock.Text &= vbCrLf For Each dinosaur As String In dinosaurs outputBlock.Text &= dinosaur & vbCrLf Next outputBlock.Text += String.Format(vbLf & "output = dinosaurs.GetRange(2, 3).ToArray") & vbCrLf Dim output() As String = dinosaurs.GetRange(2, 3).ToArray() outputBlock.Text &= vbCrLf For Each dinosaur As String In output outputBlock.Text &= dinosaur & vbCrLf Next End Sub End Class ' This code example produces the following output: ' 'Capacity: 3 ' 'Brachiosaurus 'Amargasaurus 'Mamenchisaurus ' 'AddRange(dinosaurs) ' 'Brachiosaurus 'Amargasaurus 'Mamenchisaurus 'Brachiosaurus 'Amargasaurus 'Mamenchisaurus ' 'RemoveRange(2, 2) ' 'Brachiosaurus 'Amargasaurus 'Amargasaurus 'Mamenchisaurus ' 'InsertRange(3, input) ' 'Brachiosaurus 'Amargasaurus 'Amargasaurus 'Tyrannosaurus 'Deinonychus 'Velociraptor 'Mamenchisaurus ' 'output = dinosaurs.GetRange(2, 3).ToArray ' 'Amargasaurus 'Tyrannosaurus 'Deinonychus