List(Of T).AddRange Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Adds the elements of the specified collection to the end of the List(Of T).
Assembly: mscorlib (in mscorlib.dll)
Parameters
- collection
- Type: System.Collections.Generic.IEnumerable(Of T)
The collection whose elements should be added to the end of 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. |
The order of the elements in the collection is preserved in the List(Of T).
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 the List(Of T) can accommodate the new elements without increasing the Capacity, this method is an O(n) operation, where n is the number of elements to be added. If the capacity needs to be increased to accommodate the new elements, this method becomes an O(n + m) operation, where n is the number of elements to be added and m is Count.
The following code example demonstrates the AddRange method and various other methods of the List(Of T) class that act on ranges. An array of strings is created and passed to the constructor, populating the list with the elements of the array. The AddRange method is called, with the list as its argument. The result is that the current elements of the list are added to the end of the list, duplicating all the elements.
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