ControlCollection.Add Method (System.Web.UI)

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.NET Framework Class Library

ControlCollection.Add Method

Adds the specified Control object to the collection.

Namespace: System.Web.UI
Assembly: System.Web (in System.Web.dll)

Syntax

Visual Basic

Public Overridable Sub Add ( _
	child As Control _
)

public virtual void Add(
	Control child
)

Visual C++

public:
virtual void Add(
	Control^ child
)

abstract Add : 
        child:Control -> unit 
override Add : 
        child:Control -> unit

Parameters

child: Type: System.Web.UI.Control
The Control to add to the collection.

Exceptions

Exception	Condition
ArgumentNullException	Thrown if the child parameter does not specify a control.
HttpException	Thrown if the ControlCollection is read-only.

Remarks

The new control is added to the end of an ordinal index array. The control can be an instance of any ASP.NET server control, a custom server control you create, or a literal control.

To add a control to the collection at a specific index location, use the AddAt method.

Examples

The following code example uses the Add method to add a series of template items, the number of which are taken from the server control's view state, to a custom templated control.

Visual Basic


' Override to create repeated items.
Protected Overrides Sub CreateChildControls()
    Dim O As Object = ViewState("NumItems")
    If Not (O Is Nothing)
       ' Clear any existing child controls.
       Controls.Clear()

       Dim I As Integer
       Dim NumItems As Integer = CInt(O)
       For I = 0 To NumItems - 1
          ' Create an item.
          Dim Item As RepeaterItemVB = New RepeaterItemVB(I, Nothing)
          ' Initialize the item from the template.
          ItemTemplate.InstantiateIn(Item)
          ' Add the item to the ControlCollection.
          Controls.Add(Item)
       Next
    End If
End Sub


// Override to create repeated items.
protected override void CreateChildControls() {
    object o = ViewState["NumItems"];
    if (o != null) {
       // Clear any existing child controls.
       Controls.Clear();

       int numItems = (int)o;
       for (int i=0; i < numItems; i++) {
          // Create an item.
          RepeaterItem item = new RepeaterItem(i, null);
          // Initialize the item from the template.
          ItemTemplate.InstantiateIn(item);
          // Add the item to the ControlCollection.
          Controls.Add(item);
       }
    }
}

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

Reference

ControlCollection Class

System.Web.UI Namespace

Controls

AddAt