HasControls Method
.NET Framework Class Library
Control..::.HasControls Method

Determines if the server control contains any child controls.

Namespace:  System.Web.UI
Assembly:  System.Web (in System.Web.dll)
Visual Basic (Declaration)
Public Overridable Function HasControls As Boolean
Visual Basic (Usage)
Dim instance As Control
Dim returnValue As Boolean

returnValue = instance.HasControls()
C#
public virtual bool HasControls()
Visual C++
public:
virtual bool HasControls()
JScript
public function HasControls() : boolean

Return Value

Type: System..::.Boolean
true if the control contains other controls; otherwise, false.

Since this method simply determines if any child controls exist, it can enhance performance by allowing you to avoid an unnecessary Count property call. Calls to this property require a ControlCollection object to be instantiated. If there are no children, this object creation wastes server resources.

Notes to Inheritors:

The HasControls method should be overridden only to change metadata attributes such as EditorBrowsableAttribute. For more information about using attributes, see Extending Metadata Using Attributes.

The following example uses the HasControls method to determine if any controls exist before using the Count property to iterate through a ControlCollection object.

Visual Basic
If HasControls() Then
    Dim i As Integer
    For i = 0 To Controls.Count - 1
        Controls(i).RenderControl(writer)
    Next i
End If
C#
if (HasControls()) {
                 for (int i=0; i < Controls.Count; i++) {
                     Controls[i].RenderControl(writer);
                 }
   }
JScript
if (HasControls()) {
                 for (var i : int = 0; i < Controls.Count; i++) {
                     Controls[i].RenderControl(writer);
                 }
   }

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

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