.NET Framework Class Library
ControlDesignerUpdateDesignTimeHtml Method

Refreshes the design-time HTML markup for the associated Web server control by calling the GetDesignTimeHtml method.

Namespace:   System.Web.UI.Design
Assembly:  System.Design (in System.Design.dll)
Syntax
Public Overridable Sub UpdateDesignTimeHtml
public virtual void UpdateDesignTimeHtml()
public:
virtual void UpdateDesignTimeHtml()
abstract UpdateDesignTimeHtml : unit -> unit  
override UpdateDesignTimeHtml : unit -> unit
Remarks

The UpdateDesignTimeHtml method is called by the design host to update the display of the associated Web server control at design time, such as when the control has been modified. Also, a control designer can call the UpdateDesignTimeHtml method after modifying values of the control to update the display of the control.

NoteNote

If you are calling the ComponentChanged event, or using the PropertyDescriptor object to set properties, the IComponentChangeService interface calls the UpdateDesignTimeHtml method for you.

Examples

The following code example demonstrates how to respond to a Click event in a control designer to change the focus between regions in a multi-region control and use the UpdateDesignTimeHtml method to update the appearance of the control in the design host.

This code example is part of a larger example for the EditableDesignerRegion class.

' Handler for the Click event, which provides the region in the arguments. 
Protected Overrides Sub OnClick(ByVal e As DesignerRegionMouseEventArgs)
    If IsNothing(e.Region) Then 
        Return 
    End If 

    ' If the clicked region is not a header, return 
    If e.Region.Name.IndexOf("Header") <> 0 Then 
        Return 
    End If 

    ' Switch the current view if required 
    If e.Region.Name.Substring(6, 1) <> myControl.CurrentView.ToString() Then
        myControl.CurrentView = Integer.Parse(e.Region.Name.Substring(6, 1))
        MyBase.UpdateDesignTimeHtml()
    End If 
End Sub
// Handler for the Click event, which provides the region in the arguments. 
protected override void OnClick(DesignerRegionMouseEventArgs e)
{
    if (e.Region == null)
        return;

    // If the clicked region is not a header, return 
    if (e.Region.Name.IndexOf("Header") != 0)
        return;

    // Switch the current view if required 
    if (e.Region.Name.Substring(6, 1) != myControl.CurrentView.ToString())
    {
        myControl.CurrentView = int.Parse(e.Region.Name.Substring(6, 1));
        base.UpdateDesignTimeHtml();
    }
}
Version Information

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0
.NET Framework Security
Platforms

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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