ControlDesigner.OnClick(DesignerRegionMouseEventArgs) Method

Reference

Definition

Namespace:: System.Web.UI.Design

Assembly:: System.Design.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Called by the design host when the user clicks the associated control at design time.

protected:
 virtual void OnClick(System::Web::UI::Design::DesignerRegionMouseEventArgs ^ e);

protected virtual void OnClick (System.Web.UI.Design.DesignerRegionMouseEventArgs e);

abstract member OnClick : System.Web.UI.Design.DesignerRegionMouseEventArgs -> unit
override this.OnClick : System.Web.UI.Design.DesignerRegionMouseEventArgs -> unit

Protected Overridable Sub OnClick (e As DesignerRegionMouseEventArgs)

Parameters

e: DesignerRegionMouseEventArgs

A DesignerRegionMouseEventArgs object that specifies the location and, possibly, the control designer region that the user clicked.

Examples

The following code example shows how to use a handler for the OnClick event in a clickable region of the control and use a DesignerRegionMouseEventArgs object to identify the region that is being clicked.

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

// 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();
    }
}

' 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

Remarks

The ViewEvent event is raised by the design host for certain actions on a control in the design surface. For example, an event is raised for the following conditions:

The user clicks the control.
The control designer paints on the design surface.
The user enters or exits template editing mode for the control.

The ControlDesigner class supplies a default delegate to handle the IControlDesignerView.ViewEvent event. Classes deriving from ControlDesigner override the OnClick method to process events that are raised when the user clicks a control.

The OnClick method allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

The default implementation of the OnClick method returns without performing any processing.

Notes to Inheritors

Override the OnClick(DesignerRegionMouseEventArgs) method in a class deriving from the ControlDesigner class to handle design-time click events on the control. If e is not null, the clicked region, if any, is specified in the Region property.

Applies to