ControlDesigner.GetEmptyDesignTimeHtml Method
Definition
Retrieves the HTML markup to represent a Web server control at design time that will have no visual representation at run time.
protected:
virtual System::String ^ GetEmptyDesignTimeHtml();
protected virtual string GetEmptyDesignTimeHtml ();
abstract member GetEmptyDesignTimeHtml : unit -> string
override this.GetEmptyDesignTimeHtml : unit -> string
Protected Overridable Function GetEmptyDesignTimeHtml () As String
Returns
The HTML markup used to represent a control at design time that would otherwise have no visual representation. The default is a rectangle that contains the type and ID of the component.
Examples
The following code example demonstrates how to override the GetDesignTimeHtml method in a custom control designer. If the Text
property for the associated control is empty, the GetDesignTimeHtml method calls GetEmptyDesignTimeHtml method. Otherwise, the GetDesignTimeHtml method creates and renders a Hyperlink
control.
public override string GetDesignTimeHtml()
{
if (simpleControl.Text.Length > 0)
{
string spec = "<a href='{0}.aspx'>{0}</a>";
return String.Format(spec, simpleControl.Text);
}
else
{
return GetEmptyDesignTimeHtml();
}
}
Public Overrides Function GetDesignTimeHtml() As String
' Component is the instance of the component or control that
' this designer object is associated with. This property is
' inherited from System.ComponentModel.ComponentDesigner.
simpleControl = CType(Component, Simple)
If simpleControl.Text.Length > 0 Then
Dim sw As New StringWriter()
Dim tw As New HtmlTextWriter(sw)
Dim placeholderLink As New HyperLink()
' Put simpleControl.Text into the link's Text.
placeholderLink.Text = simpleControl.Text
placeholderLink.NavigateUrl = simpleControl.Text
placeholderLink.RenderControl(tw)
Return sw.ToString()
Else
Return GetEmptyDesignTimeHtml()
End If
End Function
Remarks
The default behavior of the GetEmptyDesignTimeHtml method is to return a string that contains the name of the component. The GetEmptyDesignTimeHtml method should be called in the implementation of the GetDesignTimeHtml method when there is no design-time HTML markup.