ControlDesignerGetEmptyDesignTimeHtml Method

Retrieves the HTML markup to represent a Web server control at design time that will have no visual representation at run time.

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

protected virtual string GetEmptyDesignTimeHtml()
virtual String^ GetEmptyDesignTimeHtml()
abstract GetEmptyDesignTimeHtml : unit -> string
override GetEmptyDesignTimeHtml : unit -> string
Protected Overridable Function GetEmptyDesignTimeHtml As String

Return Value


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.


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.


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);
        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

      Return sw.ToString()
      Return GetEmptyDesignTimeHtml()
   End If
End Function
Version Information
.NET Framework
Available since 1.1
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