GetEmptyDesignTimeHtml Method
.NET Framework Class Library
ControlDesigner..::.GetEmptyDesignTimeHtml 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)
Visual Basic (Declaration)
Protected Overridable Function GetEmptyDesignTimeHtml As String
Visual Basic (Usage)
Dim returnValue As String

returnValue = Me.GetEmptyDesignTimeHtml()
C#
protected virtual string GetEmptyDesignTimeHtml()
Visual C++
protected:
virtual String^ GetEmptyDesignTimeHtml()
JScript
protected function GetEmptyDesignTimeHtml() : String

Return Value

Type: System..::.String
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.

Visual Basic
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
C#
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();
}

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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