The GetErrorDesignTimeHtml method is typically called, if an exception is thrown in the GetDesignTimeHtml method.

The typical design pattern is to try to get HTML markup through the associated control, and then if an error is encountered, call the GetErrorDesignTimeHtml method. If no markup is returned by the control, call the GetEmptyDesignTimeHtml method, which if it is not overridden to provide specific markup, calls the CreatePlaceHolderDesignTimeHtml method, which should contain information about the type and ID of the control.

The following code example demonstrates how to generate design-time HTML markup for the control when an error occurs and call the CreatePlaceHolderDesignTimeHtml method.

' Generate the design-time markup for the control when an error occurs.
Protected Overrides Function GetErrorDesignTimeHtml( _
    ByVal ex As Exception) As String

    ' Write the error message text in red, bold.
    Dim errorRendering As String = _
        "<span style=""font-weight:bold; color:Red; "">" & _
        ex.Message & "</span>"

    Return CreatePlaceHolderDesignTimeHtml(errorRendering)

End Function ' GetErrorDesignTimeHtml

// Generate the design-time markup for the control when an error occurs.
protected override string GetErrorDesignTimeHtml(Exception e) 
{
    // Write the error message text in red, bold.
    string errorRendering =
        "<span style=\"font-weight:bold; color:Red; \">" +
        e.Message + "</span>";

    return CreatePlaceHolderDesignTimeHtml(errorRendering);
} // GetErrorDesignTimeHtml

• Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.

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

.NET Framework

Reference

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