DataListDesigner.GetDesignTimeHtml Method ()


Gets the HTML used to represent the DataList control at design time.

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

public override string GetDesignTimeHtml()

Return Value

Type: System.String

The HTML that is used to represent the DataList control at design time.

The following code example shows how to override the GetDesignTimeHtml method. It alters the appearance of the control on the design surface if the control's WebControl.Enabled property is true.

The code uses Try...Catch...Finally syntax to do the following:

  • The Try section changes the values of the properties of the control.

  • The Catch section catches any exceptions and sends them to the GetErrorDesignTimeHtml method.

  • The Finally section sets the properties to their original values.

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

public override string GetDesignTimeHtml()
    string designTimeHtml = String.Empty;

    simpleGView = (SimpleGridView)Component;

    // Check the control's BorderStyle property to  
    // conditionally render design-time HTML.
    if (simpleGView.BorderStyle == BorderStyle.NotSet)
        // Save the current property settings in variables.
        int oldCellPadding = simpleGView.CellPadding;
        Unit oldBorderWidth = simpleGView.BorderWidth;
        Color oldBorderColor = simpleGView.BorderColor;

        // Set properties and generate the design-time HTML.
            simpleGView.Caption = "SimpleGridView";
            simpleGView.CellPadding = 1;
            simpleGView.BorderWidth = Unit.Pixel(3);
            simpleGView.BorderColor = Color.Red;

            designTimeHtml = base.GetDesignTimeHtml();
        catch (Exception ex)
            // Get HTML from the GetErrorDesignTimeHtml 
            // method if an exception occurs.
            designTimeHtml = GetErrorDesignTimeHtml(ex);

            // Return the properties to their original values.
            simpleGView.CellPadding = oldCellPadding;
            simpleGView.BorderWidth = oldBorderWidth;
            simpleGView.BorderColor = oldBorderColor;
        designTimeHtml = base.GetDesignTimeHtml();

    return designTimeHtml;

protected override string
    GetErrorDesignTimeHtml(System.Exception exc)
    return CreatePlaceHolderDesignTimeHtml(
        "ASPNET.Examples: An error occurred while rendering the GridView.");


.NET Framework
Available since 1.1
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