DesignerAutoFormat Class

Provides the abstract base class for creating formats that can be applied to a custom Web server control at design time.

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

public abstract class DesignerAutoFormat
public abstract class DesignerAutoFormat
public abstract class DesignerAutoFormat
Not applicable.

DesignerAutoFormat provides a base class that can be inherited from and extended to display a formatted custom Web server control at design time in a visual designer tool such as Visual Studio 2005.

A control developer provides automatic formatting in order to help developers who use the control to select a preferred display. A custom DesignerAutoFormat object works with a custom control designer to provide automatic formatting at design time for a custom control. For example, the Calendar control provides a variety of formats that can be applied by a developer at design time.

To implement automatic formatting for a custom control:

  1. Create the custom control.

  2. Derive a designer class from the ControlDesigner class or another designer class that is appropriate for your control, such as the TextControlDesigner.

  3. Derive a format class from the DesignerAutoFormat class that formats your custom control by overriding the Apply method.

  4. In your designer class, populate the AutoFormats property, which is a DesignerAutoFormatCollection object, with one instance of your format class for each named format that your designer can apply.

The DesignerAutoFormat class provides the following members to support automatic formatting at design time:

  • The Apply method, which applies the named format to the specified control.

  • The GetPreviewControl method, which provides a copy of the control for previewing in an AutoFormat dialog box of a visual designer such as Visual Studio 2005.

  • The Name property, which provides the text to display in a list of formats in a visual designer.

Notes to Inheritors: When you inherit from the DesignerAutoFormat class, you must override the Apply method to preview a formatted control and to apply the selected format to your control.

The following code example demonstrates how to implement automatic formatting in a custom control designer. The derived control designer implements the AutoFormats property by adding three instances of a custom automatic format that are derived from the DesignerAutoFormat class.

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Web.UI;
using System.Web.UI.Design;
using System.Web.UI.Design.WebControls;
using System.Web.UI.WebControls;

namespace CustomControls.Design.CS
	// A custom Label control whose contents can be indented
        ToolboxData("<{0}:IndentLabel Runat=\"server\"></{0}:IndentLabel>")]
    public class IndentLabel : Label
        private int _indent = 0;

        // Property to indent all text within the label
        [Category("Appearance"), DefaultValue(0), 
        public int Indent
            get { return _indent; }
                _indent = value;
                // Get the number of pixels to indent
                int ind = value * 8;

                //  Add the indent style to the control
                if (ind > 0)
                    this.Style.Add(HtmlTextWriterStyle.MarginLeft, ind.ToString() + "px");

	// A design-time ControlDesigner for the IndentLabel control
    public class IndentLabelDesigner : LabelDesigner
        private DesignerAutoFormatCollection _autoFormats = null;

		// The collection of AutoFormat objects for the IndentLabel object
        public override DesignerAutoFormatCollection AutoFormats
                if (_autoFormats == null)
					// Create the collection
                    _autoFormats = new DesignerAutoFormatCollection();

					// Create and add each AutoFormat object
                    _autoFormats.Add(new IndentLabelAutoFormat("MyClassic"));
                    _autoFormats.Add(new IndentLabelAutoFormat("MyBright"));
                    _autoFormats.Add(new IndentLabelAutoFormat("Default"));
                return _autoFormats;

	    // An AutoFormat object for the IndentLabel control
        private class IndentLabelAutoFormat : DesignerAutoFormat
		    public IndentLabelAutoFormat(string name) : base(name)
		    { }

		    // Applies styles based on the Name of the AutoFormat
            public override void Apply(Control inLabel)
                if (inLabel is IndentLabel)
                    IndentLabel ctl = (IndentLabel)inLabel;

				    // Apply formatting according to the Name
                    if (this.Name == "MyClassic")
					    // For MyClassic, apply style elements directly to the control
                        ctl.ForeColor = Color.Gray;
                        ctl.BackColor = Color.LightGray;
                        ctl.Font.Size = FontUnit.XSmall;
                        ctl.Font.Name = "Verdana,Geneva,Sans-Serif";
                    else if (this.Name == "MyBright")
					    // For MyBright, apply style elements to the Style property
                        this.Style.ForeColor = Color.Maroon;
					    this.Style.BackColor = Color.Yellow;
					    this.Style.Font.Size = FontUnit.Medium;

					    // Merge the AutoFormat style with the control's style
					    // For the Default format, apply style elements to the control
                        ctl.ForeColor = Color.Black;
                        ctl.BackColor = Color.Empty;
                        ctl.Font.Size = FontUnit.XSmall;


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0