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DesignerAutoFormat Class
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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 System.Design.dll)

public abstract class DesignerAutoFormat

The DesignerAutoFormat type exposes the following members.

Protected methodDesignerAutoFormatInitializes a new instance of the DesignerAutoFormat class.

Public propertyNameGets the name of a DesignerAutoFormat object.
Public propertyStyleGets a DesignerAutoFormatStyle object that is used by the DesignerAutoFormat object to render a design-time preview of the associated control.

Public methodApplyApplies the associated formatting to the specified control.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetPreviewControlReturns a copy of the associated control in order to provide a preview before applying the format to the control.
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current DesignerAutoFormat object. (Overrides Object.ToString().)

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;

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

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