DesignerAutoFormat Class

Definition

public ref class DesignerAutoFormat abstract

public abstract class DesignerAutoFormat

type DesignerAutoFormat = class

Public MustInherit Class DesignerAutoFormat

Inheritance

Object

DesignerAutoFormat

Examples

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
    [Designer(typeof(IndentLabelDesigner)), 
        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), 
            PersistenceMode(PersistenceMode.Attribute)]
        public int Indent
        {
            get { return _indent; }
            set
            {
                _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");
                else
                    this.Style.Remove(HtmlTextWriterStyle.MarginLeft);
            }
        }
    }

    // A design-time ControlDesigner for the IndentLabel control
    [SupportsPreviewControl(true)]
    public class IndentLabelDesigner : LabelDesigner
    {
        private DesignerAutoFormatCollection _autoFormats = null;

        // The collection of AutoFormat objects for the IndentLabel object
        public override DesignerAutoFormatCollection AutoFormats
        {
            get
            {
                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
                        ctl.MergeStyle(this.Style);
                    }
                    else
                    {
                        // For the Default format, apply style elements to the control
                        ctl.ForeColor = Color.Black;
                        ctl.BackColor = Color.Empty;
                        ctl.Font.Size = FontUnit.XSmall;
                    }
                }
            }
        }
    }
}

Imports System.Drawing
Imports System.Collections
Imports System.ComponentModel
Imports System.Web.UI
Imports System.Web.UI.Design
Imports System.Web.UI.Design.WebControls
Imports System.Web.UI.WebControls

Namespace CustomControls.Design

    ' A custom Label control whose contents can be indented
    <Designer(GetType(IndentLabelDesigner)), _
        ToolboxData("<{0}:IndentLabel Runat=""server""></{0}:IndentLabel>")> _
    Public Class IndentLabel
        Inherits System.Web.UI.WebControls.Label

        Dim _indent As Integer = 0

        <Category("Appearance"), DefaultValue(0), _
            PersistenceMode(PersistenceMode.Attribute)> _
        Property Indent() As Integer
            Get
                Return _indent
            End Get
            Set(ByVal Value As Integer)
                _indent = Value

                ' Get the number of pixels to indent
                Dim ind As Integer = _indent * 8

                ' Add the indent style to the control
                If ind > 0 Then
                    Me.Style.Add(HtmlTextWriterStyle.MarginLeft, ind.ToString() & "px")
                Else
                    Me.Style.Remove(HtmlTextWriterStyle.MarginLeft)
                End If
            End Set
        End Property

    End Class

    ' A design-time ControlDesigner for the IndentLabel control
    Public Class IndentLabelDesigner
        Inherits LabelDesigner

        Private _autoFormats As DesignerAutoFormatCollection = Nothing
        ' The collection of AutoFormat objects for the IndentLabel object
        Public Overrides ReadOnly Property AutoFormats() As DesignerAutoFormatCollection
            Get
                If _autoFormats Is Nothing Then
                    ' 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"))
                End If

                Return _autoFormats
            End Get
        End Property

        ' An AutoFormat object for the IndentLabel control
        Public Class IndentLabelAutoFormat
            Inherits DesignerAutoFormat

            Public Sub New(ByVal name As String)
                MyBase.New(name)
            End Sub

            ' Applies styles based on the Name of the AutoFormat
            Public Overrides Sub Apply(ByVal inLabel As Control)
                If TypeOf inLabel Is IndentLabel Then
                    Dim ctl As IndentLabel = CType(inLabel, IndentLabel)

                    ' Apply formatting according to the Name
                    If Me.Name.Equals("MyClassic") Then
                        ' 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"
                    ElseIf Me.Name.Equals("MyBright") Then
                        ' For MyBright, apply style elements to the Style object
                        Me.Style.ForeColor = Color.Maroon
                        Me.Style.BackColor = Color.Yellow
                        Me.Style.Font.Size = FontUnit.Medium

                        ' Merge the AutoFormat style with the control's style
                        ctl.MergeStyle(Me.Style)
                    Else
                        ' For the Default format, apply style elements to the control
                        ctl.ForeColor = Color.Black
                        ctl.BackColor = Color.Empty
                        ctl.Font.Size = FontUnit.XSmall
                    End If
                End If
            End Sub
        End Class
    End Class

End Namespace

Remarks

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 Implementers

When you inherit from the DesignerAutoFormat class, you must override the Apply(Control) method to preview a formatted control and to apply the selected format to your control.

Constructors

Properties

Methods

Applies to

See also

• DesignerAutoFormatCollection
• DesignerAutoFormatStyle
• AutoFormats
• ControlDesigner
• ASP.NET Control Designers Overview