DesignerAutoFormatCollection Class
Assembly: System.Design (in system.design.dll)
The ControlDesigner class and any derived class defines the AutoFormats property as a DesignerAutoFormatCollection object. Control developers can override the AutoFormats property in a derived control designer, add custom automatic formatting styles, and return the collection of supported formats to the visual designer.
The collection dynamically increases as objects are added. Indexes in this collection are zero-based. Use the Count property to determine how many automatic style formats are in the collection.
Additionally, use the DesignerAutoFormatCollection methods and properties to provide the following functionality:
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The Add method to add a single format to the collection.
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The Insert method to add a format at a particular index within the collection.
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The Remove method to remove a format.
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The RemoveAt method to remove the format at a particular index.
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The Contains method to determine whether a particular format is already in the collection.
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The IndexOf method to retrieve the index of a format within the collection.
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The Item property to get or set the format at a particular index, using array notation.
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The Clear method to remove all formats from the collection.
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The Count property to determine the number of formats in the collection.
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The IndexOf method to get the position of a format within the collection.
The following code example demonstrates how to implement the AutoFormats property 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; } } } } } }