ASP.NET.in.a.Nutshell.Second.Edition [Electronic resources]

This is base class for web control designers like System.Web.UI.Design.WebControls.AdRotatorDesigner. These designers create the design-time appearance that a control provides to the design editor (like Visual Studio .NET). This HTML code is provided through the GetDesignTimeHtml( ) method, which is called by the host. The base implementation of the GetDesignTimeHtml( ) method invokes the System.Web.UI.Control.Render( ) method of the appropriate control to create the same HTML at design time as at runtime. A custom designer modifies this behavior by overriding the GetDesignTimeHtml( ) to provide HTML that is more suitable for a design-time representation.

You can create your own custom designer to use with a custom System.Web.UI.WebControls.WebControl. In this case, you use the System.ComponentModel.DesignerAttribute on the class declaration of your control to connect it with the appropriate designer. You can set various ControlDesigner propertiesthe most useful of which is AllowResize, which restricts your control to a fixed size. When your control is resized, the designer will call corresponding methods like OnControlResize( ) to give you a chance to refresh the appearance of your control accordingly. At this point you can call UpdateDesignTimeHtml( ), which instructs the host to call your GetDesignTimeHtml( ) method and refresh the control display with the new content.

The GetDesignTimeHtml( ) method should call GetEmptyDesignTimeHtml( ) if the rendered HTML string is empty (for example, when required control properties are not set). The base implementation of GetEmptyDesignTimeHtml( ) returns the fully qualified name of the control. Alternatively, you may want to override this property to supply a place holder using the CreatePlaceHolderDesignTimeHtml( ). You may also want to override GetErrorDesignTimeHtml( ) method with specific information based on the exception object that is provided.

public class 
ControlDesigner  : HtmlControlDesigner {
// Public Constructors
public 
ControlDesigner ( );
// Public Instance Properties
public virtual bool 
AllowResize {get; }
public virtual bool 
DesignTimeHtmlRequiresLoadComplete {get; }
public virtual string 
ID {set; get; }
public bool 
IsDirty {set; get; }
public bool 
ReadOnly {set; get; }
// Protected Instance Properties
protected object 
DesignTimeElementView {get; }
// Public Instance Methods
public virtual string 
GetDesignTimeHtml ( );
public virtual string 
GetPersistInnerHtml ( );
public override void 
Initialize (System.ComponentModel.IComponent 
component );
// overrides System.ComponentModel.Design.ComponentDesigner
public bool 
IsPropertyBound (string 
propName );
public virtual void 
OnComponentChanged (object 
sender , 
System.ComponentModel.Design.ComponentChangedEventArgs 
ce );
public void 
RaiseResizeEvent ( );
public virtual void 
UpdateDesignTimeHtml ( );
// Protected Instance Methods
protected string 
CreatePlaceHolderDesignTimeHtml ( );
protected string 
CreatePlaceHolderDesignTimeHtml (string 
instruction );
protected virtual string 
GetEmptyDesignTimeHtml ( );
protected virtual string 
GetErrorDesignTimeHtml (Exception 
e );
protected override void 
OnBehaviorAttached ( );   // overrides HtmlControlDesigner
protected override void 
OnBindingsCollectionChanged (string 
propName );  // overrides HtmlControlDesigner
protected virtual void 
OnControlResize ( );
protected override void 
PreFilterProperties (System.Collections.IDictionary 
properties ); 
// overrides HtmlControlDesigner
}

Hierarchy

System.Object System.ComponentModel.Design.ComponentDesigner(System.ComponentModel.Design.IDesigner, System.IDisposable, System.ComponentModel.Design.IDesignerFilter) HtmlControlDesigner ControlDesigner

Subclasses

Multiple types