How to: Customize Built-in Command Using Service Substitution
- 3 minutes to read
Use the service substitution technique to customize the built-in command. Create the IRichEditCommandFactoryService descendant which generates custom commands and use the RichEditControl.ReplaceService<T> method (or the GetService -> RemoveService -> AddService method sequence) to replace default service with a newly created service.
The following code implements the IRichEditCommandFactoryService descendant which generates customized SaveDocumentCommand and SaveDocumentAsCommand commands. The command descendants override the ExecuteCore methods to display a message after a document has been saved.
Note
A complete sample project is available at https://github.com/DevExpress-Examples/winforms-the-richeditcontrols-common-api-t210437
public class CustomRichEditCommandFactoryService : IRichEditCommandFactoryService
{
readonly IRichEditCommandFactoryService service;
readonly RichEditControl control;
public CustomRichEditCommandFactoryService(RichEditControl control, IRichEditCommandFactoryService service)
{
DevExpress.Utils.Guard.ArgumentNotNull(control, "control");
DevExpress.Utils.Guard.ArgumentNotNull(service, "service");
this.control = control;
this.service = service;
}
public RichEditCommand CreateCommand(RichEditCommandId id)
{
if(id == RichEditCommandId.FileSaveAs) {
return new CustomSaveDocumentAsCommand(control);
}
if(id == RichEditCommandId.FileSave) {
return new CustomSaveDocumentCommand(control);
}
return service.CreateCommand(id);
}
}
public class CustomSaveDocumentCommand : SaveDocumentCommand
{
public CustomSaveDocumentCommand(IRichEditControl richEdit) : base(richEdit) { }
protected override void ExecuteCore()
{
base.ExecuteCore();
if(!(this.Control as RichEditControl).Modified)
{
MessageBox.Show("Document is saved successfully");
}
}
}
public class CustomSaveDocumentAsCommand : SaveDocumentAsCommand
{
public CustomSaveDocumentAsCommand(IRichEditControl richEdit) : base(richEdit)
{ }
protected override void ExecuteCore()
{
(this.Control as RichEditControl).Modified = true;
base.ExecuteCore();
if(!(this.Control as RichEditControl).Modified)
{
MessageBox.Show("Document is saved successfully");
}
}
}
The following code replaces the IRichEditCommandFactoryService service with its customized descendant.
richEditControl.Text = "A message box is displayed after saving a document using the 'Save' or 'Save As' button click since custom commands.";
var myCommandFactory = new CustomRichEditCommandFactoryService(richEditControl, richEditControl.GetService<IRichEditCommandFactoryService>());
richEditControl.ReplaceService<IRichEditCommandFactoryService>(myCommandFactory);