windowsforms-18004-controls-and-libraries-spreadsheet-examples-commands-how-to-replace-built-in-command-with-a-custom-command.md
This example illustrates the technique used to modify the functionality of the existing SpreadsheetControl command used to clear the contents of the selected cell.
The SpreadsheetControl exposes the ISpreadsheetCommandFactoryService interface that enables you to substitute the default command with your own custom command.
You have to create a custom command class, inherited from the command that you wish to replace. In this example, it is the DevExpress.XtraSpreadsheet.Commands.FormatClearContentsCommand class. Override the ExecuteCore method to specify actions performed by a command when it is executed.
public class CustomFormatClearContentsCommand : FormatClearContentsCommand {
public CustomFormatClearContentsCommand(ISpreadsheetControl control)
: base(control) {
}
protected override void ExecuteCore() {
MessageBox.Show("Custom command executed");
base.ExecuteCore();
}
}
Public Class CustomFormatClearContentsCommand
Inherits FormatClearContentsCommand
Public Sub New(ByVal control As ISpreadsheetControl)
MyBase.New(control)
End Sub
Protected Overrides Sub ExecuteCore()
MessageBox.Show("Custom command executed")
MyBase.ExecuteCore()
End Sub
End Class
Create a class inherited from the SpreadsheetCommandFactoryServiceWrapper. This class will replace the default command service. In this class, you should override the CreateCommand method to create an instance of a custom command class. An identifier of the currently processed command is passed as a parameter to this method.
public class CustomService : SpreadsheetCommandFactoryServiceWrapper {
public CustomService(ISpreadsheetCommandFactoryService service)
: base(service) {
}
public SpreadsheetControl Control {get;set;}
public override SpreadsheetCommand CreateCommand(SpreadsheetCommandId id)
{
if (id == SpreadsheetCommandId.FormatClearContents || id == SpreadsheetCommandId.FormatClearContentsContextMenuItem)
return new CustomFormatClearContentsCommand(Control);
return base.CreateCommand(id);
}
}
Public Class CustomService
Inherits SpreadsheetCommandFactoryServiceWrapper
Public Sub New(ByVal service As ISpreadsheetCommandFactoryService)
MyBase.New(service)
End Sub
Public Property Control() As SpreadsheetControl
Public Overrides Function CreateCommand(ByVal id As SpreadsheetCommandId) As SpreadsheetCommand
If id = SpreadsheetCommandId.FormatClearContents OrElse id = SpreadsheetCommandId.FormatClearContentsContextMenuItem Then
Return New CustomFormatClearContentsCommand(Control)
End If
Return MyBase.CreateCommand(id)
End Function
End Class
Use the SpreadsheetCommandFactoryServiceWrapper class descendant to substitute the default command service obtained using the SpreadsheetControl.GetService<T> method.
private void SubstituteService() {
ISpreadsheetCommandFactoryService service = (ISpreadsheetCommandFactoryService)spreadsheetControl1.GetService(typeof(ISpreadsheetCommandFactoryService));
CustomService customService = new CustomService(service);
spreadsheetControl1.ReplaceService<ISpreadsheetCommandFactoryService>(customService);
customService.Control = spreadsheetControl1;
}
Private Sub SubstituteService()
Dim service As ISpreadsheetCommandFactoryService = DirectCast(spreadsheetControl1.GetService(GetType(ISpreadsheetCommandFactoryService)), ISpreadsheetCommandFactoryService)
Dim customService As New CustomService(service)
spreadsheetControl1.ReplaceService(Of ISpreadsheetCommandFactoryService)(customService)
customService.Control = spreadsheetControl1
End Sub
Now, instead of clearing the contents of the selected cell, you will get the message “Custom command executed”.