RoutedCommand.Execute Method

The actual logic that executes the RoutedCommand is not contained in the Execute methods. Execute raises the PreviewExecuted and Executed events, which tunnel and bubble through the element tree looking for an object with a CommandBinding. If a CommandBinding for that RoutedCommand is found, then the ExecutedRoutedEventHandler attached to CommandBinding is called. These handlers supply the programming logic that performs the RoutedCommand.

The PreviewExecuted and Executed events are raised on the CommandTarget. If the CommandTarget is not set on the ICommandSource, the PreviewExecuted and Executed events are raised on the element with keyboard focus.

The following example is from a custom implementation of ICommandSource sample. The full sample subclasses the Slider class and implements ICommandSource to create a slider that invokes a command when its value property is changed. For the complete sample, see Implement ICommandSource Sample.

this.Command in this example is the Command property on the ICommandSource. If the command is not null, the command is cast to a RoutedCommand. If it is a RoutedCommand, then the Execute method is called passing the CommandTarget and the CommandParameter. If the command is not a RoutedCommand, it is cast to an ICommand and the Execute method is called passing the CommandParameter.

// If Command is defined, moving the slider will invoke the command; 
// Otherwise, the slider will behave normally. 
protected override void OnValueChanged(double oldValue, double newValue)
{
    base.OnValueChanged(oldValue, newValue);

    if (this.Command != null)
    {
        RoutedCommand command = Command as RoutedCommand;

        if (command != null)
        {
            command.Execute(CommandParameter, CommandTarget);
        }
        else
        {
            ((ICommand)Command).Execute(CommandParameter);
        }
    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Reference

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