private void UpdateEnabledState()
{
if (_enabledPropertyInfo == null)
{
return;
}
var commandParameter = _commandParameterBinding.GetBindingValue();
_enabledPropertyInfo.SetValue(_element, _command.CanExecute(commandParameter));
}
/// <summary>
/// Initializes a new instance of the <see cref="CommandBinding"/> class.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="eventName">Name of the event.</param>
/// <param name="command">The command.</param>
/// <param name="commandParameterBinding">The command parameter binding.</param>
/// <exception cref="ArgumentNullException">The <paramref name="element"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException">The <paramref name="eventName"/> is <c>null</c> or whitespace.</exception>
/// <exception cref="ArgumentNullException">The <paramref name="command"/> is <c>null</c>.</exception>
public CommandBinding(object element, string eventName, ICatelCommand command, Binding commandParameterBinding = null)
{
Argument.IsNotNull("element", element);
Argument.IsNotNullOrWhitespace("eventName", eventName);
Argument.IsNotNull("command", command);
_element = element;
_command = command;
_commandParameterBinding = commandParameterBinding;
var elementType = _element.GetType();
_eventInfo = elementType.GetEventEx(eventName);
if (_eventInfo == null)
{
Log.ErrorAndThrowException <InvalidOperationException>("Event '{0}.{1}' not found, cannot create command binding", elementType.Name, eventName);
}
_enabledPropertyInfo = elementType.GetPropertyEx("Enabled");
_eventHandler = delegate
{
var commandParameter = _commandParameterBinding.GetBindingValue();
if (_command.CanExecute(commandParameter))
{
_command.Execute(commandParameter);
}
};
_eventInfo.AddEventHandler(element, _eventHandler);
_canExecuteChangedHandler = (sender, e) => UpdateEnabledState();
command.CanExecuteChanged += _canExecuteChangedHandler;
if (commandParameterBinding != null)
{
_commandBindingParameterValueChangedHandler = (sender, e) => UpdateEnabledState();
commandParameterBinding.ValueChanged += _commandBindingParameterValueChangedHandler;
}
UpdateEnabledState();
}
/// <summary>
/// Initializes a new instance of the <see cref="CommandBinding"/> class.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="eventName">Name of the event.</param>
/// <param name="command">The command.</param>
/// <param name="commandParameterBinding">The command parameter binding.</param>
/// <exception cref="ArgumentNullException">The <paramref name="element"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException">The <paramref name="eventName"/> is <c>null</c> or whitespace.</exception>
/// <exception cref="ArgumentNullException">The <paramref name="command"/> is <c>null</c>.</exception>
public CommandBinding(object element, string eventName, ICatelCommand command, Binding commandParameterBinding = null)
{
Argument.IsNotNull("element", element);
Argument.IsNotNullOrWhitespace("eventName", eventName);
Argument.IsNotNull("command", command);
_element = element;
_command = command;
_commandParameterBinding = commandParameterBinding;
var elementType = _element.GetType();
_eventInfo = elementType.GetEventEx(eventName);
if (_eventInfo == null)
{
throw Log.ErrorAndCreateException<InvalidOperationException>("Event '{0}.{1}' not found, cannot create command binding", elementType.Name, eventName);
}
_enabledPropertyInfo = elementType.GetPropertyEx("Enabled");
_eventHandler = delegate
{
var commandParameter = _commandParameterBinding.GetBindingValue();
if (_command.CanExecute(commandParameter))
{
_command.Execute(commandParameter);
}
};
_eventInfo.AddEventHandler(element, _eventHandler);
_canExecuteChangedHandler = (sender, e) => UpdateEnabledState();
command.CanExecuteChanged += _canExecuteChangedHandler;
if (commandParameterBinding != null)
{
_commandBindingParameterValueChangedHandler = (sender, e) => UpdateEnabledState();
commandParameterBinding.ValueChanged += _commandBindingParameterValueChangedHandler;
}
UpdateEnabledState();
}