1、创建一个 ViewModelBase
public abstract class ViewModelBase : INotifyPropertyChanged{
//属性改变事件
public event PropertyChangedEventHandler PropertyChanged;
//当属性改变的时候，调用该方法来发起一个消息，通知View中绑定了propertyName的元素做出调整
public void RaisePropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
2、创建一个DelegateCommand
public class DelegateCommand : ICommand{
readonly Action<object> _execute;
readonly Predicate<object> _canExecute;
public DelegateCommand(Action<object> execute)
: this(execute, null)
{
}
public DelegateCommand(Action<object> execute, Predicate<object> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
public void Execute(object parameter)
{
_execute(parameter);
}
public bool CanExecute(object parameter)
{
return _canExecute == null ? true : _canExecute(parameter);
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
}
