接触WPF已经有两年，大大小小开发过几个项目，但从来没有系统的去学习过。几次开发项目时都觉得十分的恼火，太多的事件稍微考虑不到位就会带来麻烦，为此特地系统的看了一本《C#高级编程》第10版，了解到MVVM框架，看了之后十分欢喜，本篇记录研究MVVM过程。
0001 ICommand接口的实现
public class RelayCommand : ICommand
{
#region Fields
readonly Action<object> _execute;
readonly Predicate<object> _canExecute;
#endregion // Fields
#region Constructors
/// <summary>
/// Creates a new command that can always execute.
/// </summary>
/// <param name="execute">The execution logic.</param>
public RelayCommand(Action<object> execute)
: this(execute, null)
{
}
/// <summary>
/// Creates a new command.
/// </summary>
/// <param name="execute">The execution logic.</param>
/// <param name="canExecute">The execution status logic.</param>
public RelayCommand(Action<object> execute, Predicate<object> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
#endregion // Constructors
#region ICommand Members
[DebuggerStepThrough]
public bool CanExecute(object parameters)
{
return _canExecute == null ? true : _canExecute(parameters);
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public void Execute(object parameters)
{
_execute(parameters);
}
#endregion // ICommand Members
}
0010 不带参数的命令绑定
前台：
<Button x:Name="button" Content="添加" Command="{Binding AddTimeCommand}" HorizontalAlignment="Left" Margin="288,158,0,0" VerticalAlignment="Top" Width="89" Height="36">
</Button>后台：
RelayCommand _addTimeCommand = null;
public ICommand AddTimeCommand
{
get
{
if (null == _addTimeCommand)
{
_addTimeCommand = new RelayCommand((p) => OnAddTime(), (p) => CanAddTime());
}
return _addTimeCommand;
}
}
bool CanAddTime()
{
return true;
}
void OnAddTime()
{
MyDateTime.Add(DateTime.Now.ToString());
}
0011 带参数的命令绑定
前台：
<Button x:Name="button2" Content="修改" Command="{Binding ChangeTimeCommand}" CommandParameter="button2" HorizontalAlignment="Left" Margin="382,199,0,0" VerticalAlignment="Top" Width="89" Height="36">
</Button>后台：
public RelayCommand ChangeTimeCommand
{
get
{
return new RelayCommand(OnChangeTime, CanChangeTime);
}
}
bool CanChangeTime(object parameter)
{
return true;
}
void OnChangeTime(object parameter)
{
if (MyDateTime.Count > 0)
{
MyDateTime.RemoveAt(0);
MyDateTime.Insert(0, DateTime.Now.ToString());
}
}完