WPF EventSetter Handler Command

最近做一个工具，突然发现ListBox和ListView等列表控件的MouseDoubleClick事件有时候是获取不到当前双击的行对象数据的,比如这样写：

using AttachedCommandBehavior;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;

namespace WpfTest
{
/// <summary>
/// WinTest.xaml 的交互逻辑
/// </summary>
public partial class WinTest : Window
{
ViewModel VModel = new ViewModel();
public WinTest()
{
InitializeComponent();

this.DataContext = VModel;
}

private void ListBox_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
ListBox listBox = sender as ListBox;
if (listBox == null || listBox.SelectedItem == null)
{
MessageBox.Show("ListBox1双击对象为空...");
}
else
{
var model = listBox.SelectedItem as ListBoxModel;
MessageBox.Show("当前对象为" + model.Name + "  " + model.Age);
}
}

private void ListBox2_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
ListBoxItem listBoxItem = sender as ListBoxItem;
if (listBoxItem == null)
{
MessageBox.Show("ListBox2双击对象为空...");
}
else
{

ListBoxModel model = listBoxItem.Content as ListBoxModel;
if (model != null)
{
VModel.CurrentSelectItem2 = listBoxItem.Content as ListBoxModel;
MessageBox.Show(model.Name + "  " + model.Age);
}

}
}

}

public class ViewModel : INotifyPropertyChanged
{
public ViewModel()
{
for (int i = 0; i < 5; i++)
{
DataList.Add(new ListBoxModel() { Name = "张三" + i.ToString(), Age = 1000 + i });
DataList2.Add(new ListBoxModel() { Name = "李四" + i.ToString(), Age = 100 + i });
}
doubleCommand = new SimpleCommand(obj =>
{
ListBoxItem listBoxItem = obj as ListBoxItem;
if (listBoxItem != null)
{
ListBoxModel model = listBoxItem.Content as ListBoxModel;
if (model != null)
{
CurrentSelectItem2 = model;
MessageBox.Show("Command Banding" + model.Name + "  " + model.Age);
}
}
//wpftest.ViewModel
MessageBox.Show("Cmd...");
}, o => true);
}

public SimpleCommand DoubleCommand
{
get
{
return doubleCommand;
}

set
{
doubleCommand = value;
//OnPropertyChanged(new PropertyChangedEventArgs("DoubleCommand"));
}
}

private ObservableCollection<ListBoxModel> dataList = new ObservableCollection<ListBoxModel>();

private ObservableCollection<ListBoxModel> _dataList2 = new ObservableCollection<ListBoxModel>();

private ListBoxModel _CurrentSelectItem;

private ListBoxModel _CurrentSelectItem2;

private SimpleCommand doubleCommand;

public ObservableCollection<ListBoxModel> DataList
{
get
{
return dataList;
}

set
{
dataList = value;
}
}

/// <summary>
/// 当前双击的对象
/// </summary>
public ListBoxModel CurrentSelectItem
{
get
{
return _CurrentSelectItem;
}

set
{
_CurrentSelectItem = value;
OnPropertyChanged(new PropertyChangedEventArgs("CurrentSelectItem"));
}
}

/// <summary>
/// ListBox2双击的对象
/// </summary>
public ListBoxModel CurrentSelectItem2
{
get
{
return _CurrentSelectItem2;
}

set
{
_CurrentSelectItem2 = value;
OnPropertyChanged(new PropertyChangedEventArgs("CurrentSelectItem2"));
}
}

public ObservableCollection<ListBoxModel> DataList2
{
get
{
return _dataList2;
}

set
{
_dataList2 = value;
}
}

public event PropertyChangedEventHandler PropertyChanged;

public void OnPropertyChanged(PropertyChangedEventArgs e)
{
if (PropertyChanged != null)
{
PropertyChanged(this, e);
}
}
}

public class ListBoxModel : INotifyPropertyChanged
{
/// <summary>
/// 姓名
/// </summary>
private string _Name;

/// <summary>
/// 年龄
/// </summary>
private int _Age;

public string Name
{
get
{
return _Name;
}

set
{
_Name = value;
OnPropertyChanged(new PropertyChangedEventArgs("Name"));
}
}

public int Age
{
get
{
return _Age;
}

set
{
_Age = value;
OnPropertyChanged(new PropertyChangedEventArgs("Age"));
}
}

public void OnPropertyChanged(PropertyChangedEventArgs e)
{
if (PropertyChanged != null)
{
PropertyChanged(this, e);
}
}

public event PropertyChangedEventHandler PropertyChanged;
}
}

View Code

<Setter Property="localCommand:CommandBehavior.Command" Value="{Binding DataContext.DoubleCommand,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type local:WinTest}}}"></Setter>

关于这个Command的Value绑定要使用FindAncestor进行查找才能解决,不然是绑定不到ViewModel中的DoubleCommand

发个图看看：


关于CommandBehavior代码可以在

http://download.csdn.net/download/doncle000/7029327 下载使用

国外博客http://marlongrech.wordpress.com/2008/12/04/attachedcommandbehavior-aka-acb/

对于SimpleCommad.cs的源文件我增加了两个参数的构造函数：

public SimpleCommand(Action<object> execute, Predicate<object> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
CanExecuteDelegate = canExecute;
ExecuteDelegate = execute;
}

源代码下载地址