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WPF EventSetter Handler Command
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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：
<ListBox Grid.Row="" ItemsSource="{Binding DataList}"
MouseDoubleClick="ListBox_MouseDoubleClick"
SelectedItem="{Binding CurrentSelectItem}" Background="AliceBlue">
<ListBox.ItemTemplate>
<DataTemplate>
<DockPanel Height="" Background="DarkGray" Width="">
<TextBox Text="{Binding Name}" Height="" Width="" Background="DimGray"></TextBox>
</DockPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
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);
}
}
双击行就会出现双击的对象为空。
上一篇文章中已经说明怎么解决这个问题：
http://www.cnblogs.com/ligl/p/5629802.html
使用Style中的EventSetter Handler这里就不在更多介绍。
但是今天想要解决的问题是怎么把EventSetter Handler使用Command绑定的方式把Handler事件进行解耦
要使用第三方类库CommandBehavior(AttachedCommandBehavior acb)进行解耦
代码如下：
引用 xmlns:localCommand="clr-namespace:AttachedCommandBehavior"
<Style x:Key="listBox2Item" TargetType="ListBoxItem">
<Style.Setters>
<Setter Property="localCommand:CommandBehavior.Event" Value="MouseDoubleClick"></Setter>
<Setter Property="localCommand:CommandBehavior.Command" Value="{Binding DataContext.DoubleCommand,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type local:WinTest}}}"></Setter>
<Setter Property="localCommand:CommandBehavior.CommandParameter" Value="{Binding RelativeSource={RelativeSource Self}}"></Setter>
</Style.Setters>
</Style>
ViewModel代码如下
public class ViewModel : INotifyPropertyChanged
{
public ViewModel()
{
for (int i = ; i < ; i++)
{
DataList.Add(new ListBoxModel() { Name = "张三" + i.ToString(), Age = + i });
DataList2.Add(new ListBoxModel() { Name = "李四" + i.ToString(), Age = + 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);
}
}
}
完整Xaml和CS代码如下:
<Window x:Class="WpfTest.WinTest"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfTest"
xmlns:localCommand="clr-namespace:AttachedCommandBehavior"
mc:Ignorable="d"
Title="WinTest" Height="" Width="">
<Window.Resources>
<Style TargetType="TextBlock">
<Style.Setters>
<Setter Property="FontSize" Value=""></Setter>
</Style.Setters>
</Style> <Style TargetType="Button">
<Style.Setters>
<Setter Property="localCommand:CommandBehavior.Event" Value="MouseDoubleClick"></Setter>
<Setter Property="localCommand:CommandBehavior.Command" Value="{Binding DoubleCommand}"></Setter>
<Setter Property="localCommand:CommandBehavior.CommandParameter" Value="{Binding Path=DataContext, RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type local:WinTest}}}"></Setter>
</Style.Setters>
</Style> <Style x:Key="listBox2Item" TargetType="ListBoxItem">
<Style.Setters>
<Setter Property="localCommand:CommandBehavior.Event" Value="MouseDoubleClick"></Setter>
<Setter Property="localCommand:CommandBehavior.Command" Value="{Binding DataContext.DoubleCommand,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type local:WinTest}}}"></Setter>
<Setter Property="localCommand:CommandBehavior.CommandParameter" Value="{Binding RelativeSource={RelativeSource Self}}"></Setter>
</Style.Setters>
</Style>
<!--<Style x:Key="listBox2Item" TargetType="ListBoxItem">
<Style.Setters>
<EventSetter Event="MouseDoubleClick" Handler="ListBox2_MouseDoubleClick"></EventSetter>
</Style.Setters>
</Style>-->
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height=""></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
</Grid.RowDefinitions>
<StackPanel Orientation="Horizontal">
<StackPanel Margin="0 0 20 0">
<TextBlock Text="{Binding CurrentSelectItem.Name}"></TextBlock>
<TextBlock Text="{Binding CurrentSelectItem.Age}"></TextBlock>
</StackPanel> <StackPanel>
<TextBlock Text="{Binding CurrentSelectItem2.Name}">
</TextBlock>
<TextBlock Text="{Binding CurrentSelectItem2.Age}"></TextBlock>
</StackPanel> <Button Content="DoubleClick" ></Button>
</StackPanel> <ListBox Grid.Row="" ItemsSource="{Binding DataList}"
MouseDoubleClick="ListBox_MouseDoubleClick"
SelectedItem="{Binding CurrentSelectItem}" Background="AliceBlue">
<ListBox.ItemTemplate>
<DataTemplate>
<DockPanel Height="" Background="DarkGray" Width="">
<TextBox Text="{Binding Name}" Height="" Width="" Background="DimGray"></TextBox>
</DockPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox> <ListBox Grid.Row="" ItemsSource="{Binding DataList2}"
SelectedItem="{Binding CurrentSelectItem2}"
ItemContainerStyle="{StaticResource listBox2Item}"
Background="Silver">
<ListBox.ItemTemplate>
<DataTemplate>
<DockPanel Height="" Background="DarkOrange" Width="">
<TextBox Text="{Binding Name}" Height="" Width="" Background="DarkCyan"></TextBox>
</DockPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Window>
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 = ; i < ; i++)
{
DataList.Add(new ListBoxModel() { Name = "张三" + i.ToString(), Age = + i });
DataList2.Add(new ListBoxModel() { Name = "李四" + i.ToString(), Age = + 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;
}
}
<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
