关于wpf：命令绑定到ContextMenu(在ListBox中的ListBoxItem上)不起作用

Command bind to ContextMenu (which on ListBoxItem in ListBox) don't work

本问题已经有最佳答案，请猛点这里访问。

在WPF中，使用MVVM指示灯，有一个Class(由一些学生组成)，而Class包含一些Student。

enter image description here

右键单击一个学生的名字，然后显示MessageBox，这样就可以了：

ClassDetailView.xaml

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但是，它不能以这种方式工作(使用ListBox.ItemContainerStyle)：

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<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="ContextMenu">
<Setter.Value>
<ContextMenu DataContext="{Binding Path=PlacementTarget, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Show Selected"
Command="{Binding Path=DataContext.RemoveStudentCommand}"
CommandParameter="{Binding Path=SelectedItem}"/>
</ContextMenu>
</Setter.Value>
</Setter>
</Style>
</ListBox.ItemContainerStyle>

代替

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<ListBox.ContextMenu>
<ContextMenu ...>
...
<ContextMenu />
</ListBox.ContextMenu>

ClassDetailViewModel.cs

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namespace ContextMenu.ViewModel
{
public class ClassDetailViewModel : ViewModelBase
{
public ClassDetailViewModel()
{
CreateData();
}

public void CreateData()
{
students.Add(new StudentViewModel() { Name ="QQ" });
students.Add(new StudentViewModel() { Name ="WW" });
students.Add(new StudentViewModel() { Name ="EE" });
students.Add(new StudentViewModel() { Name ="RR" });
students.Add(new StudentViewModel() { Name ="AA" });
students.Add(new StudentViewModel() { Name ="SS" });
students.Add(new StudentViewModel() { Name ="DD" });
students.Add(new StudentViewModel() { Name ="FF" });
students.Add(new StudentViewModel() { Name ="ZZ" });
students.Add(new StudentViewModel() { Name ="XX" });
}

public const string StudentsPropertyName ="Students";
private ObservableCollection<StudentViewModel> students =
new ObservableCollection<StudentViewModel>();
public ObservableCollection<StudentViewModel> Students
{
get { return students; }
set
{
if (students == value) { return; }
students = value;
RaisePropertyChanged(StudentsPropertyName);
}
}

private RelayCommand<StudentViewModel> removeStudentCommand;
public RelayCommand<StudentViewModel> RemoveStudentCommand
{
get
{
return removeStudentCommand
?? (removeStudentCommand =
new RelayCommand<StudentViewModel>(ExecuteRemoveStudentCommand));
}
}
private void ExecuteRemoveStudentCommand(StudentViewModel student)
{
if (null == student) { return; }
MessageBox.Show(string.Format("RemoveStudent:{0}", student.Name));
}
}
}

StudentViewModel.cs

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namespace ContextMenu.ViewModel
{
public class StudentViewModel : ViewModelBase
{
public const string NamePropertyName ="Name";
private string name ="";
public string Name
{
get { return name; }
set
{
if (name == value) { return; }
name = value;
RaisePropertyChanged(NamePropertyName);
}
}
}
}

您需要一个代理将命令绑定到listboxitem的上下文菜单。看到答案：

[WPF] How to bind to data when the DataContext is not inherited

相关讨论

你可以使用contextmenu作为资源吗？

就像是：

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<UserControl.Resources>

<ContextMenu x:name="contextMenuExample" DataContext="{Binding Path=PlacementTarget, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Show Selected"
Command="{Binding Path=DataContext.RemoveStudentCommand}"
CommandParameter="{Binding Path=SelectedItem}"/>
</ContextMenu>
</UserControl.Resources>

然后在列表上，执行以下操作：

1	<Listbox ContextMenu = {StaticResource contextMenuExample} ... />

或者你真的想使用ItemContainerStyle吗？

from - >如何右键单击列表框中的项目并打开WPF上的菜单

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