公司WPF程序开发中应用了Caliburn框架，最近在做一个DataGrid上二级MenuItem时，发现Click方法无法调用ViewModel中的方法，但是回来后，在自己的机器上写了一个类似的测试程序时，却能够调用ViewModel中的方法
测试程序DataGrid
1 <DataGrid CanUserAddRows="False" AutoGenerateColumns="True" ItemsSource="{Binding Collection, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" 2 > 3 <DataGrid.ContextMenu> 4 <ContextMenu Name="menuList" > 5 <MenuItem Header="查看" cal:Message.Attach="[Event Click]=[Action Show()];"> 6 </MenuItem> 7 <MenuItem Header="修改一下"> 8 <MenuItem Header="修改" cal:Message.Attach="[Event Click]=[Action Modify()];"></MenuItem> 9 <MenuItem Header="删除" cal:Message.Attach="[Event Click]=[Action Delete()]"></MenuItem> 10 </MenuItem> 11 </ContextMenu> 12 </DataGrid.ContextMenu> 13 14 <DataGrid.Columns> 15 <DataGridTemplateColumn Header="姓名" Width="100"> 16 <DataGridTemplateColumn.CellTemplate> 17 <DataTemplate> 18 19 <TextBlock Text="{Binding Path=Name, Mode=TwoWay}"/> 20 </DataTemplate> 21 </DataGridTemplateColumn.CellTemplate> 22 </DataGridTemplateColumn> 23 24 <DataGridTemplateColumn Header="性别" Width="100"> 25 <DataGridTemplateColumn.CellTemplate> 26 <DataTemplate> 27 28 <TextBlock Text="{Binding Path=Sex, Mode=TwoWay}" /> 29 </DataTemplate> 30 </DataGridTemplateColumn.CellTemplate> 31 </DataGridTemplateColumn> 32 <DataGridTemplateColumn Header="年龄" Width="100"> 33 <DataGridTemplateColumn.CellTemplate> 34 <DataTemplate> 35 36 <TextBlock Text="{Binding Path=Age, Mode=TwoWay}"/> 37 </DataTemplate> 38 </DataGridTemplateColumn.CellTemplate> 39 </DataGridTemplateColumn> 40 </DataGrid.Columns> 41 </DataGrid>
ViewModel中对应的方法
1 public void Show() 2 { 3 MessageBox.Show("查看成功"); 4 } 5 6 public void Modify() 7 { 8 MessageBox.Show("修改成功"); 9 } 10 11 public void Delete() 12 { 13 MessageBox.Show("删除成功"); 14 }
在公司时，一级MenuItem中也无法调用ViewModel中的方法，原因应该是MenuItem与DataGrid不在一个视觉树中。由于无法复现问题，只能修改测试程序将我找到的解决方法贴出来。
1 <DataGrid CanUserAddRows="False" AutoGenerateColumns="True" ItemsSource="{Binding Collection, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" 2 > 3 <DataGrid.ContextMenu> 4 <ContextMenu Name="menuList" cal:Action.TargetWithoutContext="{Binding Path=PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}"> 5 <MenuItem Header="查看" cal:Message.Attach="[Event Click]=[Action Show()];"> 6 </MenuItem> 7 <MenuItem Header="修改一下"> 8 <MenuItem Header="修改" 9 cal:Action.TargetWithoutContext="{Binding Path=PlacementTarget.DataContext, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContextMenu}}" 10 cal:Message.Attach="[Event Click]=[Action Modify()];"> 11 </MenuItem> 12 <MenuItem Header="删除" 13 cal:Action.TargetWithoutContext="{Binding Path=PlacementTarget.DataContext, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContextMenu}}" 14 cal:Message.Attach="[Event Click]=[Action Delete()]"> 15 </MenuItem> 16 </MenuItem> 17 </ContextMenu> 18 </DataGrid.ContextMenu> 19 20 <DataGrid.Columns> 21 <DataGridTemplateColumn Header="姓名" Width="100"> 22 <DataGridTemplateColumn.CellTemplate> 23 <DataTemplate> 24 25 <TextBlock Text="{Binding Path=Name, Mode=TwoWay}"/> 26 </DataTemplate> 27 </DataGridTemplateColumn.CellTemplate> 28 </DataGridTemplateColumn> 29 30 <DataGridTemplateColumn Header="性别" Width="100"> 31 <DataGridTemplateColumn.CellTemplate> 32 <DataTemplate> 33 34 <TextBlock Text="{Binding Path=Sex, Mode=TwoWay}" /> 35 </DataTemplate> 36 </DataGridTemplateColumn.CellTemplate> 37 </DataGridTemplateColumn> 38 <DataGridTemplateColumn Header="年龄" Width="100"> 39 <DataGridTemplateColumn.CellTemplate> 40 <DataTemplate> 41 42 <TextBlock Text="{Binding Path=Age, Mode=TwoWay}"/> 43 </DataTemplate> 44 </DataGridTemplateColumn.CellTemplate> 45 </DataGridTemplateColumn> 46 </DataGrid.Columns> 47 </DataGrid>
参考自：http://stackoverflow.com/questions/13587368/no-target-found-for-method-thrown-by-caliburn-message-attach