将 DataGrid 行中的 DoubleClick 命令绑定到 VM [英] Bind DoubleClick Command from DataGrid Row to VM

问题描述

我有一个 Datagrid，但我不喜欢我的解决方法来在我的视图模型上为单击(又名选定)行触发双击命令.

I have a Datagrid and don't like my workaround to fire a double click command on my viewmodel for the clicked (aka selected) row.

查看:

   <DataGrid  EnableRowVirtualization="True"
              ItemsSource="{Binding SearchItems}"
              SelectedItem="{Binding SelectedItem}"
              SelectionMode="Single"
              SelectionUnit="FullRow">

        <i:Interaction.Triggers>
            <i:EventTrigger EventName="MouseDoubleClick">
                <cmd:EventToCommand Command="{Binding MouseDoubleClickCommand}" PassEventArgsToCommand="True" />
            </i:EventTrigger>
        </i:Interaction.Triggers>
        ...
  </DataGrid>

视图模型:

    public ICommand MouseDoubleClickCommand
    {
        get
        {
            if (mouseDoubleClickCommand == null)
            {
                mouseDoubleClickCommand = new RelayCommand<MouseButtonEventArgs>(
                    args =>
                    {
                        var sender = args.OriginalSource as DependencyObject;
                        if (sender == null)
                        {
                            return;
                        }
                        var ancestor = VisualTreeHelpers.FindAncestor<DataGridRow>(sender);
                        if (ancestor != null)
                        {
                            MessengerInstance.Send(new FindDetailsMessage(this, SelectedItem.Name, false));
                        }
                    }
                    );
            }
            return mouseDoubleClickCommand;
        }
    }

我想在我的视图模型中摆脱与视图相关的代码(具有依赖对象和可视化树助手的代码)，因为这会以某种方式破坏可测试性.但另一方面，这样我可以避免当用户不点击行而是点击标题时发生某些事情.

I want to get rid of the view related code (the one with the dependency object and the visual tree helper) in my view model, as this breaks testability somehow. But on the other hand this way I avoid that something happens when the user doesn't click on a row but on the header for example.

PS:我尝试查看附加行为，但无法在工作时从 Skydrive 下载，因此最好使用内置"解决方案.

PS: I tried having a look at attached behaviors, but I cannot download from Skydrive at work, so a 'built in' solution would be best.

推荐答案

为什么不直接使用CommandParameter?

<DataGrid x:Name="myGrd"
          ItemsSource="{Binding SearchItems}"
          SelectedItem="{Binding SelectedItem}"
          SelectionMode="Single"
          SelectionUnit="FullRow">

    <i:Interaction.Triggers>
        <i:EventTrigger EventName="MouseDoubleClick">
            <cmd:EventToCommand Command="{Binding MouseDoubleClickCommand}"  
                                CommandParameter="{Binding ElementName=myGrd, Path=SelectedItem}" />
        </i:EventTrigger>
    </i:Interaction.Triggers>
    ...
</DataGrid>

你的命令是这样的:

public ICommand MouseDoubleClickCommand
{
    get
    {
        if (mouseDoubleClickCommand == null)
        {
            mouseDoubleClickCommand = new RelayCommand<SearchItem>(
                item =>
                {
                    var selectedItem = item;
                });
        }

        return mouseDoubleClickCommand;
    }
}

我现在使用它而不是 Interaction.Triggers:

I now use this instead of Interaction.Triggers:

<DataGrid.InputBindings>
    <MouseBinding MouseAction="LeftDoubleClick"
                  Command="{Binding Path=MouseDoubleClickCommand}"
                  CommandParameter="{Binding ElementName=myGrd, Path=SelectedItem}" />
</DataGrid.InputBindings>

这篇关于将 DataGrid 行中的 DoubleClick 命令绑定到 VM的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！