Wpf 将DoubleClick命令从DataGrid行绑定到VM

我有一个Datagrid，不喜欢在我的viewmodel上为单击（也称为选中）行触发双击命令

视图：

...

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;
        }
    }

public图标命令和mousedoubleclick命令
{
得到
{
if（mouseDoubleClickCommand==null）
{
mouseDoubleClickCommand=新的RelayCommand(
args=>
{
var sender=args.OriginalSource作为DependencyObject；
if（发送方==null）
{
返回；
}
var祖先=VisualTreeHelpers.FindAncestor（发送方）；
if（祖先！=null）
{
Send（newfinddeailsmessage（this，SelectedItem.Name，false））；
}
}
);
}
返回mousedoubleclick命令；
}
}

我想去掉视图模型中与视图相关的代码（带有依赖项对象和可视化树辅助对象的代码），因为这在某种程度上破坏了可测试性。但是从另一方面来说，我避免了当用户不点击一行而是点击标题时发生的事情

---

PS：我尝试查看附加行为，但我无法在工作时从Skydrive下载，因此“内置”解决方案最好。

您可以尝试以下解决方法：

<DataGrid  EnableRowVirtualization="True"
          ItemsSource="{Binding SearchItems}"
          SelectedItem="{Binding SelectedItem}"
          SelectionMode="Single"
          SelectionUnit="FullRow">
    <DataGrid.Columns>
        <DataGridTemplateColumn Header=".....">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                        <TextBlock .....>
                            <i:Interaction.Triggers>
                                <i:EventTrigger EventName="MouseDoubleClick">
                                    <cmd:EventToCommand Command="{Binding MouseDoubleClickCommand}" PassEventArgsToCommand="True" />
                                </i:EventTrigger>
                            </i:Interaction.Triggers>
                        </TextBlock>
                </DataTemplate>
    ...................

...................

---

在这种情况下，您必须为

DataGrid

中的每一列指定

DataTemplate

，以下是使用附加行为实现它的方法：

EDIT:现在注册

DataGridRow

上的行为，而不是

DataGrid

，以便忽略

DataGridHeader

单击

行为：

public class Behaviours
{
    public static DependencyProperty DoubleClickCommandProperty =
       DependencyProperty.RegisterAttached("DoubleClickCommand", typeof(ICommand), typeof(Behaviours),
                                           new PropertyMetadata(DoubleClick_PropertyChanged));

    public static void SetDoubleClickCommand(UIElement element, ICommand value)
    {
        element.SetValue(DoubleClickCommandProperty, value);
    }

    public static ICommand GetDoubleClickCommand(UIElement element)
    {
        return (ICommand)element.GetValue(DoubleClickCommandProperty);
    }

    private static void DoubleClick_PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var row = d as DataGridRow;
        if (row == null) return;

        if (e.NewValue != null)
        {
            row.AddHandler(DataGridRow.MouseDoubleClickEvent, new RoutedEventHandler(DataGrid_MouseDoubleClick));
        }
        else
        {
            row.RemoveHandler(DataGridRow.MouseDoubleClickEvent, new RoutedEventHandler(DataGrid_MouseDoubleClick));
        }
    }

    private static void DataGrid_MouseDoubleClick(object sender, RoutedEventArgs e)
    {
        var row= sender as DataGridRow;

        if (row!= null)
        {
            var cmd = GetDoubleClickCommand(row);
            if (cmd.CanExecute(row.Item))
                cmd.Execute(row.Item);
        }
    }
}

    <DataGrid x:Name="grid" EnableRowVirtualization="True"
          SelectedItem="{Binding SelectedItem}"
          SelectionMode="Single"
          SelectionUnit="FullRow" ItemsSource="{Binding SearchItems}">
       <DataGrid.RowStyle>
           <Style TargetType="DataGridRow">
                <Setter Property="Behaviours.DoubleClickCommand" Value="{Binding ElementName=grid, Path=DataContext.SortStateCommand}"/>
           </Style>
       </DataGrid.RowStyle>

Xaml:

public class Behaviours
{
    public static DependencyProperty DoubleClickCommandProperty =
       DependencyProperty.RegisterAttached("DoubleClickCommand", typeof(ICommand), typeof(Behaviours),
                                           new PropertyMetadata(DoubleClick_PropertyChanged));

    public static void SetDoubleClickCommand(UIElement element, ICommand value)
    {
        element.SetValue(DoubleClickCommandProperty, value);
    }

    public static ICommand GetDoubleClickCommand(UIElement element)
    {
        return (ICommand)element.GetValue(DoubleClickCommandProperty);
    }

    private static void DoubleClick_PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var row = d as DataGridRow;
        if (row == null) return;

        if (e.NewValue != null)
        {
            row.AddHandler(DataGridRow.MouseDoubleClickEvent, new RoutedEventHandler(DataGrid_MouseDoubleClick));
        }
        else
        {
            row.RemoveHandler(DataGridRow.MouseDoubleClickEvent, new RoutedEventHandler(DataGrid_MouseDoubleClick));
        }
    }

    private static void DataGrid_MouseDoubleClick(object sender, RoutedEventArgs e)
    {
        var row= sender as DataGridRow;

        if (row!= null)
        {
            var cmd = GetDoubleClickCommand(row);
            if (cmd.CanExecute(row.Item))
                cmd.Execute(row.Item);
        }
    }
}

    <DataGrid x:Name="grid" EnableRowVirtualization="True"
          SelectedItem="{Binding SelectedItem}"
          SelectionMode="Single"
          SelectionUnit="FullRow" ItemsSource="{Binding SearchItems}">
       <DataGrid.RowStyle>
           <Style TargetType="DataGridRow">
                <Setter Property="Behaviours.DoubleClickCommand" Value="{Binding ElementName=grid, Path=DataContext.SortStateCommand}"/>
           </Style>
       </DataGrid.RowStyle>

---

然后，您需要修改您的

mousedoubleclick命令

以删除

MouseButtonEventArgs

参数，并将其替换为您的

SelectedItem

类型。

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>

---

比这里提出的任何解决方案都简单

我用这个

<!-- 
requires IsSynchronizedWithCurrentItem
for more info on virtualization/perf https://stackoverflow.com/questions/9949358/datagrid-row-virtualization-display-issue 
 -->
        <DataGrid ItemsSource="{Binding SearchItems}" 
                  IsSynchronizedWithCurrentItem="True"
                  AutoGenerateColumns="false" CanUserAddRows="False" CanUserDeleteRows="False" IsReadOnly="True" EnableRowVirtualization="True"
                  >

            <!-- for details on ICollection view (the magic behind {Binding Accounts/} https://marlongrech.wordpress.com/2008/11/22/icollectionview-explained/ -->

            <DataGrid.InputBindings>
                <MouseBinding
                    MouseAction="LeftDoubleClick"
                    Command="{Binding MouseDoubleClickCommand}"
                    CommandParameter="{Binding SearchItems/}" />
            </DataGrid.InputBindings>
        </DataGrid>

---

从

中，问题不是获取所选项目（它在虚拟机上仍然是数据绑定的），而是获取在双击数据网格的标题时不执行的命令。如果要阻止鼠标双击，可以尝试预览鼠标双击，并将e.Handled=true设置为您的条件。因此，您可以从viewmodel中重新编译代码，并将其放入codebehind中，以实现您的datagridGreat想法。事实上，我一直在为OnContextMenuoOpening编写代码。有时候，你只是在正确的时间没有正确的想法。谢谢我将把这个标记为答案。在

myGrd

中保留“I”可以节省多少时间和精力？：-）InputBindings对我不起作用，因为它只在双击DataGrid头而不是行时起作用。您还可以使用

InvokeCommandAction

代替MVVM Light的

EventToCommand

。此行为是System.Windows.Interactivity DLL的一部分。它几乎等同于

EventToCommand

，但没有一些高级功能。我想这会奏效，但如果我必须在这两者之间做出选择，我可能会坚持我的方法。如果我更改列，我总是要为每一列重复您的XAML代码。我喜欢这是一个近乎完美（读作最佳）的解决方案。毕竟，这就是attched事件的目的：感谢您提供的初始链接源-它非常有用。阅读此评论的其他人：请特别注意CommandParameter属性值（即“SearchItems/”）末尾的正斜杠。

<!-- 
requires IsSynchronizedWithCurrentItem
for more info on virtualization/perf https://stackoverflow.com/questions/9949358/datagrid-row-virtualization-display-issue 
 -->
        <DataGrid ItemsSource="{Binding SearchItems}" 
                  IsSynchronizedWithCurrentItem="True"
                  AutoGenerateColumns="false" CanUserAddRows="False" CanUserDeleteRows="False" IsReadOnly="True" EnableRowVirtualization="True"
                  >

            <!-- for details on ICollection view (the magic behind {Binding Accounts/} https://marlongrech.wordpress.com/2008/11/22/icollectionview-explained/ -->

            <DataGrid.InputBindings>
                <MouseBinding
                    MouseAction="LeftDoubleClick"
                    Command="{Binding MouseDoubleClickCommand}"
                    CommandParameter="{Binding SearchItems/}" />
            </DataGrid.InputBindings>
        </DataGrid>