wpf datagrid鼠標綁定leftdoubleclick命令只適用於已經選擇的項目

Question

我有一個DataGrid並希望在我的ViewModel中定義的命令在雙擊某行時執行。這在行已經被選中時工作，但是如果我雙擊一個當前未被選中的行，就不會這樣，即使我可以看到DataGrid的MouseDoubleClick事件觸發並且所需的行已成爲SelectedItem。這裏是我的DataGrid的定義：

<DataGrid Name="ProjectsList" Grid.Row="1" ItemsSource="{Binding FilteredProjects}" VerticalAlignment="Stretch" 
         HorizontalAlignment="Stretch" AutoGenerateColumns="False" CanUserAddRows="False" CanUserDeleteRows="False" 
         SelectedItem="{Binding SelectedProject}" PreviewMouseDoubleClick="ProjectsList_PreviewMouseDoubleClick" 
         MouseDoubleClick="ProjectsList_MouseDoubleClick" > 
    <interactivity:Interaction.Behaviors> 
     <behaviours:DataGridSelectedProjectsBehaviour SelectedProjects="{Binding SelectedProjects}" /> 
    </interactivity:Interaction.Behaviors> 
    <DataGrid.InputBindings> 
     <KeyBinding Key="Delete" Command="{Binding DeleteCommand}" /> 
     <MouseBinding MouseAction="LeftDoubleClick" Command="{Binding OpenCommand}" /> 
    </DataGrid.InputBindings> 
    <DataGrid.Columns> 
     <DataGridTemplateColumn Width="*"> 
      <DataGridTemplateColumn.CellTemplate> 
       <DataTemplate> 
        <Grid Margin="0,0,8,0"> 
         <Grid.ColumnDefinitions> 
          <ColumnDefinition Width="*" /> 
          <ColumnDefinition Width="Auto" /> 
         </Grid.ColumnDefinitions> 
         <Grid.RowDefinitions> 
          <RowDefinition /> 
          <RowDefinition /> 
          <RowDefinition /> 
          <RowDefinition /> 
         </Grid.RowDefinitions> 

         <Rectangle Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" Height="2"> 
          <Rectangle.Fill> 
           <LinearGradientBrush StartPoint="0,0" EndPoint="1,0"> 
            <GradientStop Color="{StaticResource SpruceGreen}" Offset="0" /> 
            <GradientStop Color="{StaticResource DarkGrey}" Offset="0.5" /> 
            <GradientStop Color="{StaticResource LightGrey}" Offset="1" /> 
           </LinearGradientBrush> 
          </Rectangle.Fill> 
         </Rectangle> 
         <TextBlock Grid.Column="0" Grid.Row="1" Text="{Binding Name}" FontWeight="Bold" /> 
         <TextBlock Grid.Column="1" Grid.Row="1" Text="{Binding State}" Foreground="Red" HorizontalAlignment="Right" Typography.Capitals="AllSmallCaps" /> 
         <TextBlock Grid.Column="0" Grid.Row="2" Grid.ColumnSpan="2" Text="{Binding Created, Converter={StaticResource StringFormat}, ConverterParameter='CREATED {0:dd/MM/yyyy HH:mm}'}" Foreground="Gray" FontSize="10" /> 
         <TextBlock Grid.Column="0" Grid.Row="3" Grid.ColumnSpan="2" Text="{Binding Description}" TextWrapping="Wrap" Padding="0,0,0,32" /> 
        </Grid> 
       </DataTemplate> 
      </DataGridTemplateColumn.CellTemplate> 
     </DataGridTemplateColumn> 
    </DataGrid.Columns> 
</DataGrid> 

下面是一些演示問題的日誌條目。請原諒我的調試日誌條目。以「>」結尾的日誌條目只是表示調用了方法（[]中的名稱）。 這是當我雙擊當前未選中的行會發生什麼：

2017/07/12 16:35:52 DEBUG (ThreadId:1) [DataGridSelectedProjectsBehaviour.OnDataGridSelectionChanged] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectViewModel.SelectedCollectionChanged] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectViewModel.get_SelectedTotal] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [DataGridSelectedProjectsBehaviour.ProjectsCollectionChanged] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectViewModel.SelectedCollectionChanged] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectViewModel.get_SelectedTotal] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [DataGridSelectedProjectsBehaviour.ProjectsCollectionChanged] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_PreviewMouseDoubleClick] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_PreviewMouseDoubleClick] - SelectedItem is project [Project2] 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_MouseDoubleClick] - > 
2017/07/12 16:35:52 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_MouseDoubleClick] - SelectedItem is project [Project2] 

這是當我雙擊行時當前選擇它會發生什麼：

2017/07/12 16:35:54 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_PreviewMouseDoubleClick] - > 
2017/07/12 16:35:54 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_PreviewMouseDoubleClick] - SelectedItem is project [Project2] 
2017/07/12 16:35:54 DEBUG (ThreadId:1) [<Open>d__35.MoveNext] - command was invoked. 
2017/07/12 16:35:54 INFO (ThreadId:1) [BaseViewModel.CheckForUnsavedChanges] - There are no unsaved changes. 
2017/07/12 16:35:54 DEBUG (ThreadId:1) [ProjectSummaryViewModel..ctor] - ViewModel was created. 
2017/07/12 16:35:54 DEBUG (ThreadId:1) [NavigationServiceEx.InternalNavigateTo] - SetParameter finished 
2017/07/12 16:35:54 DEBUG (ThreadId:1) [BaseViewModel.NavigatedFrom] - > 
2017/07/12 16:35:54 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_MouseDoubleClick] - > 
2017/07/12 16:35:54 DEBUG (ThreadId:1) [SelectProjectPage.ProjectsList_MouseDoubleClick] - SelectedItem is project [Project2] 

由於你可以看到，如果該行已被選中，則執行打開命令。

我以爲DataGridSelectedProjectsBehaviour可能干擾MouseBinding，但是當我刪除它時，雙擊命令從不起作用。我真的不需要它，並想刪除它。當預計需要多行選擇時添加它。

任何建議將不勝感激。由於

Answer 1

你可以嘗試處理MouseDoubleClick事件的DataGridRow容器，無論是從視圖的代碼隱藏調用命令：

<DataGrid Name="ProjectsList" Grid.Row="1" ItemsSource="{Binding FilteredProjects}" VerticalAlignment="Stretch" 
         HorizontalAlignment="Stretch" AutoGenerateColumns="False" CanUserAddRows="False" CanUserDeleteRows="False" 
         SelectedItem="{Binding SelectedProject}" PreviewMouseDoubleClick="ProjectsList_PreviewMouseDoubleClick" 
         MouseDoubleClick="ProjectsList_MouseDoubleClick" > 
    <DataGrid.RowStyle> 
     <Style TargetType="DataGridRow"> 
      <EventSetter Event="MouseDoubleClick" Handler="OnItemMouseDoubleClick" /> 
     </Style> 
    </DataGrid.RowStyle> 
    ... 
</DataGrid> 

---

private void OnItemMouseDoubleClick(object sender, ouseButtonEventArgs e) 
{ 
    var vm = this.DataContext as YourViewModel; 
    vm.YourCommand.Execute(null); 
} 

或通過使用附加行爲基本上做同樣的事情：

<Style TargetType="DataGridRow"> 
    <Setter Property="local:YourType.YourAttachedCommandProperty" Value="{Binding DataContext.YourCommand, RelativeSource={RelativeSource AncestorType=DataGrid}}" /> 
</Style>