Question

目标

目标是在双击选定行时执行命令。

问题

当我双击一个单元格时，它进入编辑模式并且不执行命令。

如果我双击列 Data 右侧的空单元格 - 它会执行命令。

此外，如果我将 IsReadOnly 设置为 true，它会起作用.. 它只是不适用于可编辑的单元格。

问题

为什么双击事件对可编辑单元格不起作用？

重现问题的代码

XAML

<DataGrid ItemsSource="{Binding SampleModels}" SelectedItem="{Binding SelectedItem}" AutoGenerateColumns="True" >
    <DataGrid.InputBindings>
        <MouseBinding Gesture="LeftDoubleClick" Command="{Binding Command}" />
    </DataGrid.InputBindings>
</DataGrid>

模型

public class SampleModel
{
    public int Id { get; set; }
    public string Data { get; set; }
}

查看模型

public class SampleViewModel : BaseViewModel
{
    public ObservableCollection<SampleModel> SampleModels { get; set; }

    private SampleModel _selectedItem;

    public SampleModel SelectedItem
    {
        get { return _selectedItem; }
        set
        {
            _selectedItem = value;
            OnPropertyChanged();
        }
    }

    private void LoadData()
    {
        if(SampleModels == null)
        {
            SampleModels = new ObservableCollection<SampleModel>();
        }
        SampleModels.Clear();

        SampleModels.Add(new SampleModel { Id = 1, Data = "Item 1" });
        SampleModels.Add(new SampleModel { Id = 2, Data = "Item 2" });
    }

    public ICommand Command { get; }
    private void TestMethod()
    {
        var a = SelectedItem;
    }


    public SampleViewModel()
    {
        LoadData();
        Command = new RelayCommand(param => TestMethod());
    }

}

Answer 1

<块引用>

为什么双击事件对可编辑单元格不起作用？

因为 DataGrid 控件通过进入单元格的编辑模式来处理双击。您还能如何编辑单元格？

您可以使用附加行为处理单元格中的双击：

public static class DoubleClickBehavior
{
    public static ICommand GetCommand(UIElement element) =>
        (ICommand)element.GetValue(CommandProperty);

    public static void SetCommand(UIElement element, ICommand value) =>
        element.SetValue(CommandProperty, value);

    public static readonly DependencyProperty CommandProperty =
        DependencyProperty.RegisterAttached(
        "Command",
        typeof(ICommand),
        typeof(DoubleClickBehavior),
        new UIPropertyMetadata(null, OnChanged));

    private static void OnChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        UIElement element = (UIElement)d;
        if (e.NewValue is ICommand command)
        {
            element.PreviewMouseLeftButtonDown += OnMouseLeftButtonDown;
        }
        else
        {
            element.PreviewMouseLeftButtonDown -= OnMouseLeftButtonDown;
        }
    }

    private static void OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        if (e.ClickCount == 2)
        {
            UIElement element = (UIElement)sender;
            ICommand command = GetCommand(element);
            if (command != null)
                command.Execute(null);
        }
    }
}

示例用法：

<DataGrid ItemsSource="{Binding SampleModels}" SelectedItem="{Binding SelectedItem}" AutoGenerateColumns="True" >
    <DataGrid.InputBindings>
        <MouseBinding Gesture="LeftDoubleClick" Command="{Binding Command}" />
    </DataGrid.InputBindings>
    <DataGrid.CellStyle>
        <Style TargetType="DataGridCell">
            <Setter Property="local:DoubleClickBehavior.Command"
                    Value="{Binding DataContext.Command,RelativeSource={RelativeSource AncestorType=DataGrid}}" />
        </Style>
    </DataGrid.CellStyle>
</DataGrid>

DataGrid 不会在可编辑单元格上执行双击事件

1 个答案: