Question

嘿，我在我的WPF MVVM应用程序中使用DataGrid，就像这样

        <DataGrid x:Name="SearchGrid"
              ...>
        <DataGrid.Columns>
            <DataGridTemplateColumn Width="Auto" Header="Type">
                <DataGridTemplateColumn.CellTemplate>
                   ...
                </DataGridTemplateColumn.CellTemplate>
            </DataGridTemplateColumn>
            <DataGridTextColumn Width="6*"
                                Binding="{Binding Reference}"
                                Header="Reference" />
            <DataGridTextColumn Width="9*"
                                Binding="{Binding Description}"
                                Header="Description" />
        </DataGrid.Columns>
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="MouseDoubleClick">
                <cmd:EventToCommand Command="{Binding Path=SelectElementCommand, Mode=OneWay}" CommandParameter="{Binding SelectedItem, ElementName=SearchGrid}" />
            </i:EventTrigger>
        </i:Interaction.Triggers>
    </DataGrid>

当我双击网格中的一行时，执行'SelectElementCommand'，当我点击标题时，行将被排序。到目前为止一切都还可以。但是，当我双击一个标题时，该命令也会被执行。怎么阻止？

感谢您的帮助。

Answer 1

您可以通过将鼠标DoubleClick EventArgs传递给命令来执行此操作：

<i:Interaction.Triggers>
        <i:EventTrigger EventName="MouseDoubleClick">
            <cmd:EventToCommand Command="{Binding Path=SelectElementCommand, Mode=OneWay}" PassEventArgsToCommand="True" />
        </i:EventTrigger>
    </i:Interaction.Triggers>

和相应的SelectElementCommand如下所示：

 private RelayCommand<MouseButtonEventArgs> _selectElementCommand;
    public RelayCommand<MouseButtonEventArgs> SelectElementCommand
    {
        get
        {
            return _selectElementCommand
                ?? (_selectElementCommand= new RelayCommand<MouseButtonEventArgs>(
                    (s) =>
                    {
                        var dep = s.OriginalSource as DependencyObject;
                        //go up the treeView until you find the ColumnHeader if existed 
                        while (dep != null && !(dep is DataGridColumnHeader))
                        {
                            dep = VisualTreeHelper.GetParent(dep);
                        }

                        if (!(dep is DataGridColumnHeader))
                            //you handler logic 

                    }));
        }
    }

我不明白为什么你将SelectedItem作为CommandParametre传递，因为你可以简单地将它定义为ViewModel中的属性：

 private YourRowType  _selectedItem ;
    public YourRowType SelectedItem 
    {
        get
        {
            return _selectedItem;
        }

        set
        {
            if (_selectedItem == value)
            {
                return;
            }

            _selectedItem = value;
            RaisePropertyChanged();
        }
    }

如何禁用DataGridColumn标头的命令？

1 个答案: