c# - 在 WPF (C#) 中的两个 Datagrid 之间拖放

Question

对不起我的英语，这不是我的母语。如果您有什么不明白的地方，请告诉我。

我开始使用 C# 和 WPF，我需要在两个数据网格之间实现拖放功能。我已经搜索了很多，但没有找到任何对我有帮助的东西。它总是显示如何在两个不同的控件之间或仅在同一个数据网格中进行拖放，并且我无法根据我的需要调整这些答案，因为我不理解解决方案的某些部分。所以我来这里是想问一个非常精确的问题:如何在两个数据网格之间实现拖放？

如果你能帮助我，我将不胜感激。

Answer 1

这是一个示例代码 ( More Details here )

1. 定义鼠标按下事件
2. 定义 MouseMove 事件以启动 DragAndDrop 操作
3. 定义 DragOver 以测试是否允许放置
4. 定义Drop事件做drop操作

您可以为两个数据网格使用相同的事件

    private Point? _startPoint;

    private void dataGrid_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        _startPoint = e.GetPosition(null);
    }

    private void dataGrid_PreviewMouseMove(object sender, MouseEventArgs e)
    {
        // No drag operation
        if (_startPoint == null)
            return;

        var dg = sender as DataGrid;
        if (dg == null) return; 
        // Get the current mouse position
        Point mousePos = e.GetPosition(null);
        Vector diff = _startPoint.Value - mousePos;
        // test for the minimum displacement to begin the drag
        if (e.LeftButton == MouseButtonState.Pressed &&
            (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance ||
            Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance))
        {

            // Get the dragged DataGridRow
            var DataGridRow=
                FindAnchestor<DataGridRow>((DependencyObject)e.OriginalSource);

            if (DataGridRow == null)
                return;
            // Find the data behind the DataGridRow
            var dataTodrop = (DataModel)dg.ItemContainerGenerator.
                ItemFromContainer(DataGridRow);

            if (dataTodrop == null) return;

            // Initialize the drag & drop operation
            var dataObj = new DataObject(dataTodrop);
            dataObj.SetData("DragSource", sender);
            DragDrop.DoDragDrop(dg, dataObj, DragDropEffects.Copy);
            _startPoint = null;
        }
    }

    private void dataGrid_PreviewMouseUp(object sender, MouseButtonEventArgs e)
    {
        _startPoint = null;
    }

    private void dataGrid_Drop(object sender, DragEventArgs e)
    {
        var dg = sender as DataGrid;
        if (dg == null) return;
        var dgSrc = e.Data.GetData("DragSource") as DataGrid;
        var data = e.Data.GetData(typeof(DataModel));
        if (dgSrc == null || data == null) return;
        // Implement move data here, depends on your implementation
        MoveDataFromSrcToDest(dgSrc, dg, data);
        // OR
        MoveDataFromSrcToDest(dgSrc.DataContext, dg.DataContext, data);
    }

    private void dataGrid_PreviewDragOver(object sender, DragEventArgs e)
    {
         // TO test if drop is allowed, to avoid drop 
         // if false e.Effects = DragDropEffects.None;
    }


    // Helper to search up the VisualTree
    private static T FindAnchestor<T>(DependencyObject current)
        where T : DependencyObject
    {
        do
        {
            if (current is T)
            {
                return (T)current;
            }
            current = VisualTreeHelper.GetParent(current);
        }
        while (current != null);
        return null;
    }

希望这有帮助:)