c# – DataGridView多行选择清除鼠标左键拖放

我正在尝试实现Drag&在标准DataGridView上删除多行.

我按住控制键和鼠标左键选择3行.然后我释放控制键以及选择要拖动的行的内容.因此,使用鼠标左键单击并按住其中一行上的按钮,以便我可以开始拖动动作.

但是,只要我单击其中一行,就会选择该行,并取消选择其他两行,这样我就不再移动3行了.

我怎样才能解决这个问题？如果我释放鼠标左键(没有ctrl键),我只希望再次突出显示该行.这就是Windows资源管理器的工作原理.

我在Visual Studio 2010中使用C#4.0.

解决方法:

我在项目中遇到了这个问题 – 如何允许用户使用标准方法在datagridview中选择一堆行,然后将选择拖到另一个数据网格视图并删除它.我能够构建一个来自http://www.codeproject.com/Tips/338594/Drag-drop-multiple-selected-rows-of-datagridview-w的想法,它只是将DataGridView子类化为“可拖动的”DataGridView,当用户按下已经选择的行上的按钮时捕获鼠标操作,同时允许所有其他情况的标准行为：

public partial class DraggableDataGridView : System.Windows.Forms.DataGridView {

    private Rectangle dragBoxFromMouseDown;

    protected override void onm ouseDown(MouseEventArgs e) {

        // Trap the case where the user pressed the left mouse button on an already-selected row
        // without <shift> or <control>

        if ((e.Button & MouseButtons.Left) == MouseButtons.Left
            && Control.ModifierKeys == Keys.None
            && this.SelectedRows.Count > 0
            && HitTest(e.X, e.Y).RowIndex >= 0
            && this.SelectedRows.Contains(this.Rows[HitTest(e.X, e.Y).RowIndex])
            ) {

                // User pressed the mouse button over an already-selected row without <shift> or <control> so we should 
                // consider drag and drop. Record a rectangle around that mouse location to possibly trigger drag
                // operation

                Debug.WriteLine("MouseDown inside selection");
                Size dragSize = SystemInformation.DragSize;
                dragBoxFromMouseDown = new Rectangle(new Point(e.X - (dragSize.Width / 2), e.Y - (dragSize.Height / 2)), dragSize);

        } else {
            // In other cases use the default behavior for datagridview
            Debug.WriteLine("MouseDown outside selection");
            dragBoxFromMouseDown = Rectangle.Empty;
            base.OnMouseDown(e);
        }
    }

    protected override void onm ouseUp(MouseEventArgs e) {
        base.OnMouseUp(e);
    }

    protected override void onm ouseMove(MouseEventArgs e) {
        if ((e.Button & MouseButtons.Left) == MouseButtons.Left) {
            // If the mouse moves outside the drag limit rectangle, start the drag.
            if (dragBoxFromMouseDown != Rectangle.Empty && !dragBoxFromMouseDown.Contains(e.Location)) {
                // Proceed with the drag and drop, passing in the selected rows
                DragDropEffects dropEffect =
                        this.DoDragDrop(this.SelectedRows, DragDropEffects.Move);
            }
        }
        base.OnMouseMove(e);
    }

    public DraggableDataGridView() {
        InitializeComponent();
    }

    protected override void OnPaint(PaintEventArgs pe) {
        base.OnPaint(pe);
    }
}

拥有此代码,然后将此自定义组件替换为表单中的所有DataGridViews允许我将它们用作标准拖动源,并以通常的方式将它们“插入”其他组件的标准拖放功能.

标签：c,datagridview,multi-select
来源： https://codeday.me/bug/20190709/1409601.html