Question

缩略语

我想从名单到流动语言。

概览一

private void listViewGUI_DragEnter(object sender, DragEventArgs e)
        {
}

and in the FlowLayoutPanel I activate the DragDrop

private void fpnlDisplayedGUI_DragDrop(object sender, DragEventArgs e)
        {
}

问题在于,它不从事任何此类活动,而如果我没有任何财产,那么我会知道如何让他们进入。

最佳做法

Answer 1

以下是你需要的basics的简单例子:

public Form1()
{
    InitializeComponent();

    panel1.MouseDown += new MouseEventHandler(panel1_MouseDown);
    panel2.AllowDrop = true;
    panel2.DragEnter += new DragEventHandler(panel2_DragEnter);
    panel2.DragDrop += new DragEventHandler(panel2_DragDrop);
}

void panel2_DragDrop(object sender, DragEventArgs e)
{
    //handle the drop here.
}

void panel2_DragEnter(object sender, DragEventArgs e)
{
    e.Effect = DragDropEffects.Move;
}

void panel1_MouseDown(object sender, MouseEventArgs e)
{
    panel1.DoDragDrop("whatever you want draged.", DragDropEffects.Move);
}

Answer 2

You put the DragEnter event on the wrong control, you must use the panel s. I think I know how you got into this trouble, ListView doesn t have any event that indicates the user started dragging an item. You ll need to synthesize that yourself. The basic approach is to record the mouse down position and use the MouseMove event to check if the user has moved the mouse far enough to start a drag. Like this:

    private Point dragMousePos;

    private void listView1_MouseDown(object sender, MouseEventArgs e) {
        if (e.Button == MouseButtons.Left) dragMousePos = e.Location;
    }

    private void listView1_MouseMove(object sender, MouseEventArgs e) {
        if (e.Button == MouseButtons.Left) {
            int dx = Math.Abs(e.X - dragMousePos.X);
            int dy = Math.Abs(e.Y - dragMousePos.Y);
            if (dx >= SystemInformation.DoubleClickSize.Width ||
                dy >= SystemInformation.DoubleClickSize.Height) {
                var item = listView1.GetItemAt(dragMousePos.X, dragMousePos.Y);
                if (item != null) listView1.DoDragDrop(item, DragDropEffects.Move);
            }
        }
    }

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