如何拖动动态创建的图片框？

Question

所以，我有一个带有背景图像（图片框）和一些拼图块（动态创建的图片框，命名为 pic[i]）的表单。

我在 for 循环中有这段代码来创建这些片段。

    pic[i].MouseDown += new MouseEventHandler(picMouseDown);
    pic[i].MouseMove += new MouseEventHandler(picMouseMove);
    pic[i].MouseUp += new MouseEventHandler(picMouseUp);

下面我展示了相应的事件。

    int x = 0;
    int y = 0;
    bool drag = false;

    private void picMouseDown(object sender, MouseEventArgs e)
    {
        // Get original position of cursor on mousedown
        x = e.X;
        y = e.Y;
        drag = true;
    }

    private void picMouseMove(object sender, MouseEventArgs e)
    {
        if (drag)
        {
            // Get new position of picture
            pic[i].Top += e.Y - y;    //this i here is wrong
            pic[i].Left += e.X - x;
            pic[i].BringToFront();
        }
    }

    private void picMouseUp(object sender, MouseEventArgs e)
    {
        drag = false;
    }

所以，我知道在“picMouseMove”内部，“i”具有 for 循环结束时的值。

我想做的是在“picMouseMove”事件中获取 pic[i] id，以便用户可以成功拖动拼图。

Answer 1

您需要将sender转换为PictureBox。然后您就可以像知道它的名字一样访问它。

简单的改变

private void picMouseMove(object sender, MouseEventArgs e)
{
    if (drag)
    {
        // Get new position of picture
        pic[i].Top += e.Y - y;    //this i here is wrong
        pic[i].Left += e.X - x;
        pic[i].BringToFront();
    }
}

到

private void picMouseMove(object sender, MouseEventArgs e)
{
    if (drag)
    {
        PictureBox pb = (PictureBox ) sender;
        // Get new position of picture
        pb.Top += e.Y - y;    
        pb.Left += e.X - x;
        pb.BringToFront();
    }
}