拖放移动图片框-拖动时图像的大小 [英] Drag and Drop move PictureBox- size of image when I'm dragging

问题描述

我创建了一种在拖放时移动图片框的方法.但是当我拖动图片框时，图像具有图像的实际大小，我希望图像具有图片框的大小

I have created a method which move the PictureBox when I Drag and Drop. But when I'm dragging the PictureBox, the image has the real size of image and I wanna that the image has the size of PictureBox

 private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            picBox = (PictureBox)sender;
            var dragImage = (Bitmap)picBox.Image;
            IntPtr icon = dragImage.GetHicon();
            Cursor.Current = new Cursor(icon);
            DoDragDrop(pictureBox1.Image, DragDropEffects.Copy);
            DestroyIcon(icon);
        }
    }

protected override void OnGiveFeedback(GiveFeedbackEventArgs e)
    {
        e.UseDefaultCursors = false;
    }
    protected override void OnDragEnter(DragEventArgs e)
    {
        if (e.Data.GetDataPresent(typeof(Bitmap))) e.Effect = DragDropEffects.Copy;
    }
    protected override void OnDragDrop(DragEventArgs e)
    {

        picBox.Location = this.PointToClient(new Point(e.X - picBox.Width / 2, e.Y - picBox.Height / 2));
    }

    [System.Runtime.InteropServices.DllImport("user32.dll")]
    extern static bool DestroyIcon(IntPtr handle);

推荐答案

使用

var dragImage = new Bitmap((Bitmap)picBox.Image, picBox.Size);

代替

var dragImage = (Bitmap)picBox.Image;

(也许稍后会在临时映像上调用 Dispose，但如果您不这样做，GC 会处理它)

(and maybe call Dispose on the temporary image later, but the GC will deal with it if you don't)

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