如何获得一个DataGridView行作为光标图标的位图？

Question

I'm trying to get a DataGridViews row as Bitmap to use it as a cursors icon. Sadly the DataGridViewRow object has no DrawToBitmap method.

I managed to get the bound of the row (RowRect) and get a Bitmap of the whole DataGridView (bmp). I think I next need to cut the row from the bitmap, but I have no idea how to do that.

Here is my starting code:

private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
{
    if (dataGridView1.SelectedRows.Count == 1)
    {
        if (e.Button == MouseButtons.Left)
        {
            rw = dataGridView1.SelectedRows[0];
            Rectangle RowRect = dataGridView1.GetRowDisplayRectangle(rw.Index, true);
            Bitmap bmp = new Bitmap(RowRect.Width, RowRect.Height);
            dataGridView1.DrawToBitmap(bmp, new Rectangle(Point.Empty, bmp.Size));
            Cursor cur = new Cursor(bmp.GetHicon());
            Cursor.Current = cur;
            rowIndexFromMouseDown = dataGridView1.SelectedRows[0].Index;
            dataGridView1.DoDragDrop(rw, DragDropEffects.Move);
        }
    }
}

Answer 1

You need to grab the whole clientarea content first (your bitmap is too small!), then cut out the row rectangle. Also make sure to dispose of the created resources!

This should work:

private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
{

    if (dataGridView1.SelectedRows.Count == 1)
    {
        if (e.Button == MouseButtons.Left)
        {
            Size dgvSz = dataGridView1.ClientSize;
            int rw = dataGridView1.SelectedRows[0].Index;
            Rectangle RowRect = dataGridView1.GetRowDisplayRectangle(rw, true);
            using (Bitmap bmpDgv = new Bitmap(dgvSz.Width, dgvSz.Height))
            using (Bitmap bmpRow = new Bitmap(RowRect.Width, RowRect.Height))
            {
                dataGridView1.DrawToBitmap(bmpDgv , new Rectangle(Point.Empty, dgvSz));
                using ( Graphics G = Graphics.FromImage(bmpRow ))
                    G.DrawImage(bmpDgv , new Rectangle(Point.Empty, 
                                RowRect.Size), RowRect, GraphicsUnit.Pixel);
                Cursor.Current.Dispose();   // not quite sure if this is needed
                Cursor cur = new Cursor(bmpRow .GetHicon());
                Cursor.Current = cur;
                rowIndexFromMouseDown = dataGridView1.SelectedRows[0].Index;
                dataGridView1.DoDragDrop(rw, DragDropEffects.Move);
            }
        }
    }
}