winform如何实现拖动过程中改变光标样式？

就是DragEnter事件：

private void Form1_DragEnter(object sender, DragEventArgs e)
{
        Cursor.Current = Cursors.SizeAll;
 }


private void TextBox1_DragEnter(object sender, DragEventArgs e)
 {
     Cursor.Current = Cursors.SizeAll;
 }

但是做出来的效果依然是：

我想要的效果是：

请问怎么实现？

private void textBox1_DragEnter(object sender, DragEventArgs e)
{
    if (e.Data.GetDataPresent(DataFormats.FileDrop))
        e.Effect = DragDropEffects.All | DragDropEffects.Scroll;
    else
        e.Effect = DragDropEffects.Move | DragDropEffects.Scroll;
}

private void textBox1_DragDrop(object sender, DragEventArgs e)
{
    if (e.Data.GetDataPresent(DataFormats.FileDrop))
    {
        string s = "";
        string[] files = (string[])e.Data.GetData(DataFormats.FileDrop);
        if (files.Length > 0)
        {
            foreach (var item in files)
            {
                s += item + "\r\n";
            }
            textBox1.Text = s;
        }
    }
}