添加拖放后CellDoubleClick事件不起作用

是的,那不行。调用DoDragDrop()将鼠标控制权转换为WindowsD+D逻辑,这将干扰正常的鼠标处理。您需要延迟启动D+D,直到看到用户实际在拖动。这应该能解决问题:

    Point dragStart;

    private void dataGridView1_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e) {
        if (e.Button == MouseButtons.Left) dragStart = e.Location;
    }

    private void dataGridView1_CellMouseMove(object sender, DataGridViewCellMouseEventArgs e) {
        if (e.Button == MouseButtons.Left) {
            var min = SystemInformation.DoubleClickSize;
            if (Math.Abs(e.X - dragStart.X) >= min.Width ||
                Math.Abs(e.Y - dragStart.Y) >= min.Height) {
                // Call DoDragDrop
                //...
            }
        }
    }