在胜利形式上绘画的drawbitmap

Question

我有一个Windows窗体，我需要画一些线条和矩形来显示窗体上的形状。 我想捕获这些显示的绘画，将它们存储在数据库中 我用于捕获的方法是：

internal void CapturePartition()
    {
        Bitmap PartitionImage = new Bitmap(lblRight.Location.X+lblRight.Width, lblPartitionWidth.Location.Y+lblPartitionWidth.Height);
        this.DrawToBitmap(PartitionImage, new Rectangle(lblPartitionName.Location.X, lblPartitionName.Location.Y, lblRight.Location.X + lblRight.Width, lblPartitionWidth.Location.Y + lblPartitionWidth.Height));
        //PartitionImage.Save(Globals.ProjectName + "1", System.Drawing.Imaging.ImageFormat.Jpeg);
        Bitmap ResizedPartitionImage = new Bitmap(PartitionImage, new Size(200, 200));
        MemoryStream MS = new MemoryStream();
        ResizedPartitionImage.Save(MS, System.Drawing.Imaging.ImageFormat.Jpeg);
        PartiionBinary = new System.Data.Linq.Binary(MS.GetBuffer());
    }

但捕获后的图像为空，只显示表格背景 怎么了？