GDI+ 绘图一闪而过

Question

点击菜单后 生成图形，闪了一下就什么都没了，怎么个情况？Graphics dc = this.pnGrid.CreateGraphics();
            dc.TranslateTransform(this.pnGrid.AutoScrollPosition.X, this.pnGrid.AutoScrollPosition.Y); //文档到设备区的坐标变换
            this.pnGrid.AutoScrollMinSize = new Size(grdFileInfo.rowsNum, grdFileInfo.cloumnsNum);            Pen gridPen = new Pen(Color.Black, 1);
            for (int x = 0; x < grdFileInfo.cloumnsNum; x += 50)
            {
                for (int y = 0; y < grdFileInfo.rowsNum; y += 50)
                {
                    Point tempTop = new Point(x, y - 3);
                    Point tempBottom = new Point(x, y + 3);
                    Point tempLeft = new Point(x - 3, y);
                    Point tempRight = new Point(x + 3, y);                    dc.DrawLine(gridPen, tempTop, tempBottom);
                    dc.DrawLine(gridPen, tempLeft, tempRight);
                }
            }

Answer 1

界面上放一个picturebox，然后在picturebox上画就不会消失了