c# - 如何在带有图像的面板上绘制点

Question

我有一个名为 dPanel 的面板。我用名为 dImage 的图像设置该面板的背景图像。现在我想在面板上绘制点，换句话说，我想使用鼠标为面板着色。我希望能够将绘图和图像一起保存之后。我的代码执行此操作，但图片在绘图过程中亮起并且速度非常慢。这是我的代码:

 private void drawP_MouseDown(object sender, MouseEventArgs e)
    {
        if (!drawbool)
        {
            dStartPoint = e.Location;
            drawbool = true;
        }
        drawP.Invalidate();
    }
 private void drawP_MouseMove(object sender, MouseEventArgs e)
    {
        if (drawbool)
        {
            dStartPoint = e.Location;
            drawP.Invalidate();
        }
    }
 private void drawP_MouseUp(object sender, MouseEventArgs e)
    {
        if (drawbool)
        {
            drawbool = false;
        }
    }
  private void drawP_Paint_1(object sender, PaintEventArgs e)
    {
        if (drawbool)
        {
            int dStartX = dStartPoint.X;
            int dStartY = dStartPoint.Y;
            e.Graphics.DrawEllipse(dP, dStartX, dStartY, 2, 2);
            Bitmap dPPB = new Bitmap(drawP.Width, drawP.Height);
            drawP.DrawToBitmap(dPPB, new Rectangle(0, 0, drawP.Width, drawP.Height));
            drawP.BackgroundImage = (Image)dPPB;
        }
    }

Whani 是解决方案吗？提前致谢。

Answer 1

看看这个关于在面板上绘图的好例子:Painting on a Panel .

稍后您可以通过调用面板的方法 DrawToBitmap 来保存您的绘图。