如何在C＃中的面板内绘制一个矩形？

Question

I want to draw a rectangle and I want to give position it with respect to the panel bottom.

    public void populateTable(int x, int y)
    {
        using (Graphics g = this.CreateGraphics())
        {
            Brush b = new SolidBrush(Color.Red);
            g.FillRectangle(b, x, y, 100, 40);
        }

    }

When I execute the code above, the rectangle is created successfully. But it's positioned with respect to form, not the panel. If I put x=10, y=10, then it's shown in the upper left corner of the form. But I want to show it in the bottom where I put a panel.

Answer 1

this.CreateGraphics() creates a Graphics object for this , which is the enclosing class - the form in this case.

You should try panel1.CreateGraphics() instead.

However, I would recommend not using CreateGraphics at all. It's better to handle OnPaint , so that your graphics gets redrawn when the form is redrawn (minimized then maximized, etc).