c# - 面板中的图形故障

Question

我正在尝试将基本形状绘制到我表单的面板上。到目前为止没有任何反应，我不知道为什么。在我的表单的构造函数中调用此方法。

private void doGraphics()
    {
        Pen p = new Pen(Color.Black);//draws wire frame Shapes
        SolidBrush sb = new SolidBrush(Color.Yellow);//draws filled Shapes
        Graphics g = panel1.CreateGraphics();


        Point[] pointArray = { new Point(100, 20), new Point(100, 0), new Point(120, 0), new Point(120, 20) };
        g.FillPolygon(sb, pointArray);
        g.DrawPolygon(p, pointArray);
    }

任何建议都会很棒!

Answer 1

需要注册面板的Paint事件，使用自带参数的图形对象:

在构造函数中:

panel1.Paint += new PaintEventHandler(panel1_Paint);

处理程序本身:

void panel1_Paint(object sender, PaintEventArgs e) {
{
        Pen p = new Pen(Color.Black);//draws wire frame Shapes
        SolidBrush sb = new SolidBrush(Color.Yellow);//draws filled Shapes
        Graphics g = e.Graphics; // From Arguments


        Point[] pointArray = { new Point(100, 20), new Point(100, 0), new Point(120, 0), new Point(120, 20) };
        g.FillPolygon(sb, pointArray);
        g.DrawPolygon(p, pointArray);
}