绘制矩形只需绘制 1 个点

Question

我写了一些代码来生成随机点并生成随机矩形。所有调试似乎都可以，但代码只绘制了 1 个矩形。查看我的代码并告诉我出了什么问题。private void btnRun_Click(object sender, EventArgs e){    Graphics g = pnlWarZone.CreateGraphics();    if (int.Parse(txtGenerationCount.Text) > 0)    {        RectangleF[] rects = new RectangleF[int.Parse(txtGenerationCount.Text)];        for (int i = 0; i < int.Parse(txtGenerationCount.Text); i++)        {            rects[i] = new RectangleF(GeneratePoint(),new SizeF(4,4));        }        g.FillRectangles(new SolidBrush(Color.Blue), rects);    }}更新：这是生成点的方法private Point GeneratePoint(){    Random r = new Random();    //return random.NextDouble() * (maxValue - minValue) + minValue;    var x =r.Next(_rectangles[0].X, _rectangles[0].Width);    var y =r.Next(_rectangles[0].Y, _rectangles[0].Height);    return new Point(x,y);}

Answer 1

您的代码很可能看起来像这样：

private Point GeneratePoint() {

  Random rnd = new Random();

  int x = rnd.Next(0, pnlWarZone.ClientSize.Width);

  int y = rnd.Next(0, pnlWarZone.ClientSize.Height);

  return new Point(x, y);

}

您要做的只是生成一个新的 Random 对象一次，然后始终重新使用该变量：

Random rnd = new Random();

private Point GeneratePoint() {      

  int x = rnd.Next(0, pnlWarZone.ClientSize.Width);

  int y = rnd.Next(0, pnlWarZone.ClientSize.Height);

  return new Point(x, y);

}