我如何绘制pictureBox1中心点+10使用随机？

Question

我这个简单的代码，每次我按一下按钮其在位置100,100

绘制在pictureBox1点，但我想首先计算（我需要学习如何做到这一点）的pictureBox1的中心。

然后我想使用随机所以每次我点击按钮，它就会从pictureBox1中心位置+ 10

private void button5_MouseClick(object sender, MouseEventArgs e) 
     { 
      Random rnd = new Random(); 
      drawPoint(100, 100); 
     } 

     public void drawPoint(int x, int y) 
     { 
     Graphics g = Graphics.FromHwnd(pictureBox1.Handle); 
     SolidBrush brush = new SolidBrush(Color.LimeGreen); 
     Point dPoint = new Point(x, (pictureBox1.Height - y)); 
     dPoint.X = dPoint.X - 2; 
     dPoint.Y = dPoint.Y - 2; 
     Rectangle rect = new Rectangle(dPoint, new Size(4, 4)); 
     g.FillRectangle(brush, rect); 
     g.Dispose(); 
     } 

Answer 1

试试这个randomaly画一个点。它会计算从中心随机偏移+ 10，-10

public partial class Form1 : Form 
    { 
     public Form1() 
     { 
      InitializeComponent(); 
     } 

     private void button1_Click(object sender, EventArgs e) 
     { 
      var halfX = pictureBox1.ClientRectangle.Width/2; 
      var halfY = pictureBox1.ClientRectangle.Height/2; 

      Random rnd = new Random(); 
      var offsetX = rnd.Next(-10, 10); 
      var offsetY = rnd.Next(-10, 10); 

      drawPoint(halfX + offsetX, halfY + offsetY); 
     } 

     public void drawPoint(int x, int y) 
     { 
      Graphics g = Graphics.FromHwnd(pictureBox1.Handle); 
      SolidBrush brush = new SolidBrush(Color.LimeGreen); 
      Point dPoint = new Point(x, (pictureBox1.Height - y)); 
      dPoint.X = dPoint.X - 2; 
      dPoint.Y = dPoint.Y - 2; 
      Rectangle rect = new Rectangle(dPoint, new Size(4, 4)); 
      g.FillRectangle(brush, rect); 
      g.Dispose(); 
     } 
    }