Winform之GDI作图验证码

1　　　　　　　　Random random = new Random();
2             //产生5个随机字符串
3             str = null;
4             for (int i = 0; i < 5; i++)
5             {
6                 int j = random.Next(64, 90);
7                 str = str + (char)j;
8             }

 1             //创建图片
 2             Bitmap bmp = new Bitmap(120,30);
 3             //创建GDI对象
 4             Graphics g = Graphics.FromImage(bmp);
 5             //循环画字符串
 6             for (int i = 0; i < str.Length; i++)
 7             {
 8                 Point p = new Point(i*20,0);
 9                 //随机字体
10                 string[] fonts = { "宋体", "黑体", "微软雅黑", "隶属", "仿宋", };
11                 //随机颜色
12                 Color[] colors = { Color.Red, Color.Aquamarine, Color.Blue, Color.Yellow, Color.YellowGreen };
13                 //画字符串
14                 g.DrawString(str[i].ToString(), new Font(fonts[random.Next(0, fonts.Length)], 20, FontStyle.Bold), new SolidBrush(colors[random.Next(0, colors.Length)]), p);
15             }                

1 　　　　　　　for (int i = 0; i < 20; i++)
2             {
3                 Point p1 = new Point(random.Next(0, bmp.Width), random.Next(0, bmp.Height));
4                 Point p2 = new Point(random.Next(0, bmp.Width), random.Next(0, bmp.Height));
5                 g.DrawLine(new Pen(Color.Green), p1, p2);
6             }

1            //画像素点
2             for (int i = 0; i < 500; i++)
3             {
4                 Point p = new Point(random.Next(0, bmp.Width), random.Next(0, bmp.Height));
5                 bmp.SetPixel(p.X, p.Y, Color.Black);
6             }