Question

用C#在window应用程序上怎么写验证码？

Answer 1

Bitmap img = new Bitmap(80,35);
Graphics g = Graphics.FromImage(img);
g.Clear(Color.White);
g.DrawRectangle(new Pen(Color.Red,2), new Rectangle(0,0,img.Width,img.Height));

for (int i = 0; i < 50; i++)
{
int x = new Random().Next(img.Width);
int y = new Random().Next(img.Height);
img.SetPixel(x, y,Color.Blue);
}

for (int i = 0; i < 2; i++)
{
int x = new Random().Next(100);
int y = new Random().Next(100);
int x1 = new Random().Next(100);
int y1 = new Random().Next(100);
g.DrawLine(new Pen(Color.Silver),new Point(x,y),new Point(x1,y1));
}

string code = "";
string pp = "abcdefghijklmnopqrstuvwxyz1234567890";
for (int i = 0; i < 4; i++)
{
code+=pp[new Random().Next(pp.Length)];
}
g.DrawString(code,new Font("宋体",20),Brushes.Black,new PointF(1,1));

pictureBox1.Image = img;

Answer 2

C#有一个专门绘制图片的类呀 Graphics 这个类吧 随机生成要验证的数字然后绘制成一张图片 将图片显示到一个图片控件上