ASP.NET中一个简单的验证码生成程序,留着以后用!
protected void Page_Load(object sender, EventArgs e)
{
this.CreateCode(this.CreateStr());
Session["check_code"] = CreateStr();
}
protected string CreateStr()
{
string str = "";
Random random = new Random();
str = random.Next(1000,9999).ToString();
return str;
}
protected void CreateCode(string code)
{
if (code.Length == 0)
return;
Random random = new Random();
Bitmap map = new Bitmap(4*14,30);//定义一个宽度为4*13,高度为30像素的位图
Graphics g = Graphics.FromImage(map);
g.Clear(Color.White);
g.DrawRectangle(new Pen(Color.Gray), 0, 0, map.Width - 1, map.Height - 1);//进行描边
//...开始写字
Matrix matrix;//声明用来操作矩阵的类
LinearGradientBrush brush = new LinearGradientBrush(new Point(0, 0), new Point(map.Width, map.Height), Color.Red, Color.Green);
for (int j = 0; j < code.Length; j++)
{
string schar = code.Substring(j,1);
matrix = g.Transform;//获取当前绘图的世界坐标系。
float shearx = 0.0F;
float sheary = 0.0F;
matrix.Shear(shearx,sheary);
g.Transform = matrix;
g.DrawString(schar,new Font("黑体",14.0f,FontStyle.Bold),brush,new PointF(0.0f+(13.0f*j),random.Next(30-20)));
}
//画干扰线
int x1=random.Next(map.Width);
int y1=random.Next(map.Height);
int x2=random.Next(map.Width);
int y2=random.Next(map.Height);
g.DrawLine(new Pen(Color.Black),new Point(x1,y1),new Point(x2,y2));
//画干扰点
for(int i=0;i<10;i++)
{
map.SetPixel(random.Next(map.Width),random.Next(map.Height),Color.FromArgb(random.Next(255),random.Next(255),random.Next(255)));
}
Response.Clear();
MemoryStream stream=new MemoryStream();
map.Save(stream,ImageFormat.Gif);
Response.ContentType="image/Gif";
Response.BinaryWrite(stream.ToArray());
}