asp.net 簡單驗證碼驗證實現(xiàn)代碼

private int codeLen = 4;//驗證碼長度 
private int fineness = 85;//圖片清晰度 
private int imgWidth = 48;//圖片寬度 
private int imgHeight = 24;//圖片高度 
private string fontFamily = "Times New Roman";//字體名稱 
private int fontSize = 14;//字體大小 
private int fontStyle = 0;//字體樣式 
private int posX = 0;//繪制起始坐標X 
private int posY = 0;//繪制坐標Y 
private string CreateValidateCode() //生成驗證碼 
{ 
string validateCode = ""; 
Random random = new Random();// 隨機數(shù)對象 
for (int i = 0; i < codeLen; i++)//循環(huán)生成每位數(shù)值 
{ 
int n = random.Next(10);//數(shù)字 
validateCode += n.ToString(); 
} 
Session["vcode"] = validateCode;//保存驗證碼 
return validateCode;// 返回驗證碼 
} 
private void DisturbBitmap(Bitmap bitmap)//圖像背景 
{ 
Random random = new Random();//通過隨機數(shù)生成 
for (int i = 0; i < bitmap.Width; i++)//通過循環(huán)嵌套，逐個像素點生成 
{ 
for (int j = 0; j < bitmap.Height; j++) 
{ 
if (random.Next(90) <= this.fineness) 
bitmap.SetPixel(i,j,Color.LightGray); 
} 
} 
} 
private void DrewValidateCode(Bitmap bitmap,string validateCode)//繪制驗證碼圖像 
{ 
Graphics g = Graphics.FromImage(bitmap);//獲取繪制器對象 
Font font = new Font(fontFamily,fontSize,FontStyle.Bold);//設置繪制字體 
g.DrawString(validateCode,font,Brushes.Black,posX,posY);//繪制驗證碼圖像 
} 
 
最后就是調(diào)用了 
 代碼如下:

protected void Page_Load(object sender, EventArgs e) 
{ 
string validateCode = CreateValidateCode();//生成驗證碼 
Bitmap bitmap = new Bitmap(imgWidth,imgHeight);//生成Bitmap圖像 
DisturbBitmap(bitmap); //圖像背景 
DrewValidateCode(bitmap,validateCode);//繪制驗證碼圖像 
bitmap.Save(Response.OutputStream,ImageFormat.Gif);//保存圖像，等待