验证码类
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|
namespace QJW.VerifyCode { //用法: //public FileContentResult CreateValidate() //{ // ValidateCode vCode = new ValidateCode(); // string code = vCode.CreateValidateCode(5); // Session["ValidateCode"] = code; // byte[] bytes = vCode.CreateValidateGraphic(code); // return File(bytes, "image/JPEG"); //} public class ValidateCode { public ValidateCode() { } /// <summary> /// 验证码的最大长度 /// </summary> public int MaxLength { get { return 10; } } /// <summary> /// 验证码的最小长度 /// </summary> public int MinLength { get { return 1; } } /// <summary> /// 生成验证码 /// </summary> /// <param name="length">指定验证码的长度</param> /// <returns></returns> public string CreateValidateCode( int length) { int [] randMembers = new int [length]; int [] validateNums = new int [length]; string validateNumberStr = "" ; //生成起始序列值 int seekSeek = unchecked (( int )DateTime.Now.Ticks); Random seekRand = new Random(seekSeek); int beginSeek = ( int )seekRand.Next(0, Int32.MaxValue - length * 10000); int [] seeks = new int [length]; for ( int i = 0; i < length; i++) { beginSeek += 10000; seeks[i] = beginSeek; } //生成随机数字 for ( int i = 0; i < length; i++) { Random rand = new Random(seeks[i]); int pownum = 1 * ( int )Math.Pow(10, length); randMembers[i] = rand.Next(pownum, Int32.MaxValue); } //抽取随机数字 for ( int i = 0; i < length; i++) { string numStr = randMembers[i].ToString(); int numLength = numStr.Length; Random rand = new Random(); int numPosition = rand.Next(0, numLength - 1); validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1)); } //生成验证码 for ( int i = 0; i < length; i++) { validateNumberStr += validateNums[i].ToString(); } return validateNumberStr; } /// <summary> /// 创建验证码的图片 /// </summary> /// <param name="containsPage">要输出到的page对象</param> /// <param name="validateNum">验证码</param> public byte [] CreateValidateGraphic( string validateCode) { Bitmap image = new Bitmap(( int )Math.Ceiling(validateCode.Length * 12.0), 22); Graphics g = Graphics.FromImage(image); try { //生成随机生成器 Random random = new Random(); //清空图片背景色 g.Clear(Color.White); //画图片的干扰线 for ( int i = 0; i < 25; i++) { int x1 = random.Next(image.Width); int x2 = random.Next(image.Width); int y1 = random.Next(image.Height); int y2 = random.Next(image.Height); g.DrawLine( new Pen(Color.Silver), x1, y1, x2, y2); } Font font = new Font( "Arial" , 12, (FontStyle.Bold | FontStyle.Italic)); LinearGradientBrush brush = new LinearGradientBrush( new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true ); g.DrawString(validateCode, font, brush, 3, 2); //画图片的前景干扰点 for ( int i = 0; i < 100; i++) { int x = random.Next(image.Width); int y = random.Next(image.Height); image.SetPixel(x, y, Color.FromArgb(random.Next())); } //画图片的边框线 g.DrawRectangle( new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); //保存图片数据 MemoryStream stream = new MemoryStream(); image.Save(stream, ImageFormat.Jpeg); //输出图片流 return stream.ToArray(); } finally { g.Dispose(); image.Dispose(); } } /// <summary> /// 得到验证码图片的长度 /// </summary> /// <param name="validateNumLength">验证码的长度</param> /// <returns></returns> public static int GetImageWidth( int validateNumLength) { return ( int )(validateNumLength * 12.0); } /// <summary> /// 得到验证码的高度 /// </summary> /// <returns></returns> public static double GetImageHeight() { return 22.5; } } } |
使用方法
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public FileContentResult CreateValidate() { ValidateCode vCode = new ValidateCode(); string code = vCode.CreateValidateCode(5); Session[ "ValidateCode" ] = code; byte [] bytes = vCode.CreateValidateGraphic(code); return File(bytes, "image/JPEG" ); } |
HTML
<a href="javascript:;" onclick="reloadcode();"><img id="safecode" src="/common/CreateValidate" js" id="highlighter_38657">
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function
reloadcode() {
var
verify = document.getElementById(
'safecode'
);
verify.setAttribute(
'src'
,
'/common/CreateValidate?'
+ Math.random());
}