mvc实现图片验证码功能
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2022-03-21 14:05:30
mvc中实现图片验证码很简单,只需要创建一个 filecontentresult的方法,返回file就行
///
///...
mvc中实现图片验证码很简单,只需要创建一个 filecontentresult的方法,返回file就行
/// <summary> /// 创建一个文件方法 /// </summary> /// <returns></returns> public filecontentresult getcode() { //参数一:产生几个字符的验证码图片 参数二:验证码的形式(数字、字母、数字字母混合都有) validatecode validcode = new validatecode(5, validatecode.codetype.alphas); //将图片转换为二进制 memorystream ms =validcode.createcheckcodeimage() as memorystream; datecode = validcode.checkcode; //通过 checkcode获取当前的验证码 byte[] buffurpic = ms.toarray(); return file(buffurpic, "image/jpeg"); }
以下是生成验证码代码:
using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.drawing; using system.drawing.drawing2d; using system.io; namespace helper { public class validatecode { #region private fields private const double pi = 3.1415926535897932384626433832795; private const double pi2 = 6.283185307179586476925286766559; //private readonly int _wordslen = 4; private int _len; private codetype _codetype; private readonly single _jianju = (float)18.0; private readonly single _height = (float)24.0; private string _checkcode; #endregion #region public property public string checkcode { get { return _checkcode; } } #endregion #region constructors /// /// public constructors /// /// 验证码长度 /// 验证码类型:字母、数字、字母+ 数字 public validatecode(int len, codetype ctype) { this._len = len; this._codetype = ctype; } #endregion #region public field public enum codetype { words, numbers, characters, alphas } #endregion #region private methods public string generatenumbers() { string strout = ""; system.random random = new random(); for (int i = 0; i < _len; i++) { string num = convert.tostring(random.next(10000) % 10); strout += num; } return strout.trim(); } public string generatecharacters() { string strout = ""; system.random random = new random(); for (int i = 0; i < _len; i++) { string num = convert.tostring((char)(65 + random.next(10000) % 26)); strout += num; } return strout.trim(); } // public string generatealphas() { string strout = ""; string num = ""; system.random random = new random(); for (int i = 0; i < _len; i++) { if (random.next(500) % 2 == 0) { num = convert.tostring(random.next(10000) % 10); } else { num = convert.tostring((char)(65 + random.next(10000) % 26)); } strout += num; } return strout.trim(); } private system.drawing.bitmap twistimage(bitmap srcbmp, bool bxdir, double dmultvalue, double dphase) { system.drawing.bitmap destbmp = new bitmap(srcbmp.width, srcbmp.height); // 将位图背景填充为白色 system.drawing.graphics graph = system.drawing.graphics.fromimage(destbmp); graph.fillrectangle(new solidbrush(system.drawing.color.white), 0, 0, destbmp.width, destbmp.height); graph.dispose(); double dbaseaxislen = bxdir ? (double)destbmp.height : (double)destbmp.width; for (int i = 0; i < destbmp.width; i++) { for (int j = 0; j < destbmp.height; j++) { double dx = 0; dx = bxdir ? (pi2 * (double)j) / dbaseaxislen : (pi2 * (double)i) / dbaseaxislen; dx += dphase; double dy = math.sin(dx); // 取得当前点的颜色 int noldx = 0, noldy = 0; noldx = bxdir ? i + (int)(dy * dmultvalue) : i; noldy = bxdir ? j : j + (int)(dy * dmultvalue); system.drawing.color color = srcbmp.getpixel(i, j); if (noldx >= 0 && noldx < destbmp.width && noldy >= 0 && noldy < destbmp.height) { destbmp.setpixel(noldx, noldy, color); } } } return destbmp; } #endregion #region public methods public stream createcheckcodeimage() { string checkcode; switch (_codetype) { case codetype.alphas: checkcode = generatealphas(); break; case codetype.numbers: checkcode = generatenumbers(); break; case codetype.characters: checkcode = generatecharacters(); break; default: checkcode = generatealphas(); break; } this._checkcode = checkcode; memorystream ms = null; // if (checkcode == null || checkcode.trim() == string.empty) return null; bitmap image = new system.drawing.bitmap((int)math.ceiling((checkcode.length * _jianju)), (int)_height); graphics g = graphics.fromimage(image); try { random random = new random(); g.clear(color.white); // 画图片的背景噪音线 for (int i = 0; i < 18; 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.fromargb(random.next()), 1), x1, y1, x2, y2); } font font = new system.drawing.font("times new roman", 14, system.drawing.fontstyle.bold); lineargradientbrush brush = new lineargradientbrush(new rectangle(0, 0, image.width, image.height), color.blue, color.darkred, 1.2f, true); if (_codetype != codetype.words) { for (int i = 0; i < checkcode.length; i++) { g.drawstring(checkcode.substring(i, 1), font, brush, 2 + i * _jianju, 1); } } else { g.drawstring(checkcode, font, brush, 2, 2); } // 画图片的前景噪音点 for (int i = 0; i < 150; i++) { int x = random.next(image.width); int y = random.next(image.height); image.setpixel(x, y, color.fromargb(random.next())); } // 画图片的波形滤镜效果 if (_codetype != codetype.words) { image = twistimage(image, true, 3, 1); } // 画图片的边框线 g.drawrectangle(new pen(color.silver), 0, 0, image.width - 1, image.height - 1); ms = new system.io.memorystream(); image.save(ms, system.drawing.imaging.imageformat.gif); } finally { g.dispose(); image.dispose(); } return ms; } #endregion } }
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