运行效果如图
用法如下:
/// <summary> /// 显示验证码 /// </summary> /// <returns> 验证码 </returns> private void GetVerifyCode() { VerifyCodeImage verifyCodeImage = new VerifyCodeImage(); // 取随机码 string code = verifyCodeImage.CreateVerifyCode().ToUpper(); // 输出图片 this .picVerifyCode.Image = verifyCodeImage.CreateImage(code, 3 ); this .picVerifyCode.Tag = code; }
private void picVerifyCode_DoubleClick( object sender, EventArgs e) { this .GetVerifyCode(); // this.txtVerifyCode.Clear(); this .txtVerifyCode.SelectAll(); this .txtVerifyCode.Focus(); }
源码如下:
// ----------------------------------------------------------------- // All Rights Reserved , Copyright (C) 2011 , Hairihan TECH, Ltd. // ----------------------------------------------------------------- using System; using System.Drawing; using System.Web; namespace DotNet.Utilities{ public class VerifyCodeImage { public VerifyCodeImage() { } #region 验证码长度(默认4个验证码的长度) int length = 4 ; public int Length { get { return length; } set { length = value; } } #endregion #region 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改) int fontSize = 50 ; public int FontSize { get { return fontSize; } set { fontSize = value; } } #endregion #region 边框补(默认1像素) int padding = 2 ; public int Padding { get { return padding; } set { padding = value; } } #endregion #region 是否输出燥点(默认不输出) bool chaos = true ; public bool Chaos { get { return chaos; } set { chaos = value; } } #endregion #region 输出燥点的颜色(默认灰色) Color chaosColor = Color.LightGray; public Color ChaosColor { get { return chaosColor; } set { chaosColor = value; } } #endregion #region 自定义背景色(默认白色) Color backgroundColor = Color.White; public Color BackgroundColor { get { return backgroundColor; } set { backgroundColor = value; } } #endregion #region 自定义随机颜色数组 Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple }; public Color[] Colors { get { return colors; } set { colors = value; } } #endregion #region 自定义字体数组 string [] fonts = { " Arial " , " Georgia " }; public string [] Fonts { get { return fonts; } set { fonts = value; } } #endregion #region 自定义随机码字符串序列(使用逗号分隔) // 去除 0,1,i,l,o,I,L,O string codeSerial = " 2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,J,K,M,N,P,Q,R,S,T,U,V,W,X,Y,Z " ; public string CodeSerial { get { return codeSerial; } set { codeSerial = value; } } #endregion #region 产生波形滤镜效果 // private const double PI = 3.1415926535897932384626433832795; private const double PI2 = 6.283185307179586476925286766559 ; /// <summary> /// 正弦曲线Wave扭曲图片（Edit By 51aspx.com） /// </summary> /// <param name="srcBmp"> 图片路径 </param> /// <param name="bXDir"> 如果扭曲则选择为True </param> /// <param name="nMultValue"> 波形的幅度倍数，越大扭曲的程度越高，一般为3 </param> /// <param name="dPhase"> 波形的起始相位，取值区间[0-2*PI) </param> /// <returns></returns> public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase) { System.Drawing.Bitmap bitmap = new Bitmap(srcBmp.Width, srcBmp.Height); // 将位图背景填充为白色 System.Drawing.Graphics graphics = System.Drawing.Graphics.FromImage(bitmap); graphics.FillRectangle( new SolidBrush(System.Drawing.Color.White), 0 , 0 , bitmap.Width, bitmap.Height); graphics.Dispose(); double dBaseAxisLen = bXDir ? ( double )bitmap.Height : ( double )bitmap.Width; for ( int i = 0 ; i < bitmap.Width; i ++ ) { for ( int j = 0 ; j < bitmap.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 < bitmap.Width && nOldY >= 0 && nOldY < bitmap.Height) { bitmap.SetPixel(nOldX, nOldY, color); } } } return bitmap; } #endregion #region 生成校验码图片 public Bitmap CreateImage( string code, double multValue) { int fSize = FontSize; int fWidth = fSize + Padding; int p_w_picpathWidth = ( int )(code.Length * fWidth) + 4 + Padding * 2 ; int p_w_picpathHeight = fSize * 2 + Padding; System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(p_w_picpathWidth, p_w_picpathHeight); Graphics graphics = Graphics.FromImage(bitmap); graphics.Clear(BackgroundColor); Random rand = new Random(); // 给背景添加随机生成的燥点 if ( this .Chaos) { Pen pen = new Pen(ChaosColor, 0 ); int c = Length * 10 ; for ( int i = 0 ; i < c; i ++ ) { int x = rand.Next(bitmap.Width); int y = rand.Next(bitmap.Height); graphics.DrawRectangle(pen, x, y, 1 , 1 ); } } int left = 0 , top = 0 , top1 = 1 , top2 = 1 ; int n1 = (p_w_picpathHeight - FontSize - Padding * 2 ); int n2 = n1 / 4 ; top1 = n2; top2 = n2 * 2 ; Font font; Brush brush; int cindex, findex; // 随机字体和颜色的验证码字符 for ( int i = 0 ; i < code.Length; i ++ ) { cindex = rand.Next(Colors.Length - 1 ); findex = rand.Next(Fonts.Length - 1 ); font = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold); brush = new System.Drawing.SolidBrush(Colors[cindex]); if (i % 2 == 1 ) { top = top2; } else { top = top1; } left = i * fWidth; graphics.DrawString(code.Substring(i, 1 ), font, brush, left, top); } // 画一个边框 边框颜色为Color.Gainsboro graphics.DrawRectangle( new Pen(Color.Gainsboro, 0 ), 0 , 0 , bitmap.Width - 1 , bitmap.Height - 1 ); graphics.Dispose(); // 产生波形 bitmap = TwistImage(bitmap, true , multValue, 4 ); return bitmap; } #endregion #region 生成随机字符码 public string CreateVerifyCode( int codeLength) { if (codeLength == 0 ) { codeLength = Length; } string [] arr = CodeSerial.Split( ' , ' ); string code = "" ; int randValue = - 1 ; Random random = new Random( unchecked (( int )DateTime.Now.Ticks)); for ( int i = 0 ; i < codeLength; i ++ ) { randValue = random.Next( 0 , arr.Length - 1 ); code += arr[randValue]; } return code; } public string CreateVerifyCode() { return CreateVerifyCode( 0 ); } #endregion #region 将创建好的图片输出到页面 /// <summary> /// 将创建好的图片输出到页面 /// </summary> /// <param name="code"> 验证码 </param> /// <param name="multValue"> 扭曲度(越大越扭曲) </param> /// <param name="httpContext"> 上下文 </param> public void CreateImageOnPage( string code, double multValue, HttpContext httpContext) { System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(); Bitmap bitmap = this .CreateImage(code, multValue); bitmap.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Jpeg); httpContext.Response.ClearContent(); httpContext.Response.ContentType = " p_w_picpath/Jpeg " ; httpContext.Response.BinaryWrite(memoryStream.GetBuffer()); memoryStream.Close(); memoryStream = null ; bitmap.Dispose(); bitmap = null ; } #endregion }}