随机图片生成器制作方法分享

  

复制代码 代码如下:

  /// <summary>

  /// PicHandler1 的摘要说明

  /// </summary>

  public class PicHandler1 : IHttpHandler, IRequiresSessionState

  {

  private string mCheckNo = string.Empty;

  protected ImgBuilder _ImgBuilder = new ImgBuilder();

  protected VryImgGen _ImgBuilderNew = new VryImgGen();

  private string _text = string.Empty;

  private string _font = "宋体";

  private int _fontSize = 8;

  private int _padding = 2;

  public void ProcessRequest(HttpContext context)

  {

  mCheckNo = DisCheckNo();

  context.Session["CheckCode"] = mCheckNo;

  this._ImgBuilder.FontSize = this._fontSize;

  this._ImgBuilder.Padding = this._padding;

  if (!string.IsNullOrEmpty(this._font))

  {

  this._ImgBuilder.Fonts = new string[] { this._font };

  }

  this._ImgBuilderNew.ChaosWight = 40;

  this._ImgBuilderNew.FontSize = 25;

  this._ImgBuilderNew.Padding = 3;

  System.Drawing.Bitmap image =

  this._ImgBuilderNew.CreateImage(mCheckNo);

  System.IO.MemoryStream ms = new System.IO.MemoryStream();

  image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

  context.Response.ClearContent();

  context.Response.ContentType = "image/Jpeg";

  context.Response.BinaryWrite(ms.ToArray());

  context.Session["CheckCode"] = mCheckNo.ToString(); //如果没有实现IRequiresSessionState,则这里会出错,也无法生成图片

  context.Response.End();

  }

  //验证码生成

  protected string DisCheckNo()

  {

  string hash = HashCode.GetNext();

  string CheckNo = string.Empty;

  Random rd = new Random(DateTime.Now.Millisecond);

  for (int i = 0; i < 6; i++)

  {

  CheckNo += hash.Substring(rd.Next(1, hash.Length - 1), 1);

  }

  CheckNo = CheckNo.Replace("0", rd.Next(1, 9).ToString());

  CheckNo = CheckNo.Replace("o", rd.Next(1, 9).ToString());

  CheckNo = CheckNo.Replace("O", rd.Next(1, 9).ToString());

  return CheckNo;

  }

  public bool IsReusable

  {

  get

  {

  return false;

  }

  }

  }

  调用的类

  

复制代码 代码如下:

  using System;

  using System.Drawing;

  using System.Text;

  /// <summary>

  /// VryImgGen 的摘要说明

  /// </summary>

  public class VryImgGen

  {

  public static string ChineseChars = String.Empty;

  /// <summary>

  /// 英文与数字串

  /// </summary>

  protected static readonly string EnglishOrNumChars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

  public VryImgGen()

  {

  rnd = new Random(unchecked((int)DateTime.Now.Ticks));

  }

  /// <summary>

  /// 全局随机数生成器

  /// </summary>

  private Random rnd;

  int length = 5;

  /// <summary>

  /// 验证码长度(默认6个验证码的长度)

  /// </summary>

  public int Length

  {

  get { return length; }

  set { length = value; }

  }

  int fontSize = 20;

  /// <summary>

  /// 验证码字体大小(为了显示扭曲效果,默认30像素,可以自行修改)

  /// </summary>

  public int FontSize

  {

  get { return fontSize; }

  set { fontSize = value; }

  }

  int padding = 4;

  /// <summary>

  /// 边框补(默认4像素)

  /// </summary>

  public int Padding

  {

  get { return padding; }

  set { padding = value; }

  }

  bool chaos = true;

  /// <summary>

  /// 是否输出燥点(默认输出)

  /// </summary>

  public bool Chaos

  {

  get { return chaos; }

  set { chaos = value; }

  }

  Color chaosColor = Color.LightGray;

  /// <summary>

  /// 输出燥点的颜色(默认灰色)

  /// </summary>

  public Color ChaosColor

  {

  get { return chaosColor; }

  set { chaosColor = value; }

  }

  int chaosWight = 1;

  /// <summary>

  /// 输出燥点的浓度

  /// </summary>

  public int ChaosWight

  {

  get { return chaosWight; }

  set { chaosWight = value; }

  }

  Color backgroundColor = Color.White;

  /// <summary>

  /// 自定义背景色(默认白色)

  /// </summary>

  public Color BackgroundColor

  {

  get { return backgroundColor; }

  set { backgroundColor = value; }

  }

  Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };

  /// <summary>

  /// 自定义随机颜色数组

  /// </summary>

  public Color[] Colors

  {

  get { return colors; }

  set { colors = value; }

  }

  string[] fonts = { "Arial", "Georgia" };

  /// <summary>

  /// 自定义字体数组

  /// </summary>

  public string[] Fonts

  {

  get { return fonts; }

  set { fonts = value; }

  }

  #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 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

  /// <summary>

  /// 生成校验码图片

  /// </summary>

  /// <param name="code">验证码</param>

  /// <returns></returns>

  public Bitmap CreateImage(string code)

  {

  int fSize = FontSize;

  int fWidth = fSize + Padding;

  int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2;

  int imageHeight = fSize * 2 + Padding * 2;

  System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth - 10, imageHeight - 10);

  Graphics g = Graphics.FromImage(image);

  g.Clear(BackgroundColor);

  //给背景添加随机生成的燥点

  if (this.Chaos)

  {

  Pen pen = new Pen(ChaosColor, 0);

  int c = ChaosWight * 10;

  for (int i = 0; i < c; i++)

  {

  int x = rnd.Next(image.Width);

  int y = rnd.Next(image.Height);

  g.DrawRectangle(pen, x, y, 1, 1);

  }

  }

  int left = 0, top = 0, top1 = 1, top2 = 1;

  int n1 = (imageHeight - FontSize - Padding * 2);

  int n2 = n1 / 4;

  top1 = n2;

  top2 = n2 * 2;

  Font f;

  Brush b;

  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 = rnd.Next(Colors.Length - 1);

  findex = rnd.Next(Fonts.Length - 1);

  f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);

  b = new System.Drawing.SolidBrush(Colors[cindex]);

  if (i % 2 == 1)

  {

  top = top2;

  }

  else

  {

  top = top1;

  }

  left = i * fWidth;

  g.DrawString(code.Substring(i, 1), f, b, left, top);

  }

  //画一个边框 边框颜色为Color.Gainsboro

  g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);

  g.Dispose();

  //产生波形(Add By 51aspx.com)

  image = TwistImage(image, true, 8, 4);

  return image;

  }

  /// <summary>

  /// 生成随机字符码

  /// </summary>

  /// <param name="codeLen">字符串长度</param>

  /// <param name="zhCharsCount">中文字符数</param>

  /// <returns></returns>

  public string CreateVerifyCode(int codeLen, int zhCharsCount)

  {

  char[] chs = new char[codeLen];

  int index;

  for (int i = 0; i < zhCharsCount; i++)

  {

  index = rnd.Next(0, codeLen);

  if (chs[index] == '\0')

  chs[index] = CreateZhChar();

  else

  --i;

  }

  for (int i = 0; i < codeLen; i++)

  {

  if (chs[i] == '\0')

  chs[i] = CreateEnOrNumChar();

  }

  return new string(chs, 0, chs.Length);

  }

  /// <summary>

  /// 生成默认长度5的随机字符码

  /// </summary>

  /// <returns></returns>

  public string CreateVerifyCode()

  {

  return CreateVerifyCode(Length, 0);

  }

  /// <summary>

  /// 生成英文或数字字符

  /// </summary>

  /// <returns></returns>

  protected char CreateEnOrNumChar()

  {

  return EnglishOrNumChars[rnd.Next(0, EnglishOrNumChars.Length)];

  }

  /// <summary>

  /// 生成汉字字符

  /// </summary>

  /// <returns></returns>

  protected char CreateZhChar()

  {

  //若提供了汉字集,查询汉字集选取汉字

  if (ChineseChars.Length > 0)

  {

  return ChineseChars[rnd.Next(0, ChineseChars.Length)];

  }

  //若没有提供汉字集,则根据《GB2312简体中文编码表》编码规则构造汉字

  else

  {

  byte[] bytes = new byte[2];

  //第一个字节值在0xb0, 0xf7之间

  bytes[0] = (byte)rnd.Next(0xb0, 0xf8);

  //第二个字节值在0xa1, 0xfe之间

  bytes[1] = (byte)rnd.Next(0xa1, 0xff);

  //根据汉字编码的字节数组解码出中文汉字

  string str1 = Encoding.GetEncoding("gb2312").GetString(bytes);

  return str1[0];

  }

  }

  }