C#生成验证码

using System; using System.Collections; using System.ComponentModel; using System.Data; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.Web; using System.Web.SessionState; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; using System.IO; namespace Shop { /// <summary> /// Summary description for ValidateCode. /// </summary> public class ValidateCode : System.Web.UI.Page { /// <summary> /// Validation Code generated fromt these charaters. /// Note: l,L 1(number), o, O, 0(number) are removed /// </summary> private const string strValidateCodeBound = "abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNPQRSTUVWXYZ23456789"; private static string[] Fonts = new string[] { "Helvetica", "Geneva", "sans-serif", "Verdana", "Times New Roman", "Courier New", "Arial" }; #region Web Form Designer generated code override protected void OnInit(EventArgs e) { // // CODEGEN: This call is required by the ASP.NET Web Form Designer. // InitializeComponent(); base.OnInit(e); } /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load); } #endregion /// <summary> /// event handler of page load /// </summary> private void Page_Load(object sender, System.EventArgs e) { if(!IsPostBack) { string str_ValidateCode = GetRandomString(6); Session["ValidateCode"] = str_ValidateCode; CreateImage(str_ValidateCode); } } /// <summary> /// Generate random string /// </summary> private string GetRandomString(int int_NumberLength) { string valString = string.Empty; Random theRandomNumber = new Random((int)DateTime.Now.Ticks); for (int int_index = 0; int_index < int_NumberLength; int_index++) valString += strValidateCodeBound[theRandomNumber.Next(strValidateCodeBound.Length - 1)].ToString(); return valString; } /// <summary> /// Generate random Color /// </summary> private Color GetRandomColor() { Random RandomNum_First = new Random((int)DateTime.Now.Ticks); System.Threading.Thread.Sleep(RandomNum_First.Next(50)); Random RandomNum_Sencond = new Random((int)DateTime.Now.Ticks); int int_Red = RandomNum_First.Next(256); int int_Green = RandomNum_Sencond.Next(256); int int_Blue = (int_Red + int_Green > 400) ? 0 : 400 - int_Red - int_Green; int_Blue = (int_Blue > 255) ? 255 : int_Blue; return Color.FromArgb(int_Red, int_Green, int_Blue); } /// <summary> /// Create Validation Code Image /// </summary> private void CreateImage(string str_ValidateCode) { int int_ImageWidth = str_ValidateCode.Length * 22; Random newRandom = new Random(); Bitmap theBitmap = new Bitmap(int_ImageWidth + 6 , 38); Graphics theGraphics = Graphics.FromImage(theBitmap); theGraphics.Clear(Color.White); drawLine(theGraphics, theBitmap, newRandom); theGraphics.DrawRectangle(new Pen(Color.LightGray, 1), 0, 0, theBitmap.Width - 1, theBitmap.Height -1 ); for (int int_index = 0; int_index < str_ValidateCode.Length; int_index++) { Matrix X = new Matrix(); X.Shear((float)newRandom.Next(0,300)/1000 - 0.25f, (float)newRandom.Next(0,100)/1000 - 0.05f); theGraphics.Transform = X; string str_char = str_ValidateCode.Substring(int_index, 1); System.Drawing.Drawing2D.LinearGradientBrush newBrush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, theBitmap.Width, theBitmap.Height), Color.Blue, Color.DarkRed, 1.2f, true); Point thePos = new Point(int_index * 21 + 1 + newRandom.Next(3), 1 + newRandom.Next(13)); Font theFont = new Font(Fonts[newRandom.Next(Fonts.Length -1)], newRandom.Next(14,18), FontStyle.Bold); theGraphics.DrawString(str_char, theFont, newBrush, thePos); } drawPoint(theBitmap, newRandom); MemoryStream ms = new MemoryStream(); theBitmap.Save(ms, ImageFormat.Png); Response.ClearContent(); Response.ContentType = "image/Png"; Response.BinaryWrite(ms.ToArray()); theGraphics.Dispose(); theBitmap.Dispose(); Response.End(); } /// <summary> /// Draw Line for noise /// </summary> private void drawLine(Graphics gfc,Bitmap img, Random ran) { for (int i = 0; i < 10; i++) { int x1 = ran.Next(img.Width); int y1 = ran.Next(img.Height); int x2 = ran.Next(img.Width); int y2 = ran.Next(img.Height); gfc.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2); } } /// <summary> /// Draw Point for noise /// </summary> private void drawPoint(Bitmap img, Random ran) { for (int i = 0; i < 30; i++) { int x = ran.Next(img.Width); int y = ran.Next(img.Height); img.SetPixel(x,y,Color.FromArgb(ran.Next())); } } } }