asp.net 编写验证码
首先准备一个类来实现对验证码的绘制功能。
createcode.cs
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Drawing; 6 using System.IO; 7 using System.Configuration; 8 9 10 namespace LoginProject 11 { 12 public class createcode 13 { 14 static string yanzheng = ""; 15 int length = 4; 16 int fontsize = 25; 17 string[] fontfamily = { "Arial Narrow", "Baskerville Old Face", "Algerian" }; 18 Color[] colors = { Color.Red, Color.Pink, Color.Plum, Color.Purple, Color.PaleTurquoise, Color.Orchid };//颜色 19 string CodeValue = "1,2,3,4,5,6,7,8,9,0,a,b,c,d,e,f,g,h,l,i,j,k,m,n,o,p,q,r,s,t,w,q,y,u,x,z"; //值 20 int imgwidth = 100; //图片宽 21 int imgheight = 30; //图片高 22 public static string YanZheng 23 { 24 get { return yanzheng; } 25 } 26 public int GetLength 27 { 28 get { return length; } 29 set { length = value; } 30 } 31 public int FontSize 32 { 33 get { return fontsize; } 34 set { fontsize = value; } 35 } 36 public string[] FontFamily 37 { 38 get { return fontfamily; } 39 set { fontfamily = value; } 40 } 41 public Color[] GetColor 42 { 43 get { return colors; } 44 set { colors = value; } 45 } 46 public string codevalue 47 { 48 get { return CodeValue; } 49 set { CodeValue = value; } 50 } 51 public int ImaHeight 52 { 53 get { return imgheight; } 54 } 55 public int ImaWidth 56 { get { return imgwidth; } } 57 //产生随机字母 58 public string createvalue() 59 { 60 string val = ""; 61 string[] arr = codevalue.Split(‘,‘); 62 Random rand = new Random(); 63 for (int i = 0; i < GetLength; i++) 64 { 65 int strindex = rand.Next(0, arr.Length - 1); 66 val = val + arr[strindex]; 67 } 68 yanzheng = val; 69 return val; 70 } 71 //绘制背景图像 72 public void DrawImage(Bitmap map) 73 { 74 Random rand = new Random(); 75 for (int i = 0; i < map.Width; i++) 76 { 77 for (int j = 0; j < map.Height; j++) 78 { 79 if (rand.Next(60, 90) < 80) 80 { 81 map.SetPixel(i, j, Color.Beige); 82 } 83 } 84 } 85 } 86 //绘制验证码 87 public void DrawValue(string code, Bitmap bmap) 88 { 89 Random rand = new Random(); 90 Graphics g = Graphics.FromImage(bmap);//获取背景图片(获取绘制器对象) 91 92 System.Drawing.StringFormat sF = new StringFormat(); 93 sF.Alignment = StringAlignment.Center; 94 for (int i = 0; i < code.Length; i++) 95 { 96 System.Drawing.PointF point = new PointF(i * FontSize, 2); 97 string cellcode = code[i].ToString(); 98 Font F = new Font(FontFamily[rand.Next(0, 2)], FontSize, FontStyle.Italic); 99 g.DrawString(cellcode, F, Brushes.BlueViolet, point, sF); 100 } 101 } 102 //输出 103 public void Output(string code, HttpContext type) 104 { 105 // System.IO.MemoryStream ms = new MemoryStream(); 106 type.Response.ContentType = "image/jpeg"; 107 Bitmap bit = new Bitmap(ImaWidth,ImaHeight); 108 this.DrawImage(bit); 109 this.DrawValue(code, bit); 110 bit.Save(type.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); 111 //ms.Close(); 112 //ms = null; 113 bit.Dispose(); 114 bit = null; 115 } 116 } 117 }
然后准备一个页面来接收绘制出的验证码图片,如下
yanzhengma.aspx
1 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="yanzhengma.aspx.cs" Inherits="LoginProject.yanzhengma" %> 2 3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 4 5 <html xmlns="http://www.w3.org/1999/xhtml"> 6 <head runat="server"> 7 <title></title> 8 </head> 9 <body> 10 <form id="form1" runat="server"> 11 <div> 12 <asp:Image ID="imag" Width="100px" Height="50px" runat="server" ImageUrl="~/yanzhengma.aspx"/> 13 </div> 14 </form> 15 </body> 16 </html>
yanzhengma.aspx.cs
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Web.UI; 6 using System.Web.UI.WebControls; 7 8 namespace LoginProject 9 { 10 public partial class yanzhengma : System.Web.UI.Page 11 { 12 protected void Page_Load(object sender, EventArgs e) 13 { 14 createcode code = new createcode(); 15 string strcode = code.createvalue(); 16 code.Output(strcode, this.Context); 17 } 18 } 19 }
如果想实现“看不清换一张”的功能则需要在另外使用一个接收页面。这个页面就是你的登陆页面代码如下
1 <script type="text/javascript"> 2 function change() { 3 var img = document.getElementById("Image1"); 4 img.src = img.src + ‘?‘; 5 } 6 </script> 7 8 <td class="style1">验证码</td> 9 <td> 10 <asp:TextBox ID="yanzheng" runat="server" Width="150px" Height="25px"></asp:TextBox><label><img id="Image1" style=" Width:150px; Height:30px;" src="yanzhengma.aspx" alt="看不清换一张" onclick="change()"/></label> 11 </td>
当然还有其他的页面排版呀什么的,我就不一一写出来,就把最主要的部分写出来。
最后的效果,图片比较丑,主要还是个人的美工不好哇!
希望能帮到你哟..........
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