ASP英文字母加數(shù)字隨機驗證碼

1、ASP英文字母加數(shù)字隨機驗證碼(4位)charAndNum_checkCode.asp <% Sub ImageValidCode(sName) Response.Expires = -1 Response.AddHeader "Pragma","no-cache" Response.AddHeader "cache-ctrol","no-cache" Response.ContentType = "Image/BMP" Randomize Dim i, ii, iii Const cOd

2、ds = 4 '雜點出現(xiàn)的機率 Const cAmount = 36 ' 文字數(shù)量 Const cCode = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" '顏色的數(shù)據(jù)(字符，背景) Dim vColorData(1) vColorData(0) = ChrB(255) & ChrB(000) & ChrB(000) '字符顏色 vColorData(1) = ChrB(000) & ChrB(255) & ChrB(255) '背景顏色 Dim vCode(4), v

3、Codes For i=0 To 3 vCode(i) = Int(Rnd * cAmount) vCodes = vCodes & Mid(cCode, vCode(i)+1, 1) Next Session.Value(sName) = vCodes'記錄入Session Dim vNumberData(35) ' 輸出圖像文件頭 Response.BinaryWrite ChrB(66) & ChrB(77) & ChrB(230) & ChrB(4) & ChrB(0) & ChrB(0) & ChrB(0) &a

4、mp; ChrB(0) & ChrB(0) & ChrB(0) & ChrB(54) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(40) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(40) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(10) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(1) & ChrB(0) '

5、; 輸出圖像信息頭 Response.BinaryWrite ChrB(24) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(176) & ChrB(4) & ChrB(0) & ChrB(0) & ChrB(18) & ChrB(11) & ChrB(0) & ChrB(0) & ChrB(18) & ChrB(11) & ChrB(0) & ChrB(0) & ChrB(0) &a

6、mp; ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) For i=9 To 0 Step -1 ' 歷經(jīng)所有行 For ii=0 To 3 ' 歷經(jīng)所有字 For iii=1 To 10 ' 歷經(jīng)所有像素 If Rnd * 99 + 1 < cOdds Then ' 隨機生成雜點 Response.BinaryWrite vColorData(0) Else Response.BinaryWrite vColorData

7、(Mid(vNumberData(vCode(ii), i*10+iii, 1) End If Next Next Next End Sub Call ImageValidCode("GetCode") %> web頁面上的引用 Java代碼 <tr bgcolor="#F9F9F9"> <td width="89"> <div align="right"> <font color="#FF0000">*</font>驗證碼： &

8、lt;/div> </td> <td width="396"><input name="checkCode" type="text" size="6"> <img src="charAndNum_CheckCode.asp" alt="看不清楚?請點擊刷新" onclick="this.src=this.src+'?'+Math.random();" style="CURSOR:ha

9、nd;"> </td> </tr> <tr bgcolor="#F9F9F9"> <td width="89"> <div align="right"> <font color="#FF0000">*</font>驗證碼： </div> </td> <td width="396"><input name="checkCode" type

10、="text" size="6"> <img src="charAndNum_CheckCode.asp" alt="看不清楚?請點擊刷新" onclick="this.src=this.src+'?'+Math.random();" style="CURSOR:hand;"> </td> </tr>注意輸入的驗證碼與產(chǎn)生的驗證碼是否相同,應(yīng)該在提交處理中驗證,不能在頁面上用JS獲取Session驗證,否則獲得的session值將是上次產(chǎn)生的session值,主要原因是加載web頁面與生成驗證碼圖片不同步的問題 提交頁面的代碼 Java代碼 checkCode = request.Form("checkCode") if (trim(checkCode)<>session("GetCode") then Response.Write(&qu