首先看下效果實(shí)現(xiàn)（由于gif屏幕錄制軟件是即時(shí)找的，有些失禎）
代碼主要就是繪制驗(yàn)證碼類的實(shí)現(xiàn)
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using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Drawing;using System.IO;namespace SecurityCodePic{ public class DrawingSecurityCode { /// <summary> /// 生成驗(yàn)證碼，并返回 /// </summary> /// <returns></returns> public string GetSecurityCode(int n) { string code = GenerateCheckCode(n); CreateCheckCodeImage(code); return code; } /// <summary> /// 動(dòng)態(tài)生成指定數(shù)目的隨機(jī)數(shù)或字母 /// </summary> /// <param name="num">整數(shù)</param> /// <returns>返回驗(yàn)證碼字符串</returns> private string GenerateCheckCode(int num) { int number;//定義變量 char code; string checkCode = String.Empty; //空字符串，只讀 Random random = new Random(); //定義隨機(jī)變量實(shí)例 for (int i=0; i < num;i++ ) { //利用for循環(huán)生成指定數(shù)目的隨機(jī)數(shù)或字母 number = random.Next(); //返回一個(gè)小于指定的最大值的非負(fù)的隨機(jī)數(shù) next有三個(gè)構(gòu)造函數(shù) if (number % 2 == 0) {//產(chǎn)生一個(gè)一位數(shù) code = (char)('0' + (char)(number % 10)); } else { //產(chǎn)生一個(gè)大寫(xiě)字母 code = (char)('A'+(char)(number % 26)); } checkCode += code.ToString(); } return checkCode; } /// <summary> /// 根據(jù)驗(yàn)證碼字符串生成驗(yàn)證碼圖片 /// </summary> /// <param name="checkCode">驗(yàn)證碼字符串</param> private void CreateCheckCodeImage(string checkCode) { if (checkCode == null || checkCode.Trim() == String.Empty) return; // 引用System.Drawing類庫(kù) Bitmap myImage = new Bitmap(80, 30);//生成一個(gè)指定大小的位圖 Graphics graphics = Graphics.FromImage(myImage); //從一個(gè)位圖生成一個(gè)畫(huà)布 try { graphics.Clear(Color.White); //清除整個(gè)繪畫(huà)面并以指定的背景色填充,這里是把背景色設(shè)為白色 Random random = new Random(); //實(shí)例化一個(gè)偽隨機(jī)數(shù)生成器 //畫(huà)圖片的前景噪音點(diǎn),這里有100個(gè) for (int i = 0; i < 100; i++) { int x = random.Next(myImage.Width); int y = random.Next(myImage.Height); myImage.SetPixel(x, y, Color.FromArgb(random.Next()));//指定坐標(biāo)為x,y處的像素的顏色 } //畫(huà)圖片的背景噪音線,這里為2條 for (int i = 0; i < 2; i++) { int x1 = random.Next(myImage.Width); int x2 = random.Next(myImage.Width); int y1 = random.Next(myImage.Height); int y2 = random.Next(myImage.Height); graphics.DrawLine(new Pen(Color.Black), x1, y1, x2, y2); //繪制一條坐標(biāo)x1,y1到坐標(biāo)x2,y2的指定顏色的線條，這里的線條為黑色 } Font font = new Font("Arial", 15, FontStyle.Bold); //定義特定的文本格式,這里的字體為Arial，大小為15,字體加粗 //根據(jù)矩形、起始顏色和結(jié)束顏色以及方向角度產(chǎn)生一個(gè)LinearGradientBrush實(shí)例---線性漸變 System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush( new Rectangle(0, 0, myImage.Width, myImage.Height),//在坐標(biāo)0,0處實(shí)例化一個(gè)和myImage同樣大小的矩形 Color.Blue, Color.Red, 1.2f, true); //繪制文本字符串 graphics.DrawString(checkCode, font, brush, 2, 2); //繪制有坐標(biāo)對(duì)、寬度和高度指定的矩形---畫(huà)圖片的邊框線 graphics.DrawRectangle(new Pen(Color.Silver), 0, 0, myImage.Width - 1, myImage.Height - 1); //創(chuàng)建其支持存儲(chǔ)器為內(nèi)存的流 MemoryStream ms = new MemoryStream(); //將此圖像以指定格式保存到指定的流中 myImage.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); //這里是以gif的格式保存到內(nèi)存中 HttpContext.Current.Response.ClearContent(); //清除緩沖區(qū)流中的所有內(nèi)容輸出 HttpContext.Current.Response.ContentType = "image/Gif"; //獲取或設(shè)置輸出流的HTTP MIME類型 HttpContext.Current.Response.BinaryWrite(ms.ToArray()); //將一個(gè)二進(jìn)制字符串寫(xiě)入HTTP輸出流 } finally { //釋放占用資源 graphics.Dispose(); myImage.Dispose(); } } }} |
然后使用SecurityCode.ashx文件調(diào)用上面類的方法實(shí)現(xiàn)
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using System;using System.Collections.Generic;using System.Linq;using System.Web;namespace SecurityCodePic{ /// <summary> /// SecurityCode1 的摘要說(shuō)明 /// </summary> public class SecurityCode1 : IHttpHandler { public void ProcessRequest(HttpContext context) { DrawingSecurityCode sc = new DrawingSecurityCode(); string SecurityCode = sc.GetSecurityCode(6); } public bool IsReusable { get { return false; } } }} |
最后就是ASP.NET頁(yè)面圖片路徑的引用了
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<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="SecurityCode_Test.aspx.cs" Inherits="SecurityCodePic.SecurityCode_Test" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"> <title>驗(yàn)證碼的實(shí)現(xiàn)</title> <style type="text/css"> #VCodeImg { cursor: pointer;} </style></head><body> <form id="form1" runat="server"> <div> <img id="VCodeImg" src="SecurityCode.ashx" alt="驗(yàn)證碼" onclick="javascript:RefreshCode();" /> </div> </form> <script type="text/javascript"> function RefreshCode() { var random = Math.random(); var img = document.getElementById("VCodeImg"); img.src = "SecurityCode.ashx?" + random; //加上無(wú)意義的隨機(jī)參數(shù)，瀏覽器才會(huì)認(rèn)為是新地址，就會(huì)重新讀取數(shù)據(jù) } </script></body></html> |
以上就是本文的全部，對(duì)了，還有源碼下載分享給大家，歡迎大家下載。
