用C#编写网页怎么生成验证码
发布网友
发布时间：2022-04-22 03:48
共4个回答
热心网友
时间：2022-04-27 09:43
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.Mvc;
namespace News.Controllers
{
public class ImageCodeController : Controller
{
//
// GET: /ImageCode/
public ActionResult Index()
{
return View();
}
#region 生成图片验证码
/// <summary>
/// 比较图片中的字符和用户输入的字符
/// </summary>
/// <param name="uCode"></param>
/// <returns></returns>
public string GetCodeResult(string uCode)
{
string oldcode = Session["oldcode"] as string;
if (uCode.ToLower() == oldcode.ToLower())
{
return "yes";//用户输入正确
}
else
{
return "no";//用户输入错误
}
}
/// <summary>
/// 生成指定长度的字符串
/// </summary>
/// <returns></returns>
public ActionResult SecurityCode()
{
string code = CreateRandomCode(4); //验证码的字符为4个
Session["oldcode"] = code;//生成后，存在session中，用于和用户输入的值比较
return File(CreateValidateGraphic(code), "image/Jpeg");
}
/// <summary>
/// 生成随机的字符串
/// </summary>
/// <param name="codeCount"></param>
/// <returns></returns>
public string CreateRandomCode(int codeCount)
{
string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,a,b,c,d,e,f,g,h,i,g,k,l,m,n,o,p,q,r,F,G,H,I,G,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,s,t,u,v,w,x,y,z";
string[] allCharArray = allChar.Split(',');
string randomCode = "";
int temp = -1;
Random rand = new Random();
for (int i = 0; i < codeCount; i++)
{
if (temp != -1)
{
rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
}
int t = rand.Next(35);
if (temp == t)
{
return CreateRandomCode(codeCount);
}
temp = t;
randomCode += allCharArray[t];
}
return randomCode;
}
/// <summary>
/// 创建验证码图片
/// </summary>
/// <param name="validateCode"></param>
/// <returns></returns>
public byte[] CreateValidateGraphic(string validateCode)
{
Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 16.0), 27);
Graphics g = Graphics.FromImage(image);
try
{
//生成随机生成器
Random random = new Random();
//清空图片背景色
g.Clear(Color.White);
//画图片的干扰线
for (int i = 0; i < 25; i++)
{
int x1 = random.Next(image.Width);
int x2 = random.Next(image.Width);
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);
g.DrawLine(new Pen(Color.Silver), x1, x2, y1, y2);
}
Font font = new Font("Arial", 13, (FontStyle.Bold | FontStyle.Italic));
LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(validateCode, font, brush, 3, 2);
//画图片的前景干扰线
for (int i = 0; i < 100; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
image.SetPixel(x, y, Color.FromArgb(random.Next()));
}
//画图片的边框线
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
//保存图片数据
MemoryStream stream = new MemoryStream();
image.Save(stream, ImageFormat.Jpeg);
//输出图片流
return stream.ToArray();
}
finally
{
g.Dispose();
image.Dispose();
}
}
#endregion
}
}
----------------------控制器（上）------页面（下）-------------------------------
@{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
<script src="~/js/jquery-1.7.2.min.js"></script>
</head>
<body>
<div>
<img src="/ImageCode/SecurityCode" id="imageclick" onclick="this.src=this.src+'?'" />
<input type="text" value="" id="uCode" />
<a href="javaScript:;" id="click">确定</a>
</div>
</body>
</html>
<script type="text/javascript">
$("#click").click(function () {
//用户输入
var uCode = $.trim($("#uCode").val());
//图片中显示的
//获取点击图片后获取的值,并和用户输入的值进行比较
$.post("/ImageCode/GetCodeResult", { uCode: uCode }, function (data) {
if (data == "yes") {
alert("yes");
} else {
alert("验证码输入错误，请重新输入");
//$("#imageclick").click();//错误后，自动点击图片，生成下一个验证码（可选）
}
});
});
</script>
热心网友
时间：2022-04-27 11:01
上网上找一个,别自己写.找个javascript的.放到页面中就行.在按钮点击的时候调用一些就行了.
热心网友
时间：2022-04-27 12:35
最简单的办法是做N张验证码的图片，每张对应相应的value值，验证时只需验证输入的字符与value是否一样就OK了
热心网友
时间：2022-04-27 14:27
使用一般处理程序写追问纳尼？有代码吗？
追答http://www.cnblogs.com/nyzhai/archive/2013/07/30/CheckCode.html
