一、ASPX 登陆界面验证码
1、登陆验证码图片和输入验证码框
<asp:TextBox ID="txtValiCode" runat="server" Width="50px"></asp:TextBox>
<asp:Image ID="ValiCode" ImageUrl="CreateValiImg.aspx" runat="server" style="position:relative;top:4px;" />
2、js
$(function () {
$("#loginBtn").click(function () {
var Pwd = $("#PwdTbx").val();
var md5pwd = $.md5(Pwd);
$("#PwdTbx").val(md5pwd);
});
$("#txtValiCode").val("");
$("#ValiCode").click(function () {
location.reload();
});
});
3、创建生产验证码的aspx页 CreateValiImg.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="CreateValiImg.aspx.cs" Inherits="CreateValiImg" %> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div> </div>
</form>
</body>
</html>
后台代码
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls; public partial class CreateValiImg : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string validateNum = CreateRandomNum();
CreateImage(validateNum);
Session["ValidateNum"] = validateNum;
} //生产随机数
private string CreateRandomNum(int NumCount)
{
string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,O,P,Q,R,S,T,U,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,m,n,o,p,q,s,t,u,w,x,y,z";
string[] allCharArray = allChar.Split(',');//拆分成数组
string randomNum = "";
int temp = -; //记录上次随机数的数值，尽量避免产生几个相同的随机数
Random rand = new Random();
for (int i = ; i < NumCount; i++)
{
if (temp != -)
{
rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
}
int t = rand.Next();
if (temp == t)
{
return CreateRandomNum(NumCount);
}
temp = t;
randomNum += allCharArray[t]; }
return randomNum;
}
//生产图片
private void CreateImage(string validateNum)
{
if (validateNum == null || validateNum.Trim() == string.Empty)
return;
//生成BitMap图像
System.Drawing.Bitmap image = new System.Drawing.Bitmap(validateNum.Length * + , );
Graphics g = Graphics.FromImage(image);
try
{
//生成随机生成器
Random random = new Random();
//清空图片背景
g.Clear(Color.White);
//画图片的背景噪音线
for (int i = ; i < ; 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 System.Drawing.Font("Arial", , (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(, , image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(validateNum, font, brush, , );
//画图片的前景噪音点
for (int i = ; i < ; 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), , , image.Width - , image.Height - );
System.IO.MemoryStream ms = new System.IO.MemoryStream();
//将图像保存到指定流
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
4、运行效果
5、登陆提交账号密码验证码的时候验证
if (ValiCode != Session["ValidateNum"].ToString()){ ... }
二、MVC中使用验证码
1、在登陆页添加输入验证码框和图片
验证码 <input ID="txtValiCode" type="text" style="width:60px;" />
<img ID="ValiCode" src="/Login/CreatevaliImg" style="position:relative;top:4px;" />
2、登陆界面js、点击验证码图片刷新验证码
$(function () {
$("#txtValiCode").val("");
$("#ValiCode").click(function () {
location.reload();
});
});
3、在controller里添加 CreatevaliImg 方法生产验证码，供界面里img url调用
public void CreatevaliImg()
{
string validateNum = CreateRandomNum();
CreateImage(validateNum);
Session["ValidateNum"] = validateNum;
} //生产随机数
private string CreateRandomNum(int NumCount)
{
string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,O,P,Q,R,S,T,U,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,m,n,o,p,q,s,t,u,w,x,y,z";
string[] allCharArray = allChar.Split(',');//拆分成数组
string randomNum = "";
int temp = -; //记录上次随机数的数值，尽量避免产生几个相同的随机数
Random rand = new Random();
for (int i = ; i < NumCount; i++)
{
if (temp != -)
{
rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
}
int t = rand.Next();
if (temp == t)
{
return CreateRandomNum(NumCount);
}
temp = t;
randomNum += allCharArray[t]; }
return randomNum;
}
//生产图片
private void CreateImage(string validateNum)
{
if (validateNum == null || validateNum.Trim() == string.Empty)
return;
//生成BitMap图像
System.Drawing.Bitmap image = new System.Drawing.Bitmap(validateNum.Length * + , );
Graphics g = Graphics.FromImage(image);
try
{
//生成随机生成器
Random random = new Random();
//清空图片背景
g.Clear(Color.White);
//画图片的背景噪音线
for (int i = ; i < ; 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 System.Drawing.Font("Arial", , (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(, , image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(validateNum, font, brush, , );
//画图片的前景噪音点
for (int i = ; i < ; 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), , , image.Width - , image.Height - );
System.IO.MemoryStream ms = new System.IO.MemoryStream();
//将图像保存到指定流
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
4、运行效果
5、登陆的时候校验下 页面中的输入内容和 后台生成的 Session["ValidateNum"] 作校验