webform1.aspx<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="work068.WebForm1" %>
<!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>演示随机生成登录验证码</title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
webform1.aspx.csusing System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace work068
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//演示随机生成登录验证码
//验证码的字符集合
string checkCodeString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
//集合的长度
int length = checkCodeString.Length;
//建立字体，粗体
System.Drawing.Font font1 = new System.Drawing.Font("宋体", 24, System.Drawing.FontStyle.Bold);
//预备空画刷
System.Drawing.Brush brush1 = null;
//预备画刷颜色
System.Drawing.Color brushColor = new System.Drawing.Color();
//保存最后生成的验证码字符串
string checkCode = string.Empty;
//单个验证码
string code = string.Empty;
//建立位图
System.Drawing.Bitmap image1 = new System.Drawing.Bitmap(100, 40);
//从位图获取图像对象
System.Drawing.Graphics graphic1 = System.Drawing.Graphics.FromImage(image1);
//背景白色
graphic1.Clear(System.Drawing.Color.White);
//随机数
Random random1 = new Random();
//4位
for (int i = 0; i < 4; i++)
{
//取模运算
int current = random1.Next(DateTime.Now.Millisecond) % length;
//验证码字符串集合中截取字符
code = checkCodeString.Substring(current, 1);
//累加至验证码字符串中
checkCode += code;
//随机生成颜色
brushColor = System.Drawing.Color.FromArgb(random1.Next(255), random1.Next(255), random1.Next(255));
//给画刷加颜色
brush1 = new System.Drawing.SolidBrush(brushColor);
//图像对象中写入字符串，字符起点20像素宽，中间5像素隔开
graphic1.DrawString(code, font1, brush1, i * 20 + 5, 10);
}
//网页清空
Response.Clear();
//设置网页模式
Response.ContentType = "image/pjpeg";
//图片保存至网页流中
image1.Save(Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
//最后的验证码保存至会话层中
Session["CheckCode"] = checkCode;
//释放资源
graphic1.Dispose();
image1.Dispose();
Response.End();
}
}
}
webform2.aspx<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm2.aspx.cs" Inherits="work068.WebForm2" %>
<!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>在登录界面中使用验证码</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table border="0">
<tr>
<td>用户名</td>
<td>
<asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="必填" ControlToValidate="txtUserName" Display="Dynamic"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td>密码</td>
<td>
<asp:TextBox ID="txtPwd" runat="server"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ErrorMessage="必填" ControlToValidate="txtPwd" Display="Dynamic"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td>验证码</td>
<td>
<asp:TextBox ID="txtCheckCode" runat="server"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ErrorMessage="必填" ControlToValidate="txtCheckCode" Display="Dynamic"></asp:RequiredFieldValidator>
<img src="WebForm1.aspx" width="100" height="40" style="cursor:pointer" alt="点击刷新验证码"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:Button ID="Button1" runat="server" Text="登录" />
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
webform2.aspx.csusing System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace work068
{
public partial class WebForm2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Page.UnobtrusiveValidationMode = System.Web.UI.UnobtrusiveValidationMode.None;
txtUserName.Text = "虾米大王";
txtPwd.Text = "123";
}
protected void Button1_Click(object sender, EventArgs e)
{
string checkCode = Session["CheckCode"].ToString();
if (checkCode.ToUpper() == txtCheckCode.Text.ToUpper())
{
Response.Write("<script>window.alert('验证码正确，登录成功');</script>");
}
else
{
Response.Write("<script>window.alert('验证码错误，重新登录');</script>");
}
}
}
}
| 
编程语言
发布于：2021-12-04 23:17
|
阅读数：393
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评论：0
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