JS 实现随机验证码功能
1、验证码 验证是网页常出现的一个验证点，所谓验证码类型有很多，下面代码只是实现一个简单的验证功能。
<div>
<input type = "text" id = "input" value="" />
<input type = "button" id="code" onclick="createCode()"/>
<input type = "button" value = "验证" onclick = "validate()"/>
</div>
2、随便加点样式
#code{
font-family:Arial;
font-style:italic;
font-weight:bold;
border:0;
letter-spacing:2px;
color:blue;
}
3.JS部分，里面我已经加了详细的备注
//设置一个全局的变量，便于保存验证码
var code;
function createCode(){
//首先默认code为空字符串
code = '';
//设置长度，这里看需求，我这里设置了4
var codeLength = 4;
var codeV = document.getElementById('code');
//设置随机字符
var random = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R', 'S','T','U','V','W','X','Y','Z');
//循环codeLength 我设置的4就是循环4次
for(var i = 0; i < codeLength; i++){
//设置随机数范围,这设置为0 ~ 36
var index = Math.floor(Math.random()*36);
//字符串拼接 将每次随机的字符 进行拼接
code += random[index];
}
//将拼接好的字符串赋值给展示的Value
codeV.value = code;
}
//下面就是判断是否== 的代码，无需解释
function validate(){
var oValue = document.getElementById('input').value.toUpperCase();
if(oValue ==0){
alert('请输入验证码');
}else if(oValue != code){
alert('验证码不正确，请重新输入');
oValue = ' ';
createCode();
}else{
window.open('http://www.baidu.com','_self');
}
}
//设置此处的原因是每次进入界面展示一个随机的验证码，不设置则为空
window.onload = function (){
createCode();
}
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第三方验证控件
一般处理程序
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.SessionState;
namespace UI
{
/// <summary>
/// ValidateCode1 的摘要说明
/// </summary>
public class ValidateCode1 : IHttpHandler, IRequiresSessionState
{
/// <summary>
/// 验证码类型(0-字母数字混合,1-数字,2-字母)
/// </summary>
private string validateCodeType = "0";
/// <summary>
/// 验证码字符个数
/// </summary>
private int validateCodeCount = 4;
/// <summary>
/// 验证码的字符集，去掉了一些容易混淆的字符
/// </summary>
char[] character = { '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
public void ProcessRequest(HttpContext context)
{
context.Response.BufferOutput = true;
context.Response.Cache.SetExpires(DateTime.Now.AddMilliseconds(-1));
context.Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache);
context.Response.AppendHeader("Pragma", "No-Cache");
//获取设置参数
if (!string.IsNullOrEmpty(context.Request.QueryString["validateCodeType"]))
{
validateCodeType = context.Request.QueryString["validateCodeType"];
}
if (!string.IsNullOrEmpty(context.Request.QueryString["validateCodeCount"]))
{
int.TryParse(context.Request.QueryString["validateCodeCount"], out validateCodeCount);
}
//生成验证码
this.CreateCheckCodeImage(GenerateCheckCode(context), context);
}
private string GenerateCheckCode(HttpContext context)
{
char code;
string checkCode = String.Empty;
System.Random random = new Random();
for (int i = 0; i < validateCodeCount; i++)
{
code = character[random.Next(character.Length)];
// 要求全为数字或字母
if (validateCodeType == "1")
{
if ((int)code < 48 || (int)code > 57)
{
i--;
continue;
}
}
else if (validateCodeType == "2")
{
if ((int)code < 65 || (int)code > 90)
{
i--;
continue;
}
}
checkCode += code;
}
context.Response.Cookies.Add(new System.Web.HttpCookie("CheckCode", checkCode));
context.Session.Add("CheckCode",checkCode);
return checkCode;
}
private void CreateCheckCodeImage(string checkCode, HttpContext context)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling
((checkCode.Length * 15.0 + 40)), 23);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
try
{
//生成随机生成器
Random random = new Random();
//清空图片背景色
g.Clear(System.Drawing.Color.White);
//画图片的背景噪音线
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 System.Drawing.Pen(System.Drawing.Color.Silver), x1, y1, x2,
y2);
}
System.Drawing.Font font = new System.Drawing.Font("Arial", 14,
(System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
System.Drawing.Drawing2D.LinearGradientBrush brush = new
System.Drawing.Drawing2D.LinearGradientBrush(new System.Drawing.Rectangle(0, 0,
image.Width, image.Height), System.Drawing.Color.Blue, System.Drawing.Color.DarkRed, 1.2f,
true);
int cySpace = 16;
for (int i = 0; i < validateCodeCount; i++)
{
g.DrawString(checkCode.Substring(i, 1), font, brush, (i + 1) * cySpace, 1);
}
//画图片的前景噪音点
for (int i = 0; i < 100; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
image.SetPixel(x, y, System.Drawing.Color.FromArgb(random.Next()));
}
//画图片的边框线
g.DrawRectangle(new System.Drawing.Pen(System.Drawing.Color.Silver), 0, 0,
image.Width - 1, image.Height - 1);
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
context.Response.ClearContent();
context.Response.ContentType = "image/Gif";
context.Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
public bool IsReusable
{
get
{
return false;
}
}
}
}
显示:
<p>验证码:<input type="text" name="Yan" /><img src="/Content/ValidateCode.ashx" onclick="this.src = '/Content/ValidateCode.ashx?id='+new Date()"></p>
验证:Yan.ToUpper() == Session["CheckCode"].ToString()