<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>Title</title></head><body><form method="post" action="doLogin.php"> <input type="text" placeholder="用户名" name="username"><br><br> <input type="password" placeholder="密码" name="password"><br><br> <input type="text" placeholder="验证码" name="verifycode" class="captcha"><br><br> <img id="captcha_img" src="captcha.php?r=<?php echo rand();?>" <label><a href="javascript:void(0)" rel="external nofollow" onclick="document.getElementById('captcha_img').src='captcha.php?r='+Math.random()">换一个</a> </label><br> <label><input type="checkbox" name="autologin[]" value="1"/>自动登录</label><br> <button type="submit">登录</button></form></body></html> <?phpheader("Content-type:text/html;charset=UTF-8");require "mysql.php"; //导入mysql.php访问数据库session_start(); //开启会话一获取到服务器端验证码$username=$_POST['username'];$password=$_POST['password'];$autologin=isset($_POST['autologin'])?1:0; //获取是否选择了自动登录$verifycode=$_POST['verifycode'];$code=$_SESSION['code']; //获取服务器生成的验证码/* * 首先进行判空操作，通过后进行验证码验证，通过后再进行数据库验证。 * 手机号码和邮箱验证可根据需要自行添加 * */if(checkEmpty($username,$password,$verifycode)){ if(checkVerifycode($verifycode,$code)){ if(checkUser($username,$password)){ $_SESSION['username']=$username; //保存此时登录成功的用户名 if($autologin==1){ //如果用户勾选了自动登录就把用户名和加了密的密码放到cookie里面 setcookie("username",$username,time()+3600*24*3); //有效期设置为3天 setcookie("password",md5($password),time()+3600*24*3); } else{ setcookie("username","",time()-1); //如果没有选择自动登录就清空cookie setcookie("password","",time()-1); } header("location: index.php "); //全部验证都通过之后跳转到首页 } }}//方法：判断是否为空function checkEmpty($username,$password,$verifycode){ if($username==null||$password==null){ echo '<html><head><Script Language="JavaScript">alert("用户名或密码为空");</Script></head></html>' . "<meta http-equiv=/"refresh/" content=/"0;url=login.html/">"; } else{ if($verifycode==null){ echo '<html><head><Script Language="JavaScript">alert("验证码为空");</Script></head></html>' . "<meta http-equiv=/"refresh/" content=/"0;url=login.html/">"; } else{ return true; } }}//方法：检查验证码是否正确function checkVerifycode($verifycode,$code){ if($verifycode==$code){ return true; } else{ echo '<html><head><Script Language="JavaScript">alert("验证码错误");</Script></head></html>' . "<meta http-equiv=/"refresh/" content=/"0;url=login.html/">"; }}//方法：查询用户是否在数据库中function checkUser($username,$password){ $conn=new Mysql(); $sql="select * from user where name='{$username}' and password='{$password}';"; $result=$conn->sql($sql); if($result){ return true; } else{ echo '<html><head><Script Language="JavaScript">alert("用户不存在");</Script></head></html>' . "<meta http-equiv=/"refresh/" content=/"0;url=login.html/">"; } $conn->close();}//方法：手机格式验证function checkPhoneNum($phonenumber){ $preg="/^1[34578]{1}/d{9}$/"; if(preg_match($preg,$phonenumber)){ return ture; //验证通过 }else{ echo '<html><head><Script Language="JavaScript">alert("手机号码格式有误");</Script></head></html>' . "<meta http-equiv=/"refresh/" content=/"0;url=login.html/">";//手机号码格式不对 }}//方法：邮箱格式验证function checkEmail($email){ $preg = '/^(/w{1,25})@(/w{1,16})(/.(/w{1,4})){1,3}$/'; if(preg_match($preg, $email)){ return true; }else{ echo '<html><head><Script Language="JavaScript">alert("y邮箱格式有误");</Script></head></html>' . "<meta http-equiv=/"refresh/" content=/"0;url=login.html/">"; }} <?php//退出登录并跳转到登录页面unset($_SESSION['username']);setcookie("username","",time()-1); //清空cookiesetcookie("password","",time()-1);header("location: login.html "); <?phpsession_start();if(empty($_COOKIE['username'])&&empty($_COOKIE['password'])){ if(isset($_SESSION['username'])) echo "登录成功，欢迎您".$_SESSION['username']."<a href='logout.php'>退出登录</a>"; else echo "你还没有登录，<a href='login.html'>请登录</a>";}else echo "登录成功，欢迎您：".$_COOKIE['username']."<a href='logout.php'>退出登录</a>"; 
