我刚刚发现 isset 函数不再适用于我的登录和注册表单。不过我很奇怪，所以我取消了我最近所做的一切，看看是否是它造成的，但没有运气。如果我删除 isset 并替换为这个；

if($_SERVER['REQUEST_METHOD'] == "POST"){

有效!但是我在一个页面上有两个表单，所以我需要检查提交的是哪一个。

这是 isset 函数:

if (isset($_POST['submit_login'])) {

提交按钮只是为了让您知道它的名称是正确的；

<input type="submit" name="submit_login" value="Login" class="buttonClassic"/>

注册表格完全相同，但名称为 submit_reg。

表格:

<form action="<?php echo htmlentities('Login'); ?>" method="post" id="login"> 
   <p class="p1">Already signed up? Log in</p><hr/>
   <label for="email">Your email address </label><input type="email" required name="email" placeholder="Email" class="text" id="email">
   <label for="password">Your password </label><input type="password"  name="pass" required placeholder="Password" class="text" id="password">
   <center><input type="submit" name="submit_login" value="Login" class="buttonClassic"/></center>
   <div class="center-align-text">
       <p class="p3"><a href="passreset.html">Forgotten your password?</a></p>
   </div>
</form> 

注册表格:

<form action="<?php echo htmlentities('Login'); ?>" method="post" id="register" >
   <p class="p1">New to NBS? Sign up, it's free!</p><hr/>
   <label for="reg_email">What's your email address? </label><input type="email" name="email" required placeholder="Email" class="text" id="reg_email">
   <label for="reg_password">Choose a password </label><input type="password" required name="pass" placeholder="Password" class="text" id="reg_password">
   <label for="reg_password2">Re-type password </label><input type="password" required name="pass2" placeholder="Re-type password" class="text" id="reg_password2">
   <input type="checkbox" name="subscribed" value="subscribed" id="subscribed"><label for="subscribed">Yes, send me email updates from NewBorn Sounds. </label>
   <br/>
   <input type="checkbox" required="flag" name="terms" value="ticked" id="terms"><label for="terms">I agree to the <a href="Terms">terms & conditions</a>.</label>

   <center><input type="submit" name="submit_reg" value="Sign Up" class="buttonClassic"></center>
</form> 

如果您需要更多，请大声喊叫!

哦，我知道我可以将表单提交到外部 PHP 脚本，但我并不是特别想这样做，因为我希望将用户输入错误输出到同一页面。我知道我可以只使用 ajax，我确实这样做了，但我试图将 javascript 保留为一个附加组件，而不是因为没有 js 而降低用户体验。

完整的 HTML:

<div id="login_form_wrapper">

<form action="Login" method="post" id="login" novalidate="novalidate"> 
   <p class="p1">Already signed up? Log in</p><hr>
   <label for="email">Your email address </label><input type="email" required="" name="email" placeholder="Email" class="text" id="email">
   <label for="password">Your password </label><input type="password" name="pass" required="" placeholder="Password" class="text" id="password">
   <center><input type="submit" name="submit_login" value="Login" class="buttonClassic"></center>
   <div class="center-align-text">
       <p class="p3"><a href="passreset.html">Forgotten your password?</a></p>
   </div>
</form> 


<form action="Login" method="post" id="register" novalidate="novalidate">
   <p class="p1">New to NBS? Sign up, it's free!</p><hr>
   <label for="reg_email">What's your email address? </label><input type="email" name="email" required="" placeholder="Email" class="text" id="reg_email">
   <label for="reg_password">Choose a password </label><input type="password" required="" name="pass" placeholder="Password" class="text" id="reg_password">
   <label for="reg_password2">Re-type password </label><input type="password" required="" name="pass2" placeholder="Re-type password" class="text" id="reg_password2">
   <input type="checkbox" name="subscribed" value="subscribed" id="subscribed"><label for="subscribed">Yes, send me email updates from NewBorn Sounds. </label>
   <br>
   <input type="checkbox" required="flag" name="terms" value="ticked" id="terms"><label for="terms">I agree to the <a href="Terms">terms &amp; conditions</a>.</label>

   <center><input type="submit" name="submit_reg" value="Sign Up" class="buttonClassic"></center>
</form> 

</div>

最佳答案

也许你可以这样做:

if($_SERVER['REQUEST_METHOD'] == "POST"){ 
 if (isset($_POST['submit_login'])) { 
    //do something
 } else {
   //do something else
 }

}

关于用于提交检查的 PHP isset 函数不起作用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16873781/