我有一个注册页面，如下所示，我将在那里发布回同一页面。
<?php
session_start();
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$_SESSION["registered"] = "success";
$count = insert_record($_POST['fname'],$_POST['lname'],$_POST['email'],$_POST['regusername'],$_POST['regpassword']);
header("Location: login.php");
}
$page_title = "Registration";
if(isset($_SESSION["username"]))
include('includes/header_authorized.html');
else
include('includes/header.html');
?>
<div class="container">
<div class="regform">
<form name="registration" id="registration" method="post" action="registration.php">
<p><span class="req">* required field.</span></p>
<ul>
<li><label for="fname">First Name:</label>
<input type="text" class="textboxborder" id="fname" name="fname" size="20" maxlength="25" autofocus="autofocus" value="<?php if(isset($_POST['fname'])) echo $_POST['fname'];?>"/>
<span class="error" id="errfname">*<?php if(isset($errfname)) echo $errfname;?></span>
</li>
<li><label for="lname">Last Name:</label>
<input type="text" class="textboxborder" id="lname" name="lname" size="20" maxlength="25" value="<?php if(isset($_POST['lname'])) echo $_POST['lname'];?>"/>
<span class="error" id ="errlname">*<?php if(isset($errlname)) echo $errlname;?></span>
</li>
<li><label for="email">Email:</label>
<input type="text" class="textboxborder" name="email" id="email" size="40" maxlength="50" placeholder="abc@xyz.com" value="<?php if(isset($_POST['email'])) echo $_POST['email'];?>"/>
<span class="error" id="erremail">*<?php if(isset($erremail)) echo $erremail;?></span>
</li>
<li><label for="regusername">Username:</label>
<input type="text" name="regusername" id="regusername" size="20" maxlength="30" value="<?php if(isset($_POST['regusername'])) echo $_POST['regusername'];?>"/>
<span class="error" id="errregusername">*<?php if(isset($errregusername)) echo $errregusername;?></span>
</li>
<li><label for="regpassword">Password:</label>
<input type="text" name="regpassword" id="regpassword" size="20" maxlength="15" value="<?php if(isset($_POST['regpassword'])) echo $_POST['regpassword'];?>"/>
<span class="error" id="errregpassword">*<?php if(isset($errregpassword)) echo $errregpassword;?></span>
</li>
<li><label for="regconpassword">Confirm Password:</label>
<input type="text" name="regconpassword" id="regconpassword" size="20" maxlength="15"/>
<span class="error" id="errregconpassword">*<?php if(isset($errregconpassword)) echo $errregconpassword;?></span>
</li>
</ul>
<div id="message_line"> <?php if(isset($error)) echo $error;?></div>
<div class="buttons">
<input type="reset" value="Reset" id="reset"/>
<input type="submit" value="Submit" id="submit"/>
</div>
</form>
<img src="images/loading.gif" id="busy_wait" alt="busy wait icon" />
</div>
</div>
</body>
</html>
在javascript中，我验证用户没有重复，并提交表单（我调试它运行良好，$('#registration').submit();被执行）
$('#submit').on('click', function(e) {
$('#message_line').text("");
if(validate_fields_on_submit()) {
e.preventDefault();
return;
}
var params = $('form').serialize();
var url = "check_duplicate.php?" + params;
var request = new HttpRequest(url, submitHandler);
request.send(params);
$('#busy_wait').css('display','block');
e.preventDefault();
});
function submitHandler(response) {
$('#message_line').text("");
response = $.trim(response);
if(response == "" && response.indexOf("<") <= -1)
$('#registration').submit();
else if(response.indexOf("<") == 0) {
var name = $('[name="regusername"]').val();
$('#message_line').text("Some error occured, please try after some time.");
$("#message_line").attr("tabindex",-1).focus();
} else {
var name = $('[name="regusername"]').val();
var arr = response.split(',');
arr.pop();
arr.toString();
$('#message_line').text("'" + name + "' already exists, Please try different username");
$("#regusername").focus();
}
$('#busy_wait').css('display','none');
}
在insert_record中，这就是我所拥有的
function insert_record($fname,$lname,$email,$username,$password) {
$conn = get_connection();
$to_insert = "INSERT INTO user VALUES ('$fname', '$lname', '$email', '$username', '$password', 20)";
if(!($result = mysqli_query($conn,$to_insert)))
return 0;
else
return mysqli_affected_rows($conn);
}
由于某种原因，当我点击提交时，在验证重复用户后不会发生任何事情。
如果我删除ajax调用以检查重复并直接提交它，它就可以正常工作。请说明我可能做错了什么。
我认为在添加一些库之前，它们在javascript中不是HttpRequest对象。请参阅您的代码
var request = new HttpRequest(url, submitHandler);
request.send(params);
此外，您正在以GET而非POST的格式发送参数。
相反，您需要使用XmlHttpRequest对象来发送ajax请求，如下所示。
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState == 4) {
submitHandler(xhr.responseText);
}
}
// xhr.open('GET', "check_duplicate.php?" + params, true);
// xhr.send(null);
xhr.open('POST', "check_duplicate.php", true);
xhr.send(params);
您还可以使用jQueryajax来简化
$.post('check_duplicate.php', params, function(responseText) {
submitHandler(responseText);
});