JQuery AJAX -Validierung Verwenden Sie die Remote -Regel

// 验证用户邮箱
$(':input[name="uAcc"]').rules("add", {
  "remote": {
      url: 'validateEmail.php',
      type: "post",
      data: {
          emails: function() {
              return $('#register-form :input[name="email"]').val();
          }
      }
  }
});

// 验证用户邮箱
$.validator.addMethod("validateUserEmail", function(value, element) {
    var inputElem = $('#register-form :input[name="email"]'),
        data = { "emails": inputElem.val() },
        eReport = ''; // 错误报告

    $.ajax({
        type: "POST",
        url: 'validateEmail.php',
        dataType: "json",
        data: data,
        success: function(data) {
            if (data !== 'true') {
              return '此邮箱地址已注册。';
            } else {
               return true;
            }
        },
        error: function(xhr, textStatus, errorThrown) {
            alert('AJAX加载错误... ... ' + url + query);
            return false;
        }
    });

}, '');

$(':input[name="email"]').rules("add", { "validateUserEmail": true });

<?php
/* 检查邮箱是否已注册 */

// 使用mysqli连接数据库

if (!empty($_POST['email'])) {
    $email = $mysqli->real_escape_string($_POST['email']);
    $query = "SELECT ID FROM users WHERE user_email = '{$email}' LIMIT 1;";
    $results = $mysqli->query($query);
    if ($results->num_rows == 0) {
        echo "true";  // 可以注册
    } else {
        echo "false"; // 已注册
    }
} else {
    echo "false"; // 无效的POST变量
}

?>

/* 注册脚本 */

(function($, W, D, undefined) {
    $(D).ready(function() {

         // 表单验证规则
         $("#register-form").validate({
             rules: {
                email: {
                    required: true,
                    email: true,
                    "remote": {
                      url: 'validateEmail.php',
                      type: "post",
                      data: {
                          email: function() {
                              return $('#register-form :input[name="email"]').val();
                          }
                      }
                    }
                },
                name: {
                    required: true,
                    minlength: 3
                },
                password: {
                    required: true,
                    minlength: 8
                },
                password_repeat: {
                    required: true,
                    equalTo: "#password", // 修正equalTo的用法
                    minlength: 8
                }
             },
             messages: {
                 email: {
                    required: "请输入您的邮箱地址。",
                    email: "请输入有效的邮箱地址。",
                    remote: jQuery.validator.format("{0}已被占用。")
                 },
                 name: "请输入您的姓名。",
                 password: "请输入密码。",
                 password_repeat: "两次密码必须一致。"
             },
             submitHandler: function(form) {
                form.submit();
             }
         });

    });

})(jQuery, window, document);

$("#register-form").validate({
   onkeyup: false // 输入时关闭自动验证
});