防止发生默认操作？ （JQueryMobile）

Question

我刚刚实施了输入字段验证，例如，如果输入字段为空，则“请输入您的姓名”。

我通过JQuery mobile完成了此操作，但是我没有的问题是，当用户提交（registerUser（）;）表单时，验证不会及时发生（如果为空），而是将数据提交到数据库中。

如果存在空白字段，如何防止页面将数据加载并解析到数据库中？

HTML-

<form id="form1">
        <div data-role="fieldcontainer">
            <label for="txtusername" data-theme="d">Username:</label>
            <input type="text" id="txtusername" name="txtusername" data-theme="d" placeholder="Enter Username"/>
        </div>
        <div data-role="fieldcontainer">
            <label for="txtfirstname" data-theme="d">First Name:</label>
            <input type="text" id="txtfirstname" name="txtfirstname" data-theme="d" placeholder="Enter First Name"/>
        </div>
        <div data-role="fieldcontainer">
            <label for="txtlastname" data-theme="d">Last Name:</label>
            <input type="text" id="txtlastname" name="txtlastname" data-theme="d" placeholder="Enter Last Name"/>
        </div>
        <div data-role="fieldcontainer">
            <label for="txtemail" data-theme="d">Email:</label>
            <input type="email" id="txtemail" name="txtemail" data-theme="d" placeholder="Enter Enter Email"/>
        </div>
        <div data-role="fieldcontainer">
            <label for="txtpassword" data-theme="d">Password:</label>
            <input type="text" id="txtpassword" name="txtpassword" data-theme="d" placeholder="Enter Password"/>
        </div>
        <div data-role="fieldcontainer">
            <label for="passwordconfirm" data-theme="d">Confirm Password:</label>
            <input type="text" id="passwordconfirm" name="passwordconfirm" data-theme="d" placeholder="Confirm password"/>
        </div>
        <br>
        <input type="submit" value="Register User" onclick="return registerUser(); return false;">

JavaScript档案（JQuery Mobile）-

 $('#form1').validate({
                         rules: {
                            txtusername: {
                                 required: true
                             },
                             txtfirstname: {
                                 required: true
                             },
                             txtlastname: {
                                 required: true
                             },
                             txtemail: {
                                 required: true
                                     },
                             txtpassword: {
                                   required: true
                                          },
                            passwordconfirm: {
                                   required: true
                                   }
                         },
                         messages: {
                             txtusername: {
                                 required: "Please enter your Username."
                             },
                             txtfirstname: {
                                 required: "Please enter your First Name."
                             },
                             txtlastname: {
                                 required: "Please enter your Last Name."
                             },
                             txtemail: {
                                     required: "Please enter your Email."
                                          },
                             txtpassword: {
                                    required: "Please enter your Password."
                                },
                             passwordconfirm: {
                                  required: "Please enter your password again."
                                 }
                         },
                         errorPlacement: function (error, element) {
                             error.appendTo(element.parent().prev());
                         },
                         submitHandler: function (form) {
                             $(':mobile-pagecontainer').pagecontainer('change', '#success', {
                                 reload: false
                             });
                             return false;
                         }
                     });

userRegister函数

 function registerUser() {
       var Username = document.getElementById("txtusername").value;
       var Firstname = document.getElementById("txtfirstname").value;
       var Lastname = document.getElementById("txtlastname").value;
       var Email = document.getElementById("txtemail").value;
       var Password = document.getElementById("txtpassword").value;
       var Confirmpass = document.getElementById("passwordconfirm").value;

         db = window.openDatabase("SoccerEarth", "2.0", "SoccerEarthDB", 2*1024*1024);
         db.transaction(function(tx) {
          NewUser(tx, Username, Firstname, Lastname, Email, Password, Confirmpass);
          }, errorRegistration, successRegistration);
          }

          function NewUser(tx, Username, Firstname, Lastname, Email, Password, Confirmpass) {
          var _Query = ("INSERT INTO SoccerEarth(UserName, FirstName, LastName, Email, Password, CPass) values ('"+ Username +"','"+ Firstname +"','"+ Lastname +"','"+ Email +"', '"+ Password +"', '"+ Confirmpass +"')");
           alert(_Query);
           tx.executeSql(_Query);
           }
           function errorRegistration(error) {
        navigator.notification.alert(error, null, "Got an error mate", "cool");
            }
           function successRegistration() {
           navigator.notification.alert("User data has been registered", null, "Information", "ok");
             $( ":mobile-pagecontainer" ).pagecontainer( "change", "#page4" );
         }

Answer 1

我删除了onclick="return registerUser(); return false;" 从输入按钮将其放置在submitHandler 。

为了防止提交表单，我添加了。

$('#form1').submit(function(e) {
    e.preventDefault();
})

 $(document).ready(function () { function registerUser(form) { var formdata = $(form).serializeArray() console.log(formdata); } $('#form1').submit(function (e) { e.preventDefault(); }).validate({ rules: { txtusername: { required: true }, txtfirstname: { required: true }, txtlastname: { required: true }, txtemail: { required: true }, txtpassword: { required: true }, passwordconfirm: { required: true } }, messages: { txtusername: { required: "Please enter your Username." }, txtfirstname: { required: "Please enter your First Name." }, txtlastname: { required: "Please enter your Last Name." }, txtemail: { required: "Please enter your Email." }, txtpassword: { required: "Please enter your Password." }, passwordconfirm: { required: "Please enter your password again." } }, errorPlacement: function (error, element) { error.appendTo(element.parent().prev()); }, submitHandler: function (form, user) { registerUser(form); return false; } }); }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.9/jquery.validate.min.js "></script> <form id="form1"> <div data-role="fieldcontainer"> <label for="txtusername" data-theme="d">Username:</label> <input type="text" id="txtusername" name="txtusername" data-theme="d" placeholder="Enter Username"/> </div> <div data-role="fieldcontainer"> <label for="txtfirstname" data-theme="d">First Name:</label> <input type="text" id="txtfirstname" name="txtfirstname" data-theme="d" placeholder="Enter First Name"/> </div> <div data-role="fieldcontainer"> <label for="txtlastname" data-theme="d">Last Name:</label> <input type="text" id="txtlastname" name="txtlastname" data-theme="d" placeholder="Enter Last Name"/> </div> <div data-role="fieldcontainer"> <label for="txtemail" data-theme="d">Email:</label> <input type="email" id="txtemail" name="txtemail" data-theme="d" placeholder="Enter Enter Email"/> </div> <div data-role="fieldcontainer"> <label for="txtpassword" data-theme="d">Password:</label> <input type="text" id="txtpassword" name="txtpassword" data-theme="d" placeholder="Enter Password"/> </div> <div data-role="fieldcontainer"> <label for="passwordconfirm" data-theme="d">Confirm Password:</label> <input type="text" id="passwordconfirm" name="passwordconfirm" data-theme="d" placeholder="Confirm password"/> </div> <br> <input type="submit" value="Register User"> </form>