我正在处理一个包含多个文本框和提交按钮的Web表单。单击提交按钮时，我应该验证所需的字段都有输入，并且age字段只是数字。例如，用户可以输入56，但56岁，不应该被接受。如果用户输入无效输入或将必填字段留空，则相应文本框周围的边框应变为红色。
但是，当我的代码写入时，无论输入如何，所有必填字段都会变为红色。任何想法我如何解决这个问题，并使页面遵循我列出的几条规则？
最新代码
<html>
<head>
<title>Project 4</title>
<style type="text/css">
body {
background-color: black;
color: blue;
text-align: center;
border: 2px double blue;
}
</style>
</head>
<body>
<h1>Welcome to my Web Form!</h1>
<p>
Please fill out the following information.<br>
Please note that fields marked with an asterisk (*) are required.
</p>
<form name="myForm" id="myForm" onsubmit="return validateForm()">
*Last Name: <br>
<input type="text" id="lastname">
<br>
First Name: <br>
<input type="text" id="firstname">
<br>
*Hobbies (separate each hobby with a comma): <br>
<input type="text" id="hobbies">
<br>
Pets:
<div id="petsContainer">
<input type="text" id="pets">
<input type="button" id="addPet" value="Add Pet">
</div>
<br>
Children:
<div id="childContainer">
<input type="text" id="children">
<input type="button" id="addKid" value="Add Child">
</div>
<br>
*Address: <br>
<input type="text" id="address">
<br>
*Phone Number:<br>
<input type="text" id="phone">
<br>
*Age: <br>
<input type="text" id="age">
<br>
<input type="submit" value="Submit">
</form>
<script type="text/javascript">
var validatePhoneOnKeyUpAttached = false;
var validateLNameOnKeyUpAttached = false;
var validateHobbiesOnKeyUpAttached = false;
var validateAddressOnKeyUpAttached = false;
var validateAgeOnKeyUpAttached = false;
function validateForm() {
if(!validatePhoneOnKeyUpAttached) {
document.getElementById("phone").onkeyup = checkPhone;
validatePhoneOnKeyUpAttached = true;
}
else if(!validateLNameOnKeyUpAttached) {
document.getElementById("lastname").onkeyup = checkEmpty;
validateLNameOnKeyUpAttached = true;
}
else if(!validateHobbiesOnKeyUpAttached) {
document.getElementById("hobbies").onkeyup = checkEmpty;
validateHobbiesOnKeyUpAttached = true;
}
else if(!validateAddressOnKeyUpAttached) {
document.getElementById("address").onkeyup = checkEmpty;
validateAddressOnKeyUpAttached = true;
}
else if(!validateAgeOnKeyUpAttached) {
document.getElementById("age").onkeyup = checkEmpty;
document.getElementById("age").onkeyup = checkAge;
validateAgeOnKeyUpAttached = true;
}
return checkEmpty() && checkPhone() && checkAge();
}
function checkPhone() {
var phone = document.forms["myForm"]["phone"].value;
var phoneNum = phone.replace(/[^\d]/g, '');
if(phoneNum.length > 6 && phoneNum.length < 11) {
document.getElementById("phone").style.borderColor="transparent";
return true;
}
else if(phoneNum.length < 7 || phoneNum.length > 10) {
document.getElementById("phone").style.borderColor="red";
return false;
}
}
function checkEmpty() {
var lname = document.forms["myForm"]["lastname"].value;
var pNum = document.forms["myForm"]["phone"].value;
var hobs = document.forms["myForm"]["hobbies"].value;
var live = document.forms["myForm"]["address"].value;
var yr = document.forms["myForm"]["age"].value;
document.getElementById("lastname").style.borderColor = (lname == "") ? "red" : "transparent";
document.getElementById("hobbies").style.borderColor = (hobs == "") ? "red" : "transparent";
document.getElementById("phone").style.borderColor = (pNum == "") ? "red" : "transparent";
document.getElementById("address").style.borderColor = (live == "") ? "red" : "transparent";
document.getElementById("age").style.borderColor = (yr == "") ? "red" : "transparent";
}
function checkAge() {
var age = document.getElementById("age").value;
if(isNan(age)) {
return false;
}
else {
document.getElementById("age").style.borderColor="red";
return true;
}
}
document.getElementById("addPet").onclick=function() {
var div = document.getElementById("petsContainer");
var input = document.createElement("input");
input.type = "text";
input.name = "pats[]";
div.appendChild(document.createElement("br"));
div.appendChild(input);
}
document.getElementById("addKid").onclick=function() {
var div = document.getElementById("childContainer");
var input = document.createElement("input");
input.type = "text";
input.name = "child[]";
div.appendChild(document.createElement("br"));
div.appendChild(input);
}
</script>
</body>
</html>
我目前遇到的问题是，当我点击提交按钮时，所有字段都会瞬间变为红色，但之后会返回常规颜色并且输入将被删除。关于如何解决这个问题的任何想法？
答案 0 :(得分：1)
通过在单个代码块中包含所有borderColor =“red”语句，您将该样式应用于所有输入，即使其中只有一个未通过验证。您需要将每个语句分开，以便它仅适用于验证失败的各个字段：
document.getElementById("lastname").style.borderColor = (lname == "") ? "red" : "transparent";
document.getElementById("phone").style.borderColor = (pNum == "") ? "red" : "transparent";
...
另外，我正在使用三元运算符? :来清理代码。这些语句将取代您编写的if-else块。
答案 1 :(得分：0)
我正在使用以下javascript函数来验证我的表单变量。希望这些对你有所帮助。
var W3CDOM = (document.getElementsByTagName && document.createElement);
window.onload = function () {
document.forms[0].onsubmit = function () {
return validate()
}
}
function validate() {
validForm = true;
firstError = null;
errorstring = '';
var x = document.forms[0].elements;
for (var i = 0;i < x.length;i++) {
if (!x[i].value) {
validForm = false;
writeError(x[i], 'This field is required');
}
}
// This can be used to validate input type Email values
/* if (x['email'].value.indexOf('@') == -1) {
validForm = false;
writeError(x['email'],'This is not a valid email address');
}
*/
if (!W3CDOM)
alert(errorstring);
if (firstError)
firstError.focus();
return validForm;
}
function writeError(obj, message) {
validForm = false;
//if (obj.hasError) return false;
if (W3CDOM) {
obj.className += ' error';
obj.onchange = removeError;
var sp = document.createElement('span');
sp.className = 'error';
sp.appendChild(document.createTextNode(message));
obj.parentNode.appendChild(sp);
obj.hasError = sp;
} else {
errorstring += obj.name + ': ' + message + '\n';
obj.hasError = true;
}
if (!firstError)
firstError = obj;
return false;
}
function removeError() {
this.className = this.className.substring(0, this.className.lastIndexOf(' '));
this.parentNode.removeChild(this.hasError);
this.hasError = null;
this.onchange = null;
}
您可以在表单提交后立即调用验证，如下所示。
<form name="loginForm" action="do.login" method="POST" class="form" onsubmit="return validate();">