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在我的 html 表单中，当一个字段留空并执行 Javascript 时，会使用 innerHTML 显示一条错误消息。但是，在为该字段使用允许的输入后，另一个字段为空白，该消息不会消失。如果我刷新页面，字段中的所有信息都会保留，但 innerHTML 消息会消失。单击计算按钮并执行Javascript后，有没有办法使错误消息消失？就像让它重新检查并以某种方式将消息带走一样。

这是我的html代码：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
    <title>The Happy Hoppin' Hotel</title>
    <link type="text/css" rel="stylesheet" href="happyhoppin_skeleton.css" />
    <script src="happyhoppin_skeleton.js" language="javascript" type="text/javascript"></script> 
  </head>
    <body>
        <form>
            <h1>The Happy Hoppin' Hotel Checkout Page</h1>
            <p>Fill out the form below to calculate balance due</p>
            Guest ID Number: <input type="text" id="custID" /><div id="guestID"> </div>
            Room Type: 
            <select id="roomType" />
                <option></option>
                <option>Double</option>
                <option>Single</option>
                <option>Parlor</option>
            </select><div id="room"> </div>
            Length of Stay: <input type="text" id="stayLength" name="" /><div id="stay"> </div>
            Number of Drinks: <input type="text" id="drinkNum" name="" /><div id="drink"> </div>
            Number of Towels: <input type="text" id="towelNum" name="" /><div id="towel"> </div>
            Number of Flushes: <input type="text" id="flushNum" name="" /><div id="flush"> </div>
            Bug Complaints?:  <label><br>
            <input type="radio" id="radio" name="bugComplaint" value="Yes" onclick="getCheckedRadio(this)" />Yes<br>
            <input type="radio" id="radio" name="bugComplaint" value="No" onclick="getCheckedRadio(this)" />No

            <div id="comments">Customer Comments: 
            <textarea name="customerComment" id="comments" onFocus="this.value=''" value="Make me disappear" cols="50" rows="5">Enter your comments here...</textarea> 
            </div>
            <input type="button" onclick="calculateFinalBill()" value="Calculate">
        </form>
    </body> 
</html>

这是我的 Javascript 代码：

const doublePrice = 150;
const singlePrice = 100;
const parlorPrice = 80;
const drinkPrice = 5;
const towelPrice = 3;
const flushPrice = 1;

var custID;
var roomPrice;
var stayLength;
var drinkNum;
var towelNum;
var flushNum;
var totalDue;
var subtotal;
var roomType;
var bugDiscount;

function calculateFinalBill() {
    validateForm();
    if(roomType == "Double"){
    roomPrice = doublePrice;
    }

    if(roomType == "Single"){
    roomPrice = singlePrice;
    }

    if(roomType == "Parlor"){
    roomPrice = parlorPrice;
    }

    roomTotal = roomPrice * stayLength

    towelTotal = towelPrice * towelNum

    flushTotal = flushPrice * flushNum

    drinkTotal = drinkPrice * drinkNum

    subtotal = roomTotal + towelTotal + flushTotal + drinkTotal

    totalDue = subtotal - bugDiscount

    displayBill();
}

function getCheckedRadio(which){
var bugValue = which.value;
    if (bugValue == "No"){
    bugDiscount = 0;
    }
    if (bugValue == "Yes"){
    bugDiscount = 20;
    }
}

function validateForm(){
custID = parseInt(document.getElementById("custID").value);
if(isNaN(custID)){
    document.getElementById('guestID').innerHTML="*Guest ID must be a number"
    throw "stop execution";
}

if(custID <= 0){
    document.getElementById('guestID').innerHTML="*Guest ID must be greater than zero"
    throw "stop execution";
}

roomType = document.getElementById("roomType").value;
if(roomType == ""){
    document.getElementById('room').innerHTML="*Room type must be selected"
    throw "stop execution";
}

stayLength = parseInt(document.getElementById("stayLength").value);
if(isNaN(stayLength)){
    document.getElementById('stay').innerHTML="*Length of Stay must be a number"
    throw "stop execution";
    }
if(stayLength < 0){
    document.getElementById('stay').innerHTML="*Length of Stay must be greater than zero"
    throw "stop execution";
}

drinkNum = parseInt(document.getElementById("drinkNum").value);
if(isNaN(drinkNum)){
    document.getElementById('drink').innerHTML="*Number of Drinks must be a number"
    throw "stop execution";
    }
if(drinkNum < 0 || drinkNum > 25){
    document.getElementById('drink').innerHTML="*Number of Drinks must be 0-25"
    throw "stop execution";
}

towelNum = parseInt(document.getElementById("towelNum").value);
if(isNaN(towelNum)){
    document.getElementById('towel').innerHTML="*Number of Towels must be a number"
    throw "stop execution";
    }
if(towelNum < 0){
    document.getElementById('towel').innerHTML="*Number of Towels must be zero or greater"
    throw "stop execution";
}

flushNum = parseInt(document.getElementById("flushNum").value);
if(isNaN(flushNum)){
    document.getElementById('flush').innerHTML="*Number of Flushes must be a number"
    throw "stop execution";
    }
if(flushNum < 0){
    document.getElementById('flush').innerHTML="*Number of Flushes must be zero or greater"
    throw "stop execution";
}

customerComment = document.getElementById("customerComment");
}

function displayBill(){
var newPage =  "<html><head><title>Billing Summary</title></head>"; //Add CSS after title
    newPage += "<body><h1>Happy Hoppin Hotel</h1>";
    newPage += "<h2>Guest Billing Summary</h2>";
    newPage += "Guest Identification: " + custID;
    newPage += "<br />";
    newPage += "Room Type: " + roomType;
    newPage += "<br />";
    newPage += "Length of Stay: " + stayLength;
    newPage += "<br />";
    newPage += "Room Charge: $" + roomTotal;
    newPage += "<br />";
    newPage += "Drink Charge: $" + drinkTotal;
    newPage += "<br />";
    newPage += "Towel Charge: $" + towelTotal;
    newPage += "<br />";
    newPage += "Flushing Charge: $" + flushTotal;
    newPage += "<br />";
    newPage += "Subtotal: $" + subtotal;
    newPage += "<br />";
    if(bugDiscount != 0)
    {
    newPage += "Discount: $" + bugDiscount;
    newPage += "<br />";
    }
    newPage += "Total Due: $" + totalDue;
    newPage += "<br />";
    newPage += "Come back and visit us again at the Happy Hoppin' Hotel"

var j = window.open('','','width=400,height=500');
j.document.write(newPage);
j.document.close();

}

这可能有助于直观http://jsbin.com/ifuxiv/1/edit 如果您单击计算，在访客 ID 中输入一个值，然后再次单击计算，您将看到“访客 ID 必须是数字”消息不会消失。

如果我的问题令人困惑或需要任何其他信息，请在拒绝我的问题之前询问。谢谢。

4

1 回答 1

1

这可以通过在验证开始时重置错误消息来简单地解决：

document.getElementById('guestID').innerHTML='';
document.getElementById('room').innerHTML='';
document.getElementById('stay').innerHTML='';
document.getElementById('drink').innerHTML='';
/// and so on.

然而，最好以更干燥的方式处理这个问题（不要重复自己），或者创建用于设置每个错误消息的通用方法，或者至少存储对每个错误输出元素的 var 引用，var gID = document.getElementById('guestID');这意味着你可以轻松地写gID.innerHTML在任何你需要的地方，并且可以节省重新搜索 DOM。

于 2013-04-14T01:40:52.603 回答