以下是asp.net web表单:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h2 id="first">Enter 1st Number<input type="text" /></h2>
<h2 id ="second">Enter 2nd Number<input type="text" /></h2>
<h2 id="third">Enter 3rd Number<input type="text" /></h2>
<button onclick="test()">Sublit</button>
</div>
<p id="sum"></p>
</form>
<script src="JavaScript.js"></script>
这是javascript文件:
function test()
{
var num1 = parseInt(document.getElementById("first").value)
var num2 = parseInt(document.getElementById("second").value)
var num3 = parseInt(document.getElementById("third").value)
var z = num1 + num2 + num3
document.getElementById("sum").innerHTML = z
}
当我按下submit按钮时,页面上没有显示sum of three no。它只显示NAN一次,然后就消失了。我开始学习.net。请帮帮我
发布于 2018-06-24 00:15:02
您将id
添加到h
标记中,但是您需要将id
属性添加到输入元素中,以便使用document.getElementById
获取它的值。
另外按钮的默认类型是submit
,你需要阻止默认行为或者改变button type='button'
function test(e) {
e.preventDefault()
var num1 = parseInt(document.getElementById("first").value)
var num2 = parseInt(document.getElementById("second").value)
var num3 = parseInt(document.getElementById("third").value)
var z = num1 + num2 + num3
document.getElementById("sum").innerHTML = z
}
<form id="form1" runat="server">
<div>
<h2>Enter 1st Number<input id="first" type="text" /></h2>
<h2>Enter 2nd Number<input id="second" type="text" /></h2>
<h2>Enter 3rd Number<input id="third" type="text" /></h2>
<button onclick="test(event)">Sublit</button>
</div>
<p id="sum"></p>
</form>
发布于 2018-06-24 00:15:22
function test() {
var num1 = parseInt(document.getElementById("first").value)
var num2 = parseInt(document.getElementById("second").value)
var num3 = parseInt(document.getElementById("third").value)
var z = num1 + num2 + num3
document.getElementById("sum").innerHTML = z
}
<form id="form1" runat="server">
<div>
<h2 >Enter 1st Number<input type="text" id="first" /></h2>
<h2 >Enter 2nd Number<input type="text" id ="second" /></h2>
<h2 >Enter 3rd Number<input type="text" id="third" /></h2>
<button onclick="test()">Sublit</button>
</div>
<p id="sum"></p>
</form>
您需要将id提供给inputs
,而不是<h2>
元素将解决此问题
发布于 2018-06-24 00:24:34
首先,您需要在input中设置id,而不是在h2标记中。
<h2 >Enter 1st Number<input type="text" id="first" /></h2>
<h2 >Enter 2nd Number<input type="text" id ="second" /></h2>
<h2 >Enter 3rd Number<input type="text" id="third"/></h2>
对于消失的问题,使用输入类型的按钮而不是按钮标签来防止重新加载。
<input type="button" value="Submit" onclick="test()">
https://stackoverflow.com/questions/51002895
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