javascript 单击提交按钮将其值更改为其他内容
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/6226246/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Submit button clicking changing the value of it to another thing
提问by Nickool
maybe very easy! I'm php coder and I don't have experience in js but I must do this for one of my codes suppose I have sub1 in page after clicking it must be that sub1 but value now is sub2
也许很容易！我是 php 编码员，我没有 js 方面的经验，但我必须为我的一个代码执行此操作，假设单击后页面中有 sub1，它必须是那个 sub1，但现在的值是 sub2
<html>
<head>
<title>pharmacy</title>
</head>
<body>
<form method="post" action="pharmacy.php">
<?php
//some code
if(array_key_exists('update',$_POST)){
//somecode
}
?>
<input type="submit" name="update" value="<?php echo if(isset($_GET['update'])) ? 'Show' : 'Update' ?> ">
</form>
</body>
</html>
回答by Felix Kling
showas function name does not really make sense here (imo), but you could do:
show因为函数名称在这里没有意义（imo），但你可以这样做：
<input type="submit" name="sub" value="sub1" onclick="show(this)">
and
和
function show(element) {
element.value = 'sub2';
}
Important:
重要的：
But that will actually not solve your problem. As soon as you click the button, the form is submitted, meaning the browser initiates a new request and will load a new page. So every change you made the current page is lost anyway.
但这实际上并不能解决您的问题。一旦您单击按钮，表单就会被提交，这意味着浏览器会发起一个新请求并将加载一个新页面。因此，无论如何，您对当前页面所做的每项更改都会丢失。
The question is: What are you trying to do?
问题是：你想做什么？
It seems to me that you should change the value of the button on the server side. You have to keep track which form was submitted (or how often, I don't know what you are trying to do) and set the value of the button accordingly.
在我看来，您应该更改服务器端按钮的值。您必须跟踪提交了哪个表单（或多久提交一次，我不知道您要做什么）并相应地设置按钮的值。
Update:
更新：
I see several possibilities to solve this:
我看到了解决这个问题的几种可能性：
You could keep using JavaScript and send and get the data via Ajax. As you have no experience with JavaScript, I would say you have to learn more about JavaScript and Ajax first before you can use it.
You could add a GET parameter in your URL with which you can know which label to show for the button. Example:
<form method="post" action="?update=1">and
<input type="submit" name="sub" value="<?php echo isset($_GET['update']) ? 'Show' : 'Update' ?> ">Similar to 2, but use a session variable(and not a GET parameter) to keep track of the state.
您可以继续使用 JavaScript 并通过Ajax发送和获取数据。由于您没有使用 JavaScript 的经验，我想说您必须先了解有关 JavaScript 和 Ajax 的更多信息，然后才能使用它。
您可以在您的 URL 中添加一个 GET 参数，通过它您可以知道要为按钮显示哪个标签。例子：
<form method="post" action="?update=1">和
<input type="submit" name="sub" value="<?php echo isset($_GET['update']) ? 'Show' : 'Update' ?> ">类似于 2，但使用会话变量（而不是 GET 参数）来跟踪状态。
Update2:
更新2：
As you are already having $_POST['update']you don't need the URL parameter. It could just be:
正如您已经拥有的$_POST['update']那样，您不需要 URL 参数。它可能只是：
<html>
<head>
<title>pharmacy</title>
</head>
<body>
<form method="post" action="pharmacy.php">
<input type="submit" name="update" value="<?php echo isset($_POST['update']) ? 'Update' : 'Show'; ?> ">
</form>
</body>
</html>
回答by Pradeep
<html>
<head>
<title>test</title>
<script>
function show()
{
document.getElementById("sub").value= "sub2";
return true;
}
</script>
</head>
<body>
<form method="post">
<input type='submit' id="sub" name='sub' value="sub1" onclick="return show()">
</form>
</body>
</html>
回答by Niklas
This should do it
这应该做
function show(){
document.getElementsByName('sub')[0].value = 'sub2';
return false;
}
Edit:if you don't want it to submit the form, just add a return false, but then you'd need to change your onclickfrom your submit button to your forms onsubmit;
编辑：如果您不希望它提交表单，只需添加一个return false，但是您需要将onclick您的提交按钮更改为您的表单onsubmit；
