javascript 如何使用javascript在文本输入中获取html特殊字符
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How to use javascript to get html special characters in text input
提问by kli
I want to sent some html special character to text field and then later use javascript to get it back in its original format: like if I sent "&pi", it will shows "π" on the text input, and when I use javascript to get it back, I should get "&pi", but I only can get "π", not "&pi". Please help, my code is like the following:
我想将一些 html 特殊字符发送到文本字段，然后使用 javascript 将其恢复为原始格式：就像我发送“&pi”一样，它会在文本输入中显示“π”，当我使用 javascript 时拿回来，我应该得到“&pi”，但我只能得到“π”，而不是“&pi”。请帮忙，我的代码如下：
<script type="text/javascript">
function qpush(a) {
document.getElementById('input').value += a;
}
function show(a) {
alert(document.getElementById('input').value);
}
</script>
<input type="text" id="input" />
<input type="button" onclick="qpush('π');" value="π" />
<input type="button" onclick="show()" value="go" />
采纳答案by Lior
Depending on what you need the it for you could do one of 3 options:
根据您的需要，您可以执行以下 3 个选项之一：
use the javascript escape and unescape functions:
var escaped = escape('π') // escaped = "%u03C0" which unescape will turn back into π
If you have jQuery available it's html method might do the trick:
$('input').val().html()
This is a hack but will work: Save a copy of the value the way you want it returned on a 'data-' attribute of the input element, this will validate in html5 and won't break in other doctypes.
document.getElementById('input').setAttribute('data-originalValue', '&pi')
使用 javascript 转义和 unescape 函数：
var escaped = escape('π') // escaped = "%u03C0" unescape 将变回 π
如果您有可用的 jQuery，它的 html 方法可能会起作用：
$('输入').val().html()
这是一个 hack 但会起作用：以您希望它在输入元素的“data-”属性上返回的方式保存值的副本，这将在 html5 中验证并且不会在其他文档类型中中断。
document.getElementById('input').setAttribute('data-originalValue', '&pi')
回答by Quentin
The valueproperty will give you text, not HTML.
该value属性将为您提供文本，而不是 HTML。
You could try getAttribute('value')but since πand πare identically equivalent in HTML, a browser is entirely free to return πfor that too.
您可以尝试，getAttribute('value')但由于π和π在 HTML 中完全相同，因此浏览器也可以完全免费返回π。
Once the HTML has been converted into a DOM, there is no way to access the original HTML (short of downloading the HTML again with XHR and parsing the raw text of it yourself).
一旦将 HTML 转换为 DOM，就无法访问原始 HTML（除了使用 XHR 再次下载 HTML 并自己解析原始文本之外）。
If you want the data to be "π"then the HTML for it needs to be &pi;.
如果您希望数据是，"π"那么它的 HTML 需要是&pi;.
If you want that and the rendering on the button to be πthen you need:
如果你想要那个和按钮上的渲染，π那么你需要：
<button type="button" value="&pi;">π</button>
(Keeping in mind the various bugs that old-IE has with the button element)
（请记住旧 IE 对按钮元素的各种错误）
That will, of course, display πwhen you copy the value to the text input.
当然，π当您将值复制到文本输入时会显示。
回答by Christoph
Use this to replace all occurrences of the character:
使用它来替换所有出现的字符：
document.getElementById('input').value.replace(/π/g,"π");
