无法通过在 javascript 中使用表单名称来获取表单元素
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unable to get form elements by using form name in javascript
提问by bassnoodle
I am having an issue with accessing my form by it's name. When I use document.form[0].mylink.value it recognizes the value and outputs to the innerHTML that I specify. However, when I use document.myform.mylink.value it doesn't seem to recognize the form. I have tried this in chrome 6.0 and also firefox 3.6.3 and get the same result in both. I really need to be able to access my form values by using the form name (instead of document.form[0]), any ideas why document.myform.mylink.value doesn't work?
我在按名称访问我的表单时遇到问题。当我使用 document.form[0].mylink.value 时，它会识别值并输出到我指定的 innerHTML。但是，当我使用 document.myform.mylink.value 时，它似乎无法识别该表单。我已经在 chrome 6.0 和 firefox 3.6.3 中尝试过这个，并且在两者中都得到了相同的结果。我真的需要能够通过使用表单名称（而不是 document.form[0]）来访问我的表单值，任何想法为什么 document.myform.mylink.value 不起作用？
<form name="myform">
<table>
<tr><td valign="middle" align="center">
<div id="textResponse"></div>
</td></tr>
<tr><td height="30" valign="middle" align="center">
<input name="mylink" value="Enter a URL" size="31" />
</td></tr>
<tr><td valign="top" align="center">
<a href="javascript:submitForm2();">Click</a>
</td></tr>
</table>
</form>
<script type="text/javascript">
function submitForm2(){
//This one does NOT work:
my_link = document.myform.mylink.value;
//This one also does NOT work:
//my_link = document.forms['myform'].mylink.value;
//This one works:
//my_link = document.forms[0].mylink.value;
document.getElementById("textResponse").innerHTML="<p>"+my_link+"</p>";
}
</script>
回答by scunliffe
Technically what you have should work ok... the full syntax below should also work:
从技术上讲，您所拥有的应该可以正常工作……下面的完整语法也应该可以工作：
var my_link = document.forms['myform'].elements['mylink'].value;
If by chance your variable in your "real" code is "mylink"not"my_link"you will get failures in IE as it will auto-reference the form element, not the value you are trying to extract.
如果您的“真实”代码中的变量碰巧"mylink"不是，"my_link"您将在 IE 中失败，因为它会自动引用表单元素，而不是您尝试提取的值。
That all said, your code as posted... works just fine in Firefox/IE(demo here: http://jsfiddle.net/Ymg8W/)
话虽如此，您发布的代码……在 Firefox/IE 中运行良好（此处演示：http: //jsfiddle.net/Ymg8W/）
