使用jQuery选中时，如何获取元素的常规属性？

Question

I have a textarea which I select using jQuery, and I want to find the position of the cursor within it. I've found that in normal JavaScript you can do it with .selectionStart , but doing $("#maintext").selectionStart results in undefined .

How can I do it?

Answer 1

selectionStart is native DOM property so try this:

var selStart = $('#maintext').get(0).selectionStart;

The reason for this happening is that $('#maintext') returns an array of jQuery wrapped DOM objects and in order to invoke a native method you need to get the underlying element.

Answer 2

In that situation there might be a case for simply doing:

document.getElementById("maintext").selectionStart

and not have the overhead of creating a new jQuery object.

Answer 3

In jQuery 1.6, you could use prop() . In older versions, attr() could be used.

$("#maintext").prop("selectionStart");

However, selectionStart and selectionEnd properties are not supported in IE < 9. I've published a cross-browser function to work round this in a few places on Stack Overflow (for example, here ), or you could use my jQuery plug-in for dealing with textarea/text input selections.