是否可以通过编程检测<input type=text>元素中的插入符号位置?

我在这方面做了很多工作。以下内容适用于所有主要浏览器(包括IE6)的文本 <input> s和 <textarea> s和将在所有情况下工作,包括有前导和尾随空格时(这是许多解决方案(包括a-tools)崩溃的地方)。这个问题中有一些代码的背景: IE's document.selection.createRange doesn't include leading or trailing blank lines

作为我编写的jQuery input/textarea selection插件的一部分,您还可以获得以下内容,该插件尚未记录在案: http://code.google.com/p/rangyinputs/

function getInputSelection(el) {
    var start = 0, end = 0, normalizedValue, range,
        textInputRange, len, endRange;

    if (typeof el.selectionStart == "number" && typeof el.selectionEnd == "number") {
        start = el.selectionStart;
        end = el.selectionEnd;
    } else {
        range = document.selection.createRange();

        if (range && range.parentElement() == el) {
            len = el.value.length;
            normalizedValue = el.value.replace(/\r\n/g, "\n");

            // Create a working TextRange that lives only in the input
            textInputRange = el.createTextRange();
            textInputRange.moveToBookmark(range.getBookmark());

            // Check if the start and end of the selection are at the very end
            // of the input, since moveStart/moveEnd doesn't return what we want
            // in those cases
            endRange = el.createTextRange();
            endRange.collapse(false);

            if (textInputRange.compareEndPoints("StartToEnd", endRange) > -1) {
                start = end = len;
            } else {
                start = -textInputRange.moveStart("character", -len);
                start += normalizedValue.slice(0, start).split("\n").length - 1;

                if (textInputRange.compareEndPoints("EndToEnd", endRange) > -1) {
                    end = len;
                } else {
                    end = -textInputRange.moveEnd("character", -len);
                    end += normalizedValue.slice(0, end).split("\n").length - 1;
                }
            }
        }
    }

    return {
        start: start,
        end: end
    };
}

var el = document.getElementById("your_input");
var sel = getInputSelection(el);
alert(sel.start + ", " + sel.end);

是的,这是可能的。

如果你用

http://plugins.jquery.com/project/a-tools

祝你好运:)

编辑:请注意,光标通常被引用为“插入符号”,仅供参考;)