是否有Internet Explorer批准的selectionStart和selectionEnd的替代品？ [英] Is there an Internet Explorer approved substitute for selectionStart and selectionEnd?

问题描述

找出在真实浏览器中选择的内容非常简单：

Finding out what's selected in real browsers is as simple as:

var range = {
  start: textbox.selectionStart,
  end: textbox.selectionEnd
}

但IE，as通常，不明白。什么是最好的跨浏览器方式呢？

But IE, as usual, doesn't understand. What's the best cross-browser way to do this?

推荐答案

我会再发布一次这个函数，看看这个问题从另一个链接到另一个。

I'll post this function for another time, seeing as this question got linked to from another one.

以下内容将在所有浏览器中完成，处理所有新行问题而不会严重影响性能。我在一些toing和我已经相信它是最好的这种功能。

The following will do the job in all browsers and deals with all new line problems without seriously compromising performance. I've arrived at this after some toing and froing and now I'm pretty convinced it's the best such function around.

更新

此函数确实假设textarea / input具有焦点，因此您可能需要在调用之前调用textarea的 focus（）方法。

This function does assume the textarea/input has focus, so you may need to call the textarea's focus() method before calling it.

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");
el.focus();
var sel = getInputSelection(el);
alert(sel.start + ", " + sel.end);

这篇关于是否有Internet Explorer批准的selectionStart和selectionEnd的替代品？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！