如何获取文本区域中的选择的开始和结束点？ [英] How to get the start and end points of selection in text area?

问题描述

我想在文本字段或文本区域中获取所选范围的光标开始和结束位置。我试过很多功能在各种论坛。但是当选择的最后一个字符是一个新的行字符JavaScript忽略它在IE6。

解决方案

修订答案，2010年9月5日 b

要考虑到尾随换行符在IE中是棘手的，我没有看到任何解决方案。但是，有可能。以下是我之前在这里发布的一个新版本。

请注意，textarea必须有焦点，这个函数在IE中正常工作。如果有疑问，先调用textarea的 focus（）方法。

  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\\\
 / g，\\\
）; 
 
 //创建一个只在输入中存在的工作TextRange 
 textInputRange = el.createTextRange（）; 
 textInputRange.moveToBookmark（range.getBookmark（））; 
 
 //检查选择的开始和结束是否在输入的最后
 //，因为moveStart / moveEnd不返回我们想要的结果
 / /在这些情况下
 endRange = el.createTextRange（）; 
 endRange.collapsed（false）; 
 
 if（textInputRange.compareEndPoints（StartToEnd，endRange）> -1）{
 start = end = len; 
} else {
 start = -textInputRange.moveStart（character，-len）; 
 start + = normalizedValue.slice（0，start）.split（\\\
）。 
 
 if（textInputRange.compareEndPoints（EndToEnd，endRange）> -1）{
 end = len; 
} else {
 end = -textInputRange.moveEnd（character，-len）; 
 end + = normalizedValue.slice（0，end）.split（\\\
）。 
} 
} 
} 
} 
 
 return {
 start：start，
 end：end 
} ; 
} 
  

i want to get the cursor start and end position of a selected range in a text-field or text-area. i tried lot of functions in various forums. but when the last character of the selection is a new line character JavaScript ignore it in IE6. any one having idea ?

解决方案

Revised answer, 5 September 2010

To account for trailing line breaks is tricky in IE, and I haven't seen any solution that does this. It is possible, however. The following is a new version of what I previously posted here.

Note that the textarea must have focus for this function to work properly in IE. If in doubt, call the textarea's focus() method first.

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
    };
}

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