在内容上设置光标位置可编辑<div>

此解决方案适用于所有主流浏览器：

saveSelection()附加到 div 的 和 事件，并将所选内容保存到变量 。onmouseuponkeyupsavedRange

restoreSelection()附加到 div 的事件，并重新选择保存在 中的选择。onfocussavedRange

这可以完美地工作，除非您希望在用户单击div时恢复选择（这有点不直观，因为通常您希望光标转到您单击的位置，但为了完整性而包含代码）

为了实现这一点，和 事件被函数取消，该函数是用于取消事件的跨浏览器函数。该函数还运行该函数，因为当单击事件被取消时，div 不会接收焦点，因此除非运行此函数，否则根本不选择任何内容。onclickonmousedowncancelEvent()cancelEvent()restoreSelection()

该变量存储它是否处于焦点中，并更改为“false”和“true”。这允许仅在 div 不在焦点时取消单击事件（否则您将根本无法更改选择）。isInFocusonbluronfocus

如果您希望在通过单击对 div 进行聚焦时更改选择，而不是恢复选择（并且仅当焦点以编程方式使用或类似方式分配给元素时，则只需删除 and 事件即可。在这些情况下，事件和 和 函数也可以安全地删除。onclickdocument.getElementById("area").focus();onclickonmousedownonbluronDivBlur()cancelEvent()

如果要快速测试，则将此代码直接放入html页面的正文中，则应有效：

<div id="area" style="width:300px;height:300px;" onblur="onDivBlur();" onmousedown="return cancelEvent(event);" onclick="return cancelEvent(event);" contentEditable="true" onmouseup="saveSelection();" onkeyup="saveSelection();" onfocus="restoreSelection();"></div>
<script type="text/javascript">
var savedRange,isInFocus;
function saveSelection()
{
    if(window.getSelection)//non IE Browsers
    {
        savedRange = window.getSelection().getRangeAt(0);
    }
    else if(document.selection)//IE
    { 
        savedRange = document.selection.createRange();  
    } 
}

function restoreSelection()
{
    isInFocus = true;
    document.getElementById("area").focus();
    if (savedRange != null) {
        if (window.getSelection)//non IE and there is already a selection
        {
            var s = window.getSelection();
            if (s.rangeCount > 0) 
                s.removeAllRanges();
            s.addRange(savedRange);
        }
        else if (document.createRange)//non IE and no selection
        {
            window.getSelection().addRange(savedRange);
        }
        else if (document.selection)//IE
        {
            savedRange.select();
        }
    }
}
//this part onwards is only needed if you want to restore selection onclick
var isInFocus = false;
function onDivBlur()
{
    isInFocus = false;
}

function cancelEvent(e)
{
    if (isInFocus == false && savedRange != null) {
        if (e && e.preventDefault) {
            //alert("FF");
            e.stopPropagation(); // DOM style (return false doesn't always work in FF)
            e.preventDefault();
        }
        else {
            window.event.cancelBubble = true;//IE stopPropagation
        }
        restoreSelection();
        return false; // false = IE style
    }
}
</script>

这与基于标准的浏览器兼容，但在IE中可能会失败。我将其作为起点提供。IE 不支持 DOM 范围。

var editable = document.getElementById('editable'),
    selection, range;

// Populates selection and range variables
var captureSelection = function(e) {
    // Don't capture selection outside editable region
    var isOrContainsAnchor = false,
        isOrContainsFocus = false,
        sel = window.getSelection(),
        parentAnchor = sel.anchorNode,
        parentFocus = sel.focusNode;

    while(parentAnchor && parentAnchor != document.documentElement) {
        if(parentAnchor == editable) {
            isOrContainsAnchor = true;
        }
        parentAnchor = parentAnchor.parentNode;
    }

    while(parentFocus && parentFocus != document.documentElement) {
        if(parentFocus == editable) {
            isOrContainsFocus = true;
        }
        parentFocus = parentFocus.parentNode;
    }

    if(!isOrContainsAnchor || !isOrContainsFocus) {
        return;
    }

    selection = window.getSelection();

    // Get range (standards)
    if(selection.getRangeAt !== undefined) {
        range = selection.getRangeAt(0);

    // Get range (Safari 2)
    } else if(
        document.createRange &&
        selection.anchorNode &&
        selection.anchorOffset &&
        selection.focusNode &&
        selection.focusOffset
    ) {
        range = document.createRange();
        range.setStart(selection.anchorNode, selection.anchorOffset);
        range.setEnd(selection.focusNode, selection.focusOffset);
    } else {
        // Failure here, not handled by the rest of the script.
        // Probably IE or some older browser
    }
};

// Recalculate selection while typing
editable.onkeyup = captureSelection;

// Recalculate selection after clicking/drag-selecting
editable.onmousedown = function(e) {
    editable.className = editable.className + ' selecting';
};
document.onmouseup = function(e) {
    if(editable.className.match(/\sselecting(\s|$)/)) {
        editable.className = editable.className.replace(/ selecting(\s|$)/, '');
        captureSelection();
    }
};

editable.onblur = function(e) {
    var cursorStart = document.createElement('span'),
        collapsed = !!range.collapsed;

    cursorStart.id = 'cursorStart';
    cursorStart.appendChild(document.createTextNode('—'));

    // Insert beginning cursor marker
    range.insertNode(cursorStart);

    // Insert end cursor marker if any text is selected
    if(!collapsed) {
        var cursorEnd = document.createElement('span');
        cursorEnd.id = 'cursorEnd';
        range.collapse();
        range.insertNode(cursorEnd);
    }
};

// Add callbacks to afterFocus to be called after cursor is replaced
// if you like, this would be useful for styling buttons and so on
var afterFocus = [];
editable.onfocus = function(e) {
    // Slight delay will avoid the initial selection
    // (at start or of contents depending on browser) being mistaken
    setTimeout(function() {
        var cursorStart = document.getElementById('cursorStart'),
            cursorEnd = document.getElementById('cursorEnd');

        // Don't do anything if user is creating a new selection
        if(editable.className.match(/\sselecting(\s|$)/)) {
            if(cursorStart) {
                cursorStart.parentNode.removeChild(cursorStart);
            }
            if(cursorEnd) {
                cursorEnd.parentNode.removeChild(cursorEnd);
            }
        } else if(cursorStart) {
            captureSelection();
            var range = document.createRange();

            if(cursorEnd) {
                range.setStartAfter(cursorStart);
                range.setEndBefore(cursorEnd);

                // Delete cursor markers
                cursorStart.parentNode.removeChild(cursorStart);
                cursorEnd.parentNode.removeChild(cursorEnd);

                // Select range
                selection.removeAllRanges();
                selection.addRange(range);
            } else {
                range.selectNode(cursorStart);

                // Select range
                selection.removeAllRanges();
                selection.addRange(range);

                // Delete cursor marker
                document.execCommand('delete', false, null);
            }
        }

        // Call callbacks here
        for(var i = 0; i < afterFocus.length; i++) {
            afterFocus[i]();
        }
        afterFocus = [];

        // Register selection again
        captureSelection();
    }, 10);
};