Javascript突出显示所选范围按钮 [英] Javascript Highlight Selected Range Button

问题描述

我正在尝试为页面创建一个学习工具，允许用户选择页面上的任何文本并单击按钮。然后，此单击将使用黄色背景格式化所选文本。我可以在单个标签内部进行此工作，但如果选择范围跨越多个标签（例如，无序列表中的第一个LI以及第二个的一半），我将难以应用该样式。不幸的是，我不能在这里用一个跨度包装选择。

I'm attempting to create a study tool for a page that allows a user to select any text on the page and click a button. This click then formats the selected text with a yellow background. I can make this work inside of a single tag, but if the range of selection is across multiple tags (for instance, the first LI in an unordered list along with half of the second), I have difficulty applying the style. I can't just wrap the selection with a span here unfortunately.

基本上，我想要与 contentEditable相关联的效果和 execCommand 而不实际在页面上进行任何可编辑的操作，只需单击按钮即可将背景颜色应用于所选文本。

Basically, I want the effects associated with contentEditable and execCommand without actually making anything editable on the page except to apply a background color to the selected text with the click of a button.

我对jQuery解决方案持开放态度，发现此插件似乎简化了跨浏览器创建范围的能力，但我无法使用它将任何格式应用于所选范围。我可以从控制台看到它正在接受选择，但使用类似的东西：

I'm open to jQuery solutions, and found this plug-in that seems to simplify the ability to create ranges across browsers, but I was unable to use it to apply any formatting to the selected range. I can see from the console that it's picking up on the selection, but using something like:

var selected = $().selectedText();
$(selected).css("background-color","yellow");

无效。

任何帮助非常感谢我指向正确的方向。

Any help pointing me in the right direction would be greatly appreciated.

推荐答案

以下应该做你想要的。在非IE浏览器中，它打开 designMode ，应用背景颜色，然后再次关闭 designMode 。

The following should do what you want. In non-IE browsers it turns on designMode, applies a background colour and then switches designMode off again.

更新

已修复在IE 9中工作。

Fixed to work in IE 9.

function makeEditableAndHighlight(colour) {
    sel = window.getSelection();
    if (sel.rangeCount && sel.getRangeAt) {
        range = sel.getRangeAt(0);
    }
    document.designMode = "on";
    if (range) {
        sel.removeAllRanges();
        sel.addRange(range);
    }
    // Use HiliteColor since some browsers apply BackColor to the whole block
    if (!document.execCommand("HiliteColor", false, colour)) {
        document.execCommand("BackColor", false, colour);
    }
    document.designMode = "off";
}

function highlight(colour) {
    var range, sel;
    if (window.getSelection) {
        // IE9 and non-IE
        try {
            if (!document.execCommand("BackColor", false, colour)) {
                makeEditableAndHighlight(colour);
            }
        } catch (ex) {
            makeEditableAndHighlight(colour)
        }
    } else if (document.selection && document.selection.createRange) {
        // IE <= 8 case
        range = document.selection.createRange();
        range.execCommand("BackColor", false, colour);
    }
}

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