复制文字后加上版权信息

function addLink() {
        var body_element = document.getElementsByTagName('body')[0];
        var selection;
        if (window.getSelection) {//DOM,FF,Webkit,Chrome,IE10
            selection = window.getSelection();
            console.log(selection)
            // alert("文字复制成功！若有文字残缺请用右键复制\n转载请注明出处：" + document.location.href);

        } else if (document.getSelection) {//IE10
            selection = document.getSelection();
            alert("文字复制成功！若有文字残缺请用右键复制\n转载请注明出处：" + document.location.href);

        } else if (document.selection) {//IE6+10-
            selection = document.selection.createRange().text;
            alert("文字复制成功！若有文字残缺请用右键复制\n转载请注明出处：" + document.location.href);
        } else {
            selection = "";
            alert("浏览器兼容问题导致复制失败！");
        }
        var pagelink = "<br /><br /> 转载请注明来源: <a href='" + document.location.href + "'>" + document.location.href + "</a>";

        var copy_text = selection + pagelink;
        var new_div = document.createElement('div');

        new_div.style.left = '-99999px';
        new_div.style.position = 'absolute';

        body_element.appendChild(new_div);
        new_div.innerHTML = copy_text;

        selection.selectAllChildren(new_div);

        window.setTimeout(function () {
            body_element.removeChild(new_div);
        }, 0);
    }

  
    document.body.oncopy = addLink;