JS 一键复制

$(function(){
$("#btn_code").click(function(){
var code=$("#active_code").text();
copyToClipboard(code);
});
});
function copyToClipboard(maintext){
if (window.clipboardData){
window.clipboardData.setData("Text", maintext);
}else if (window.netscape){
try{
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
}catch(e){
alert("该浏览器不支持一键复制！\n请手工复制文本框链接地址～");
}
var clip = Components.classes['@mozilla.org/widget/clipboard;1'].createInstance(Components.interfaces.nsIClipboard);
if (!clip) return;
var trans = Components.classes['@mozilla.org/widget/transferable;1'].createInstance(Components.interfaces.nsITransferable);
if (!trans) return;
trans.addDataFlavor('text/unicode');
var str = new Object();
var len = new Object();
var str = Components.classes["@mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);
var copytext=maintext;
str.data=copytext;
trans.setTransferData("text/unicode",str,copytext.length*2);
var clipid=Components.interfaces.nsIClipboard;
if (!clip) return false;
clip.setData(trans,null,clipid.kGlobalClipboard);
}
alert("已经复制到剪贴板\n\n" + maintext);
}