textarea屏蔽文本粘贴功能

//屏蔽右键菜单
document.oncontextmenu = function (event) {
    if (window.event) {
        event = window.event;
    }
    try {
        var the = event.srcElement;
        if (!((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) {
            return false;
        }
        return true;
    } catch (e) {
        return false;
    }
};
//屏蔽Ctrl+V
document.onkeydown=function(ev){
    var ev=window.event||ev;
    var code=ev.keyCode||ev.which||ev.charCode;
    if((ev.ctrlKey) && (code==86)){
        ev.returnValue=false;
        //alert("Ctrl+V被禁止啦！");
    }
};