js网页禁止右键下载代码

    <script type="text/javascript">
        //禁用右键
        document.onkeydown = function() {
                var e = window.event || arguments[0];
                if (e.keyCode == 123) {
                    //    alert('禁止F12');
                    return false;
                } else if ((e.ctrlKey) && (e.shiftKey) && (e.keyCode == 73)) {
                    //    alert('禁止Ctrl+Shift+I');
                    return false;
                } else if ((e.ctrlKey) && (e.keyCode == 85)) {
                    //    alert('禁止Ctrl+u');
                    return false;
                } else if ((e.ctrlKey) && (e.keyCode == 83)) {
                    //    alert('禁止Ctrl+s');
                    return false;
                }
            }
            // 屏蔽鼠标右键
        document.oncontextmenu = function() {
            //alert('禁止右键');
            return false;
        }
    </script>
    <script type="text/javascript">
        ((function() {
            var callbacks = [],
                timeLimit = 50,
                open = false;
            setInterval(loop, 1);
            return {
                addListener: function(fn) {
                    callbacks.push(fn);
                },
                cancleListenr: function(fn) {
                    callbacks = callbacks.filter(function(v) {
                        return v !== fn;
                    });
                }
            }

            function loop() {
                var startTime = new Date();
                debugger;
                if (new Date() - startTime > timeLimit) {
                    if (!open) {
                        callbacks.forEach(function(fn) {
                            fn.call(null);
                        });
                    }
                    open = true;
                    window.stop();
                    alert('禁止查看');
                    window.location.reload();
                } else {
                    open = false;
                }
            }
        })())

        .addListener(function() {
            window.location.reload();
        });
        //禁止查看网页代码结束
    </script>