前端js禁止鼠标右键及F12禁止查看源代码究竟为了什么？

前端js禁止鼠标右键及f12禁止查看源代码

html 在中，f12审查元素的情况下，大家都可以随机更改一部分页面的代码，注入恶意js等等，这种情况避免也不难，虽然还能看到一部分h5，但是无法修改。

一、屏蔽f12 审查元素

<script>
    document.onkeydown = function () {
        if (window.event && window.event.keycode == 123) {
            alert("f12被禁用");
            event.keycode = 0;
            event.returnvalue = false;
        }
        if (window.event && window.event.keycode == 13) {
            window.event.keycode = 505;
        }
        if (window.event && window.event.keycode == 8) {
            alert(str + "\n请使用del键进行字符的删除操作！");
            window.event.returnvalue = false;
        }
    }
</script>

二、屏蔽右键菜单

<script>
    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;
        }
    }

三、屏蔽粘贴

<script>
    document.onpaste = 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;
        }
    }
</script>

四、屏蔽复制

<script>
    document.oncopy = 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;
        }
    }
</script>


五、屏蔽剪切

<script>
    document.oncut = 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;
        }
    }

六、屏蔽选中

<script>
    document.onselectstart = 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;
        }
    }
</script>

（本文转自博客园的clark_kent，感谢经验分享！）