JS里charCodeAt()和fromCharCode()方法拓展应用：加密与解密.html

<!DOCTYPE html>
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    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<p><textarea id="text1" name="textfield" cols="50" rows="5">钱庄王员外这个人怎么样?</textarea></p>
<input type="button" name="Button1" value="加密" onClick="text1.value = MySign.Encrypt(text1.value);">
<input type="button" name="Button2" value="解密" onClick="text1.value = MySign.UnEncrypt(text1.value);">

<script>
    //    JS实现客户端的网页加密解密技术，可用作选择性隐蔽展示。当然客户端的加密安全度是不能与服务器相提并论，肯定不能用于密码这类内容的加密，但对于一般级别的内容用作展示已经够了。
    //    JS加密与解密的解决方案有很多，本文则利用String对象的charCodeAt()方法和fromCharCode()方法对字符的ASCII编码进行获取和修改。
    //    加密,解密代码：
    var MySign = {
        //加密/解密次数
        num: 0,
        //加密
        Encrypt: function (Text) {
            this.num = this.num + 1;
            output = new String;
            alterText = new Array();
            varCost = new Array();
            TextSize = Text.length;
            for (i = 0; i < TextSize; i++) {
                idea = Math.round(Math.random() * 111) + 77;
                alterText[i] = Text.charCodeAt(i) + idea;
                varCost[i] = idea;
            }
            for (i = 0; i < TextSize; i++) {
                output += String.v(alterText[i], varCost[i]);
            }
            //text1.value = output;
            return output;
        },

        //解密
        UnEncrypt: function (Text) {
            if (this.num > 0) {
                this.num = this.num - 1;
                output = new String;
                alterText1 = new Array();
                varCost1 = new Array();
                TextSize = Text.length;
                for (i = 0; i < TextSize; i++) {
                    alterText[i] = Text.charCodeAt(i);
                    varCost[i] = Text.charCodeAt(i + 1);
                }
                for (i = 0; i < TextSize; i = i + 2) {
                    output += String.fromCharCode(alterText[i] - varCost[i]);
                }
                //text1.value = output;
                return output;
            }
        }
    };


    //测试代码
    var testString = "光头强，还不去砍树？";
    console.log(testString);

    var sign = MySign.Encrypt(testString); //凑妣o忕ｧ[還¬什³呯´硠S桲aﾁb
    var sign2 = MySign.UnEncrypt(sign); //光头强，还不去砍树？

    console.log(sign);
    console.log(sign2);

</script>

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</html>