js虽然有第三方支持的GBK工具，但是小程序没有；而我开发中又需要进行格式的转化，就依据前人的经验做了一份出来。

分为两部分：Decode.js和Encode.js。分别是GBK格式的二进制文件转化为UTF-8的String和反转。

import Encoder from "./encode/Encoder";

import Decoder from "./encode/Decoder";

//实现参考例子

var message = "减肥是一件困难的事情";

//UTF-8转GBK

var gbkArray = Encoder.hexstrToArray(Encoder.stringToGbkHexstr(message));

console.log("gbkArray>>" + gbkArray);

//GBK转UTF-8

var utfStr = Decoder.GBKHexstrToString(Decoder.binaryarrayToHexstr(gbkArray));

console.log("utfStr>>" + utfStr);

文件下载地址：GITHUB

Decoder.js 因为太长，所以只贴出关键代码

/**

* GBK二进制编码集合，转换成标准的javascript String输出

*/

function GBKHexstrToString(input){

if (input.length % 2 !== 0) {

throw new Error('错误的输入:' + input);

}

var output = '';

for (var offset = 0; offset < input.length;) {

var value = input.substring(offset, offset + 2);

offset += 2;

if (value.charAt(0) < '8') {

output += String.fromCharCode(parseInt(value, 16));

continue;

} else {

var low = input.substring(offset, offset + 2);

offset += 2;

value = value + low;

output += String.fromCharCode(GBKTable[parseInt(value, 16)]);

}

}

return output;

}

/**

* 将binaryArray转化成hexString

*

* @param array 输入的binaryArray

* @returns {string} 输出的hexString

*/

function binaryarrayToHexstr (array) {

var output = '';

array.forEach(function (i) {

output += oneByteIntToHex(i);

});

return output.toUpperCase();

};

/***

* 将一个字节的整型转换成16进制

*

* @private

* @param i

* @returns {string}

*/

function oneByteIntToHex (i) {

var output = '';

i = parseInt(i);

output += (i >> 4 & 0x0f).toString(16);

output += (i & 0x0f).toString(16);

return output.toUpperCase();

};

module.exports = {

GBKHexstrToString: GBKHexstrToString,

oneByteIntToHex: oneByteIntToHex,

binaryarrayToHexstr: binaryarrayToHexstr

}

Encode.js

/**

* 标准的Javascript String转换成GBK二进制编码集合输出

* 支持Array/String输入，异步

*/

function stringToGbkHexstr (input) {

var output = '';

for (var offset = 0; offset < input.length; offset++) {

var code = input.charCodeAt(offset) & 0xffff;

if (code <= 0xFF) {

output += intToHex(code);

} else {

output += GBKTable[code];

}

}

return output;

}

/***

* 将一个字节的整型转换成16进制

*

* @private

* @param i

* @returns {string}

*/

function intToHex (i) {

var output = '';

for (; i != 0; i = i >> 8) {

output = oneByteIntToHex(i & 0xff) + output;

}

return output.toUpperCase();

}

/***

* 将一个字节的整型转换成16进制

*

* @private

* @param i

* @returns {string}

*/

function oneByteIntToHex (i) {

var output = '';

i = parseInt(i);

output += (i >> 4 & 0x0f).toString(16);

output += (i & 0x0f).toString(16);

return output.toUpperCase();

};

/**

* HexStr 转 ArrayBuffer

*/

function hexstrToArray (input) {

if (input.length % 2 != 0) {

throw new Error("not support length:" + input.length);

}

var output = new Array();

var index = 0, offset = 0;

for (; offset < input.length;) {

var expected = input.substring(offset, offset + 1);

var hi = (parseInt(expected, 16) & 0xff) << 4;

offset++;

expected = input.substring(offset, offset + 1);

var lo = parseInt(expected, 16) & 0xff;

output[index] = hi + lo;

index++;

offset++;

}

return output;

}

module.exports = {

stringToGbkHexstr: stringToGbkHexstr,

intToHex: intToHex,

hexstrToArray: hexstrToArray

}