go utf-8轉其他編碼

package main

import (
"golang.org/x/text/transform"
"bytes"
"golang.org/x/text/encoding/charmap"
"golang.org/x/text/encoding/simplifiedchinese"
"io/ioutil"
"fmt"
"math/rand"
"time"
)

func main() {
rand.Seed(time.Now().Unix())
fmt.Println(string(convert(rand.Intn(47),[]byte("golang學習"))))
}

func convert(i int, s []byte) ([]byte) {
var reader *transform.Reader
switch i {
case 1:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_1.NewDecoder())
case 2:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_2.NewDecoder())
case 3:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_3.NewDecoder())
case 4:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_4.NewDecoder())
case 5:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_5.NewDecoder())
case 6:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_6.NewDecoder())
case 7:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_7.NewDecoder())
case 8:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_8.NewDecoder())
case 9:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_9.NewDecoder())
case 10:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_10.NewDecoder())
case 11:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_13.NewDecoder())
case 12:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_14.NewDecoder())
case 13:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_15.NewDecoder())
case 14:
reader = transform.NewReader(bytes.NewReader(s), charmap.ISO8859_16.NewDecoder())
case 15:
reader = transform.NewReader(bytes.NewReader(s), charmap.KOI8R.NewDecoder())
case 16:
reader = transform.NewReader(bytes.NewReader(s), charmap.KOI8U.NewDecoder())
case 17:
reader = transform.NewReader(bytes.NewReader(s), charmap.Macintosh.NewDecoder())
case 18:
reader = transform.NewReader(bytes.NewReader(s), charmap.MacintoshCyrillic.NewDecoder())
case 19:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows874.NewDecoder())
case 20:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1250.NewDecoder())
case 21:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1251.NewDecoder())
case 22:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1252.NewDecoder())
case 23:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1253.NewDecoder())
case 24:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1254.NewDecoder())
case 25:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1255.NewDecoder())
case 26:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1256.NewDecoder())
case 27:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1257.NewDecoder())
case 28:
reader = transform.NewReader(bytes.NewReader(s), charmap.Windows1258.NewDecoder())
case 29:
reader = transform.NewReader(bytes.NewReader(s), charmap.XUserDefined.NewDecoder())
case 30:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage037.NewDecoder())
case 31:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage437.NewDecoder())
case 32:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage850.NewDecoder())
case 33:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage852.NewDecoder())
case 34:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage855.NewDecoder())
case 35:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage858.NewDecoder())
case 36:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage860.NewDecoder())
case 37:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage862.NewDecoder())
case 38:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage863.NewDecoder())
case 39:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage865.NewDecoder())
case 40:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage865.NewDecoder())
case 41:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage866.NewDecoder())
case 42:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage1047.NewDecoder())
case 43:
reader = transform.NewReader(bytes.NewReader(s), charmap.CodePage1140.NewDecoder())
case 44:
reader = transform.NewReader(bytes.NewReader(s), simplifiedchinese.GBK.NewEncoder())
case 45:
reader = transform.NewReader(bytes.NewReader(s), simplifiedchinese.HZGB2312.NewEncoder())
case 46:
reader = transform.NewReader(bytes.NewReader(s), simplifiedchinese.GB18030.NewEncoder())
}

d, _ := ioutil.ReadAll(reader)

return d
}