golang采集中文gbk编码的内容转成utf8中文编码乱码了

func GetContent(url string) ( map[string]string) {
captures:=make(map[string]string)
//fmt.Println(url)
res,err := http.Get(url)
if err !=nil {
fmt.Println("获取远程内容为空")
fmt.Println(err)
return captures
}
body,err := ioutil.ReadAll(res.Body)
if err !=nil {
fmt.Println("解析错误")
return captures
}
html := string(body)
enc := mahonia.NewEncoder("UTF-8")
strr := enc.ConvertString(html)
fmt.Println(strr)
os.Exit(0)
regex,err:= regexp.Compile("<li><a href=\".*\">(.*?)</a>")
urls := regex.FindAllStringSubmatch(enc.ConvertString(html),-1)
fmt.Println(urls)
os.Exit(0)
for i,j := range urls {
captures[strconv.Itoa(i)]=j[1]
}
res.Body.Close()
return captures
}