package main      import (     "os"     "encoding/csv" )      func main() {     f, err := os.Create("haha2.xls")     if err != nil {         panic(err)     }     defer f.Close()          f.WriteString("\xEF\xBB\xBF") // 写入UTF-8 BOM          w := csv.NewWriter(f)     w.Write([]string{"编号","姓名","年龄"})     w.Write([]string{"1","张三","23"})     w.Write([]string{"2","李四","24"})     w.Write([]string{"3","王五","25"})     w.Write([]string{"4","赵六","26"})     w.Flush() }