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()  }