如何在Go中将[]byte转换为io.Reader

package main

import (
 "bytes"
 "fmt"
 "log"
)

func main() {
 data := []byte("Hello AlwaysBeta")

 // byte slice to bytes.Reader, which implements the io.Reader interface
 reader := bytes.NewReader(data)

 // read the data from reader
 buf := make([]byte, len(data))
 if _, err := reader.Read(buf); err != nil {
  log.Fatal(err)
 }

 fmt.Println(string(buf))
}

package main

import (
 "bytes"
 "fmt"
 "strings"
)

func main() {
 ioReaderData := strings.NewReader("Hello AlwaysBeta")

 // creates a bytes.Buffer and read from io.Reader
 buf := &bytes.Buffer{}
 buf.ReadFrom(ioReaderData)

 // retrieve a byte slice from bytes.Buffer
 data := buf.Bytes()

 // only read the left bytes from 6
 fmt.Println(string(data[6:]))
}

type Reader interface {
    Read(p []byte) (n int, err error)
}

package main

import (
 "fmt"
 "io"
 "os"
 "strings"
)

func main() {
 reader := strings.NewReader("Clear is better than clever")
 p := make([]byte, 4)

 for {
  n, err := reader.Read(p)
  if err != nil {
   if err == io.EOF {
    fmt.Println("EOF:", n)
    break
   }
   fmt.Println(err)
   os.Exit(1)
  }
  fmt.Println(n, string(p[:n]))
 }
}

type Writer interface {
   Write(p []byte) (n int, err error)
}

package main

import (
 "bytes"
 "fmt"
 "os"
)

func main() {
 // 创建 Buffer 暂存空间，并将一个字符串写入 Buffer
 // 使用 io.Writer 的 Write 方法写入
 var buf bytes.Buffer
 buf.Write([]byte("hello world , "))

 // 用 Fprintf 将一个字符串拼接到 Buffer 里
 fmt.Fprintf(&buf, " welcome to golang !")

 // 将 Buffer 的内容输出到标准输出设备
 buf.WriteTo(os.Stdout)
}

func (b *Buffer) WriteTo(w io.Writer) (n int64, err error)

// src/bytes/reader.go

// NewReader returns a new Reader reading from b.
func NewReader(b []byte) *Reader { return &Reader{b, 0, -1} }

// src/strings/reader.go

// NewReader returns a new Reader reading from s.
// It is similar to bytes.NewBufferString but more efficient and read-only.
func NewReader(s string) *Reader { return &Reader{s, 0, -1} }