golang 将读取二进制文件到struct的方法

代码如下：

package main

import (
    "bytes"
    "encoding/binary"
    "fmt"
    "log"
    "math/rand"
    "os"
    "time"
)

//this type represnts a record with three fields
type payload struct {
    One   float32
    Two   float64
    Three uint32
}

func main() {
    writeFile()
    readFile()

}

func readFile() {
    file, err := os.Open("test.bin")
    defer file.Close()
    if err != nil {
        log.Fatal(err)
    }

    m := payload{}
    for i := 0; i < 10; i++ {
        data := readNextBytes(file, 16)
        buffer := bytes.NewBuffer(data)
        err = binary.Read(buffer, binary.BigEndian, &m)
        if err != nil {
            log.Fatal("binary.Read failed", err)
        }

        fmt.Println(m)
    }
}

func readNextBytes(file *os.File, number int) []byte {
    bytes := make([]byte, number)

    _, err := file.Read(bytes)
    if err != nil {
        log.Fatal(err)
    }

    return bytes
}

func writeFile() {
    file, err := os.Create("test.bin")
    defer file.Close()
    if err != nil {
        log.Fatal(err)
    }

    r := rand.New(rand.NewSource(time.Now().UnixNano()))
    for i := 0; i < 10; i++ {
        s := &payload{
            r.Float32(),
            r.Float64(),
            r.Uint32(),
        }
        var bin_buf bytes.Buffer
        binary.Write(&bin_buf, binary.BigEndian, s)
        //b :=bin_buf.Bytes()
        //l := len(b)
        //fmt.Println(l)
        writeNextBytes(file, bin_buf.Bytes())
    }
}

func writeNextBytes(file *os.File, bytes []byte) {
    _, err := file.Write(bytes)

    if err != nil {
        log.Fatal(err)
    }
}

 

除了将数据放进结构体之外，你还可以直接将数据放进结构体对象的某个成员里:

binary.Read(buffer, binary.BigEndian, &m.Two)

不过要保证buffer与成员的内存长度一样。