不能发布多个文件

Question

我知道如何上传单个文件，但现在我正尝试在同一个 Go 函数中上传多个文件。这是我的代码：func PhotoCreatePOST(w http.ResponseWriter, r  *http.Request) {    var err errorr.ParseMultipartForm(32 << 20) // 32MB is the default used by FormFilefhs := r.MultipartForm.File["files"]var fileNames []stringvar filename stringvar ext stringfor _, file := range fhs { //Iterate over multiple uploaded files    if err != nil {        log.Fatal(err)    } else {        dir, err := os.Getwd()        if err != nil {            log.Fatal(err)        }        ext = strings.ToLower(path.Ext(file.Filename))        filename = path.Join(random.RandString(10) + ext)        destFolder := "/media/photos"        if _, err := os.Stat(destFolder); os.IsNotExist(err) {            os.Mkdir(destFolder, 0755)        }        //destination Path. The string which is Saving in DB        savePath := destFolder + "/" + filename        err = ioutil.WriteFile(savePath, file, 0777) //<--Here is the problem        if err != nil {            log.Println(err)            io.WriteString(w, err.Error())            return        }    }}//Add file url to the slicefileNames = append(fileNames, filename)}但我收到此错误：cannot use file (type *multipart.FileHeader) as type []byte in argument to ioutil.WriteFile我试过file像这样读入字节：b, err := ioutil.ReadFile(file)     if err != nil {        fmt.Print(err)    }并保存b而不是file.但后来我得到另一个错误can not read *multipart.Fileheader as string 我怎样才能解决这个问题？

Answer 1

这里是记录的完整解决方案：

// PhotoCreatePOST saves multiple photo uploads

func PhotoCreatePOST(w http.ResponseWriter, r *http.Request) {

    err := r.ParseMultipartForm(100000)

    if err != nil {

        fmt.Println("error parsing multiplepart form", err)

        return

    }

    files := r.MultipartForm.File["files"]

    for i, _ := range files { //Iterate over multiple uploaded files

        file, err := files[i].Open()

        defer file.Close()

        if err != nil {

            fmt.Println("error opening file ", err)

            return

        }

        ext := path.Ext(files[i].Filename)

        //TODO: Verify extension is valid

        filename := GetRandomString(10) + ext

        //create destination file making sure the path is writeable.

        dst, err := os.Create("media/photos/" + filename)

        defer dst.Close()

        if err != nil {

            fmt.Println("error creating destination ", err)

            return

        }

        //copy the uploaded file to the destination file

        if _, err := io.Copy(dst, file); err != nil {

            fmt.Println("error copying file", err)

            return

        }

        fmt.Println("Image upload success: ", files[i].Filename)

    }

    fmt.Println("all are uploaded")

    PhotoCreateGET(w, r)

    return 

}

//Generate random filename (never trust user input!)

var letterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789")

// GetString returns a random string

func GetRandomString(n int) string {

    rand.Seed(time.Now().UnixNano())

    b := make([]rune, n)

    for i := range b {

        b[i] = letterRunes[rand.Intn(len(letterRunes))]

    }

    return string(b)

}

以及上传表格：

<form method="post" action="/create/photo" enctype="multipart/form-data">

        <input type="file"  name="files"  multiple>

        <input type="hidden" name="token" value="{{.token}}">

        <button title="submit" type="submit" >Save </button>

</form>

瞧。希望它可以为其他人节省一些时间。

Answer 2

这大致就是您的操作方式。

fileHeaders := r.MultipartForm.File["files"]

var fileNames []string

for _, fileHeader := range fileHeaders {

    file, err := fileHeader.Open()

    if err != nil {

        return err

    }

    defer file.Close()

    // Generate the destination filename randomly. Using even the passed

    // extension is a security vulnerability unless you have a whitelist.

    dest, err := ioutil.TempFile("/media/photos", "")

    if err != nil {

        return err

    }

    defer dest.Close()

    if _, err := io.Copy(dest, file); err != nil {

        return err

    }

    fileNames = append(fileNames, dest.Name())

}