将图像附加到通过 golang gmail api 发送的电子邮件

Question

我正在尝试将图片附加到通过 gmail golang api 发送的电子邮件中，但该图片未附加。我已经广泛查看了文档，但我无法弄清楚如何将图像附加到电子邮件中。这是我到目前为止的代码。它只发送文本。// SendEmailEmbed2 Sends email through gmailfunc (config *GmailConfig) SendEmailEmbed2(person int, formattedTemplate string) {    msg := formattedTemplate    mmbody := gmail.MessagePartBody{        Data: encodeWeb64String([]byte(msg)),    }    headers := []*gmail.MessagePartHeader{        &gmail.MessagePartHeader{            Name:  "From",            Value: config.FromAddress,        },        &gmail.MessagePartHeader{            Name:  "To",            Value: config.CSVReference.Elem(person, config.PlugIns[0].ToEmail).String(),        },        &gmail.MessagePartHeader{            Name:  "Subject",            Value: config.EmailSubject,        },        &gmail.MessagePartHeader{            Name:  "Content-Disposition",            Value: "./prac2_files/image001.jpg",        },    }    Parts := []*gmail.MessagePart{        &gmail.MessagePart{            Filename: "./prac2_files/image001.jpg",        },    }    partgmsg := gmail.MessagePart{        Body: &mmbody,        Headers: headers,        Parts: Parts,        MimeType: "multipart",    }    im, _ := os.Open("./prac2_files/image001.jpg")    gmsg := gmail.Message{        Payload: &partgmsg,        Raw:     encodeWeb64String([]byte(msg)),    }    call, err := config.srv.Users.Messages.Send("me", &gmsg).Media(im).Do()    im.Close()    if err != nil {        log.Println("em %v, err %v", gmsg, err)        // return err    }    // return err     fmt.Println(person, ":", headers[1].Value, " : ", call.LabelIds)}func encodeWeb64String(b []byte) string {    s := base64.URLEncoding.EncodeToString(b)    var i = len(s) - 1    for s[i] == '=' {        i--    }    return s[0 : i+1]}

Answer 1

回答：

您需要在邮件正文中附加内联文件。

代码：

message := gmail.Message

attachmentBytes := ioutil.ReadFile(fileDir + fileName)

attachmentMimeType: = http.DetectContentType(attachmentBytes)

attachmentData: = base64.StdEncoding.EncodeToString(attachmentBytes)

boundary: = randStr(32, "alphanum")

messageBody: = [] byte("Content-Type: multipart/mixed; boundary=" + boundary + " \n" +

    "MIME-Version: 1.0\n" +

    "to: " + config.CSVReference.Elem(person, config.PlugIns[0].ToEmail).String() + "\n" +

    "from: " + config.FromAddress + "\n" +

    "subject: " + config.EmailSubject + "\n\n" +

    "--" + boundary + "\n" +

    "Content-Type: text/plain; charset=" + string('"') + "UTF-8" + string('"') + "\n" +

    "MIME-Version: 1.0\n" +

    "Content-Transfer-Encoding: 7bit\n\n" +

    content + "\n\n" +

    "--" + boundary + "\n" +

    "Content-Type: " + "image/jpg" + "; name=" + string('"') + fileName + string('"') + " \n" +

    "MIME-Version: 1.0\n" +

    "Content-Transfer-Encoding: base64\n" +

    "Content-Disposition: attachment; filename=" + string('"') + fileName + string('"') + " \n\n" +

    chunkSplit(attachmentData, 76, "\n") +

    "--" + boundary + "--")

message.Raw = base64.URLEncoding.EncodeToString(messageBody)

_, err := service.Users.Messages.Send("me", &message).Do()

if err != nil {

    log.Fatalf("Email sending failed: %v", err)

} else {

    log.Println("Email message sent")

}