Dart Gmail API“发送”方法返回DetailsApiRequestError

编程问答 2022-08-16

问题描述

我正在重建my personal website in Flutter，需要在填写表格后发送电子邮件

内容：我正在尝试使用Gmail API Dart库发送电子邮件

错误：DetailedApiRequestError（状态：400，消息：“ message.raw”处的值无效（TYPE_BYTES），调用“发送”时Base64解码失败

身份验证正常。我按照googleapis程序包中的步骤使用服务帐户和'clientViaServiceAccount'方法来实现身份验证。

我遵循了Gmail API documentation for sending an email using the send method，创建了MimeMessage，将其格式化为RFC 2822并将其编码为base64url，创建了Message对象，并将'raw'属性设置为已编码的MimeMessage，然后将GmailAPI称为'send'方法。

问题似乎与MimeMessage的编码有关。

我使用enough_mail package创建了MimeMessage并将消息设置为Base 64编码

以下是Github上该项目的链接：https://github.com/ashtonjonesdev/ashton_jones_dev_website “发送”方法位于consulting.dart

中

感谢您的帮助！如果您可以帮助我解决此问题，请在我的文章中大声疾呼

发送电子邮件代码：

sendEmail()  async {

   print('sendEmail');

// Create a Mime Message and encode it using base64

MessageBuilder messageBuilder = MessageBuilder();

messageBuilder.from = [
  MailAddress('Ashton Jones','[email protected]')
];

messageBuilder.to = [MailAddress('Ashton Jones','ashtonjones[email protected]')];

messageBuilder.subject = 'cool subject';

messageBuilder.text = 'cool text';

messageBuilder.encoding = MessageEncoding.base64;

// Added Rfc822 encoding
messageBuilder.contentType = ContentTypeHeader.from(MediaType.fromSubtype(MediaSubtype.messageRfc822));

messageBuilder.messageId = '1';

MimeMessage mimeMessage = messageBuilder.buildMimeMessage();


// Ensure body is also encoded as base64 and Rfc822
mimeMessage.body = BodyPart();
mimeMessage.body.contentType = ContentTypeHeader.from(MediaType.fromSubtype(MediaSubtype.messageRfc822));
mimeMessage.body.encoding = 'base64';

// Create a Message object and set the 'raw' property to the encoded String
Message message = Message();

// Todo Need to set the 'raw' property as the entire encoded MimeMessage
// Todo: figure out if I need to encode the entire MimeMessage as a base 64 String here again (I already set the encoding of the MimeMessage to base64 on line 156)


// Should return the entire encoded MimeMessage
String encodedMimeMessage = mimeMessage.renderMessage();

// Error happening here
message.raw = encodedMimeMessage;

print('Encoded message: ${message.raw}');

// Send the email using the Gmail API 'send' method
// Todo: When I run this,I get an 'invalid value at 'message.raw' (TYPE_BYTES),Base64 decoding Failed' error
Message messageCompleted =
    await _gmailApi.users.messages.send(message,'me').catchError((error) {
  print(error);
});

print(messageCompleted);

}

initState代码：

  @override
   void initState() {
   super.initState();

      print(
      'CREDENTIALS: Client ID: ${_credentials.clientId.toString()} | Client Secret: ${_credentials.privateKey}');

// Authenticate the credentials with the service account and use them to initialize the GmailAPI
clientViaServiceAccount(_credentials,scopes).then((AuthClient httpClient) {
  _gmailApi = GmailApi(httpClient);

  print('Users: ${_gmailApi.users}');
});

}

解决方法

我认为您可能必须像这样对mimeMessage进行编码，

    message.raw = base64.encode(utf8.encode(mimeMessage.renderMessage()));
,

我实现了使用“ mailto”和“ url_launcher” Flutter软件包使用“ mailto”方法发送电子邮件的方法。它必须打开客户端的电子邮件应用程序，但效果很好。用于Dart的Gmail API很糟糕，并且没有文档，所以我建议您采取另一种方法。

  // Send email using mail_to and url_launcher packages

sendEmail（）异步{

print('sendEmail');

final mailtoLink = Mailto(
  to: ['[email protected]'],subject: '$_subject',body: '$_message',);
// Convert the Mailto instance into a string.
// Use either Dart's string interpolation
// or the toString() method.
await launch('$mailtoLink');

}

dartgmail-api