Flutter - 使用 Google API 发送电子邮件

Question

经过大量研究和修复问题，我到达了我的github中的以下位置。但我不知道我是否正确安装了 json。对于出现以下错误：

{
  error: 
    {
      errors: [
        {
          domain: global,
          reason: parseError,
          message: This API does not support parsing form-encoded input.
        }
      ],
      code: 400,
      message: This API does not support parsing form-encoded input.
    }
}

我正在设置帖子如下，更多细节项目在我的github中

// scope for send email
GoogleSignIn googleSignIn = new GoogleSignIn(
  scopes: <String>[
    'https://www.googleapis.com/auth/gmail.send'
  ],
);

await googleSignIn.signIn().then((data) {                          
  testingEmail(data.email, data.authHeaders);                          
});


// userId is the email
Future<Null> testingEmail(userId, header) async {
  String url = 'https://www.googleapis.com/gmail/v1/users/' + userId + '/messages/send';
  final http.Response response = await http.post(
    url,
    headers: await header,
    body: {
      'from': userId,
      'to': userId,
      'subject': 'testing send email',
      'text': 'worked!!!'
    }
  );
}

我做错了什么，无法通过 Google API 发送电子邮件？你能帮我解决这个问题吗？

Answer 1

做了一些改动，主要是http post body需要是一个json，rawkey和内容在里面，base64而且这个转base64的文本必须是MIMEText，所以具体格式如下。

要将 html 更改为文本，只需Content-Type: text/html将字符串从字符串更改为Content-Type: text/plain

以下是代码的剪辑。完整代码在github

await googleSignIn.signIn().then((data) {
  data.authHeaders.then((result) {
    var header = {'Authorization': result['Authorization'], 'X-Goog-AuthUser': result['X-Goog-AuthUser']};
    testingEmail(data.email, header);
  });                          
});

Future<Null> testingEmail(String userId, Map header) async {
  header['Accept'] = 'application/json';
  header['Content-type'] = 'application/json';

  var from = userId;
  var to = userId;
  var subject = 'test send email';
  //var message = 'worked!!!';
  var message = "Hi<br/>Html Email";
  var content = '''
Content-Type: text/html; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
to: ${to}
from: ${from}
subject: ${subject}

${message}''';

  var bytes = utf8.encode(content);
  var base64 = base64Encode(bytes);
  var body = json.encode({'raw': base64});

  String url = 'https://www.googleapis.com/gmail/v1/users/' + userId + '/messages/send';

  final http.Response response = await http.post(
    url,
    headers: header,
    body: body
  );
  if (response.statusCode != 200) {
    setState(() {
      print('error: ' + response.statusCode.toString());
    });
    return;
  }
  final Map<String, dynamic> data = json.decode(response.body);
  print('ok: ' + response.statusCode.toString());
}