我正在嘗試向我的郵件發(fā)件人添加一個(gè)附件按鈕。我正在使用 JavaMail Mail、activation 和 additionalnal 庫(kù)。我的發(fā)件人被分成 3 個(gè)文件：允許用戶設(shè)置郵件內(nèi)容的MainActivity編輯文本SendMail允許我設(shè)置發(fā)件人，以及從編輯文本到郵件的內(nèi)容并發(fā)送存儲(chǔ)發(fā)送者地址和密碼以及接收者地址等信息的配置這是我的實(shí)際郵件發(fā)件人的代碼，它可以正確發(fā)送郵件但沒有附件。發(fā)送郵件.javapackage com.myapp.attch_mail;import android.annotation.SuppressLint;import android.app.ProgressDialog;import android.content.Context;import android.os.AsyncTask;import android.widget.Toast;import java.util.Properties;import javax.mail.Message;import javax.mail.MessagingException;import javax.mail.PasswordAuthentication;import javax.mail.Session;import javax.mail.Transport;import javax.mail.internet.InternetAddress;import javax.mail.internet.MimeMessage;public class SendMail extends AsyncTask<Void,Void,Void> {private Context context;private String subject;private String message;private ProgressDialog progressDialog;SendMail(Context context, String subject, String message){    this.context = context;    this.subject = subject;    this.message = message;}@Overrideprotected void onPreExecute() {    super.onPreExecute();    progressDialog = ProgressDialog.show(context,"Envoi en cours","Veuillez patienter...",false,false);}@Overrideprotected void onPostExecute(Void aVoid) {    super.onPostExecute(aVoid);    progressDialog.dismiss();    Toast.makeText(context,"Message sent",Toast.LENGTH_LONG).show();}@Overrideprotected Void doInBackground(Void... params) {    Properties props = new Properties();    props.put("mail.smtp.host", "smtp.gmail.com");    props.put("mail.smtp.socketFactory.port", "465");    props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");    props.put("mail.smtp.auth", "true");    props.put("mail.smtp.port", "465");    Session session = Session.getDefaultInstance(props,            new javax.mail.Authenticator() {                protected PasswordAuthentication getPasswordAuthentication() {                    return new PasswordAuthentication(Config.EMAIL_SENDER, Config.PASSWORD);                }            });