Android电子邮件发送失败，错误发送失败：发送消息时发生IOException

Question

我有一个邮件发送应用程序，它发送电子邮件和附件。除了附件之外，每一件工作都很好。我正在使用此code。但我不知道这段代码中缺少什么或出了什么问题。请帮忙。这是附件部分。

    public void addAttachment(String filename) throws Exception {
    BodyPart messageBodyPart = new MimeBodyPart();
    DataSource source = new FileDataSource(filename);
    messageBodyPart.setDataHandler(new DataHandler(source));
    messageBodyPart.setFileName(filename);
    multipart.addBodyPart(messageBodyPart);
}

在我的主要活动中，我正在使用

public final static String APP_PATH_SD_CARD = "/Images_Book/";
String path = Environment.getExternalStorageDirectory().getAbsolutePath() + APP_PATH_SD_CARD;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    String mailBody = "Email is send along with attachment";
    Mail m = new Mail("FTP backup failed", mailBody);
    try {
        m.addAttachment(path);
        m.send();
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

Answer 1

尝试

 public final static String APP_PATH_SD_CARD = "/Images_Book/filetobeattached.ext";

而不是

public final static String APP_PATH_SD_CARD = "/Images_Book/";

Answer 2

如下更新功能

public void addAttachment(File filename) throws Exception {
BodyPart messageBodyPart = new MimeBodyPart();
DataSource source = new FileDataSource(filename);
messageBodyPart.setDataHandler(new DataHandler(source));
messageBodyPart.setFileName(filename.getName());
multipart.addBodyPart(messageBodyPart);

}