BroadcastReceiver onReceive方法中的异步任务没有运行?

时间:2018-03-27 16:23:58

标签: java android broadcastreceiver android-broadcastreceiver

我有一个工作应用程序,它将应用程序输入文本字段中的字符串数据发送到我PC上的TCP服务器。 我已经添加了BroadcastReceiver类,以便在收到消息时将消息发送到计算机。 应用程序接收消息(Toast正在工作),但我无法将收到的消息发送到PC。

没有错误。应用程序只是跳过名为。

的方法

如何在onReceive中调用方法?

感谢您的帮助!

public class SmsReceiver extends BroadcastReceiver {
String phone;
String message;

@Override
public void onReceive(Context context, Intent intent) {
    Bundle intentExtras = intent.getExtras();

    if (intentExtras != null) {
        // Get Messages
        Object[] sms = (Object[]) intentExtras.get("pdus");

        for (int i = 0; i < sms.length; ++i) {
            // Parse Each Message
            SmsMessage smsMessage = SmsMessage.createFromPdu((byte[]) sms[i]);

            phone = smsMessage.getOriginatingAddress();
            message = smsMessage.getMessageBody().toString();
            System.out.println("Message is: "+message);
            Log.i("sth","message "+message);

            //What i have tried
            sendMessage(message);

            //creating instance
            MessageSender messageSender = new MessageSender();
            messageSender.execute(message);

            //calling metod from MainActivity
            ((MainActivity)context.getApplicationContext()).send2(message);

            MainActivity.send2(message);

            //toast is working fine
            Toast.makeText(context,"Alert:"+ phone + ": " + message, Toast.LENGTH_SHORT).show();
        }
    }
}
public void sendMessage(String s)
{
    MessageSender messageSender = new MessageSender();
    messageSender.execute(s);
}

MainActivity

public class MainActivity extends AppCompatActivity {

EditText e1;

@Override
protected void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    e1 = (EditText)findViewById(R.id.editText);
    //This works
    MessageSender messageSender = new MessageSender();
    messageSender.execute("App launched!");
}

//On Button click. Working good.
public void send(View v)
{
    MessageSender messageSender = new MessageSender();
    messageSender.execute(e1.getText().toString());
}
//For test purposes
public static void send2(String s)
{
    MessageSender messageSender = new MessageSender();
    messageSender.execute(s);
}

messageSender,和

public class MessageSender extends AsyncTask<String,Void,Void>
{
Socket s;
DataOutputStream dos;
PrintWriter pw;

@Override
public Void doInBackground(String... voids) {

    String message = voids[0];
try {
    s = new Socket("192.168.1.69", 7800);
    pw = new PrintWriter(s.getOutputStream());
    pw.write(message);
    pw.flush();
    pw.close();
    s.close();

}catch(IOException e)
{
    e.printStackTrace();
}
    return null;
}

}

添加了服务器代码:

  public class MyServerFrame extends javax.swing.JFrame 
  {
  static Socket s;
   static ServerSocket ss;
  static InputStreamReader isr;
  static BufferedReader br;
  static String message;public MyServerFrame() 
 {

}

public static void main(String args[]) 
{   
    try 
    {
        ss = new ServerSocket(7800);
        while(true)
        {
            s=ss.accept();
            isr = new InputStreamReader(s.getInputStream());
            br = new BufferedReader(isr);
            StringBuilder everything = new StringBuilder();
            String line;
            while( (line = reader.readLine()) != null) 
            {
               everything.append(line);
            }
            message = everything.toString();//multiple to onelinestring 
            System.out.println(message);
        }   
    }catch (IOException e) 
    {
        e.printStackTrace();
    }
}

}

2 个答案:

答案 0 :(得分:0)

问题在于,由于您在onReceive方法中使用异步任务执行网络请求,因此在AsyncTask执行之前,onReceive方法会返回,因为异步任务是异步的。因此,运行onRequest方法的进程变为低优先级,因为onReceive方法已返回,并且操作系统将在异步任务实际执行之前将其终止。

以下是两个解决方案:

首先确保在Android清单中声明接收器,然后执行以下操作之一。

  1. 不是调用异步任务来执行网络请求,而是创建服务并使用该服务运行网络代码。

  2. 您可以在onReceive方法中调用goAsync()方法,告诉系统给接收者更多时间来执行其异步任务。这个代码就像这样:

    @Override
    public void onReceive(final Context context, final Intent intent) {
    //create a pending intend that you will pass to the Async task so you can tell the system when the Async Task finished so that it can recycle.
    final PendingResult pendingResult = goAsync();
     AsyncTask<String, Integer, String> asyncTask = new AsyncTask<String,  Integer, String>() {
        @Override
        protected String doInBackground(String... params) {
            //put the network calling code in here
    
            // Must call finish() so the BroadcastReceiver can be recycled.
            pendingResult.finish();
            return data;
        }
    };
    asyncTask.execute();
     }
    
  3. 我认为第二种方式会更简单,所以我建议使用它,因为它不需要你创建一个全新的服务。

答案 1 :(得分:0)

感谢SteelToe带领我这个简单的解决方案:

  

未在清单文件中声明接收方。