当设备的方向改变时，带有 fragment 的 android Activity 退出

Question

我的应用包含一个 Activity ，该 Activity 由两个 fragment 组成。第一个 fragment 是通过 XML 添加的，第二个 fragment 是根据第一个 fragment 的输入动态添加的。该应用程序在模拟器上完美运行。但是，当在真实设备(三星 galaxy 选项卡)上进行测试时，应用程序会在更改设备方向时简单地退出(不会崩溃，也不会出现任何错误)。我正在使用安卓 4.0.我搜索了很多这个问题并尝试了本网站和其他网站提供的各种解决方案，但问题仍然存在。我还想补充一点，我的应用程序不使用 fragment 的版本在两个方向上都可以正常工作。

主布局文件(activity_main.xml)

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" 
android:orientation="vertical" >

<fragment 
android:name="androiapps.autoqos.FirstFragment"
android:id="@+id/fragment"
android:layout_weight="2"
android:layout_width="fill_parent"
android:layout_height="0dp" 
/>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_weight="1"
android:layout_height="0dp"
android:orientation="vertical"
android:id="@+id/frameLayout" >

</FrameLayout>
</LinearLayout>

MainActivity.java

public class MainActivity extends FragmentActivity implements OnInputReceivedListener, MessageSendListener{
//variable declarations 

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

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

@Override
public void onConfirm(Bundle bundle) {
    // TODO Auto-generated method stub
    if(bundle!=null){
        //int PT = bundle.getInt("PT");
        System.out.println("Got:"+bundle.getString("ip")+bundle.getString("port")+bundle.getString("tcpip")
                +bundle.getString("tcpport")+bundle.getInt("PT",0));
        udpHost=bundle.getString("ip");
        udpPort=bundle.getString("port");
        tcpHost=bundle.getString("tcpip");
        tcpPort=bundle.getString("tcpport");
        pType=bundle.getInt("pType",0);
        FragmentManager fragmentManager = getSupportFragmentManager();
        MessageFragment fragment = new MessageFragment();
        fragment.setArguments(bundle);
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.frameLayout, fragment);
        transaction.commit();
    }
}

@Override
public void send(Bundle bundle) {
    // TODO Auto-generated method stub
    if(bundle==null)
        return;

    msg = bundle.getString("msg");
    delay = bundle.getInt("delay",0);
    System.out.println("Got: "+msg+delay);          
    startTransmission();
}
void startTransmission(){
    System.out.println("\nTrying to send data");
    sendFilter = new IntentFilter(UdpResponseReceiver.ACTION_RESP1);
    sendFilter.addCategory(Intent.CATEGORY_DEFAULT);
    receiver1 = new UdpResponseReceiver(); 
    receiveFilter = new IntentFilter(UdpHandlerReceiver.ACTION_RESP2);
    receiveFilter.addCategory(Intent.CATEGORY_DEFAULT);
    receiver2 = new UdpHandlerReceiver();
    registerReceiver(receiver1, sendFilter);
    registerReceiver(receiver2, receiveFilter);
    udpServiceIntent = new Intent(MainActivity.this,UdpSendService.class);
    udpReceiveIntent = new Intent(MainActivity.this,UdpReceiveService.class);
    udpServiceIntent.putExtra("host",udpHost);
    udpServiceIntent.putExtra("port", udpPort);
    udpServiceIntent.putExtra("msg",msg);
    udpServiceIntent.putExtra("delay",delay);
    udpServiceIntent.putExtra("pType",pType);
    startService(udpServiceIntent);
    udpReceiveIntent.putExtra("tcpHost", tcpHost);
    udpReceiveIntent.putExtra("tcpPort", tcpPort);
    startService(udpReceiveIntent);
}
public class UdpResponseReceiver extends BroadcastReceiver {
    public static final String ACTION_RESP1 = "com.example.udpmessageclient.intent.action.MESSAGE_PROCESSED";
    @Override
    public void onReceive(Context context, Intent intent) {

        // Update UI, new "message" processed by SimpleIntentService
        System.out.println(intent.getStringExtra(UdpSendService.PARAM_OUT_MSG));

    }      
}   
public class UdpHandlerReceiver extends BroadcastReceiver {
    public static final String ACTION_RESP2 = "com.example.udpmessageclient.intent.action.MESSAGE_RECEIVED";
    @Override
    public void onReceive(Context context, Intent intent) {

        // Update UI, new "message" processed by SimpleIntentService
        System.out.println("Received message from server: "+intent.getStringExtra(UdpReceiveService.OUT_MSG));

    }    
}

@Override
public void stop() {
    // TODO Auto-generated method stub
    endTransmission();
    Button btn = (Button)findViewById(R.id.btn_confirm);
    btn.setEnabled(true);

}
void endTransmission(){
    UdpSendService.send=false;
    if(receiver1!=null && receiver2!=null){
        unregisterReceiver(receiver1);
        unregisterReceiver(receiver2);
        receiver1=null;
        receiver2=null;
    }
    //while(stopService(udpReceiveIntent)!=true);
    if(udpReceiveIntent!=null)
        stopService(udpReceiveIntent);
    System.out.println("\nreceive service stopped");
    //while(stopService(udpServiceIntent)!=true);
    if(udpServiceIntent!=null)
        stopService(udpServiceIntent);
    System.out.println("\nsend service stopped");
    return;
}
@Override
public void onBackPressed() {
    if(UdpSendService.send)
        stop();
    finish();

}
@Override
public void onStop() {
    super.onStop();
    stop();
    finish();
}

    }

FirstFragment.java

public class FirstFragment extends Fragment{
//variable declarations
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View contentView = inflater.inflate(R.layout.activity_message_form, null);
    contentView.setDrawingCacheEnabled(false);
    text1 = (EditText) contentView.findViewById(R.id.ip);
    text2 = (EditText) contentView.findViewById(R.id.port);
    text3 = (EditText) contentView.findViewById(R.id.tcpip);
    text4 = (EditText) contentView.findViewById(R.id.tcpport);
    if(onSaveInstance!=null){
        text1.setText(onSaveInstance.getString("ip"));
        text2.setText(onSaveInstance.getString("port"));
        text3.setText(onSaveInstance.getString("tcpip"));
        text4.setText(onSaveInstance.getString("tcpport"));
    }
    button= (Button) contentView.findViewById(R.id.btn_confirm);
    rb1 = (RadioButton) contentView.findViewById(R.id.rbtn_1);
    rb2 = (RadioButton) contentView.findViewById(R.id.rbtn_2);
    rb3 = (RadioButton) contentView.findViewById(R.id.rbtn_3);
    rb4 = (RadioButton) contentView.findViewById(R.id.rbtn_4);
    confirmButtonListener = new OnClickListener(){
        public void onClick(View view){
            button.setEnabled(false);
            if (rb1.isChecked())
                PT = 0;
            else if (rb2.isChecked())
                PT = 1;
            else if (rb3.isChecked())
                PT = 2;
            else if (rb4.isChecked())
                PT = 3;
            else
                PT = 0;
            ip = text1.getText().toString().trim();
            port = text2.getText().toString().trim();
            tcpip=text3.getText().toString().trim();
            tcpport=text4.getText().toString().trim();
            if(ip=="" || port=="" || tcpip == "" || tcpport ==""){
                Toast.makeText(getActivity(), "Please fill in all the fields", Toast.LENGTH_SHORT).show();
            }
            else{
                Bundle b = new Bundle();
                b.putString("ip",ip);
                b.putString("port", port);
                b.putString("tcpip",tcpip);
                b.putString("tcpport", tcpport);
                b.putInt("pType", PT);

                if ( listener != null ){
                    System.out.println("Bundle:"+ip+port+tcpip+tcpport+PT);
                    listener.onConfirm(b);
                }
            }
            }
    };
    return contentView;
}
@Override
public void onStart(){
super.onStart();
button.setOnClickListener(confirmButtonListener);
}
@Override
public void onAttach(Activity activity) {
// TODO Auto-generated method stub
super.onAttach(activity);
try {
    listener = (OnInputReceivedListener)activity;
}catch (ClassCastException e) {
    Toast.makeText( activity, "Activity must implement this interface.", Toast.LENGTH_SHORT).show();
}
}
public interface OnInputReceivedListener{
    public void onConfirm(Bundle bundle);
}
@Override
public void onPause(){
    super.onPause();
    onSaveInstance = new Bundle();
    onSaveInstance.putString("udpHost", ip);
    onSaveInstance.putString("udpPort", port);
    onSaveInstance.putString("tcpHost", tcpip);
    onSaveInstance.putString("tcpPort", tcpport);

}
@Override
public void onResume(){
    super.onResume();
    if(onSaveInstance!=null){
        text1.setText(onSaveInstance.getString("ip"));
        text2.setText(onSaveInstance.getString("port"));
        text3.setText(onSaveInstance.getString("tcpip"));
        text4.setText(onSaveInstance.getString("tcpport"));
    }
}
}

MessageFragment.java

public class MessageFragment extends Fragment{
//variable declarations
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View contentView = inflater.inflate(R.layout.activity_message, null);
    contentView.setDrawingCacheEnabled(false);
    msgText = (EditText) contentView.findViewById(R.id.msg);
    sendBtn = (Button) contentView.findViewById(R.id.btn_send);
    stopBtn = (Button) contentView.findViewById(R.id.btn_stop);
    if(onSaveInstance!=null){
        msgText.setText(onSaveInstance.getString("msg"));
        delayField.setText(onSaveInstance.getInt("delay", 0));
    }
    b = getArguments();
    System.out.println("PT="+b.getInt("pType",0));
    if(b!=null){
        int pType = b.getInt("pType");
        if(pType==1 || pType== 3){
            delayField = (EditText) contentView.findViewById(R.id.delay);
            tvDelay = (TextView) contentView.findViewById(R.id.tvDelay);
            tvDelay.setVisibility(View.VISIBLE);
            delayField.setVisibility(View.VISIBLE);
        }
    }
    sendButtonListener=new OnClickListener(){

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            sendBtn.setEnabled(false);
            Bundle b = new Bundle();
            msg=msgText.getText().toString();
            delay=Integer.parseInt(delayField.getText().toString());
            b.putString("msg", msg);
            if(delayField!=null)
                b.putInt("delay",delay);
            if(mListener!=null)
                mListener.send(b);
        }
    };
    stopButtonListener = new OnClickListener(){

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            sendBtn.setEnabled(true);
            mListener.stop();
        }
    };
    return contentView;
}
@Override
public void onStart(){
    super.onStart();
    sendBtn.setOnClickListener(sendButtonListener);
    stopBtn.setOnClickListener(stopButtonListener);
}
@Override
public void onAttach(Activity activity) {
    // TODO Auto-generated method stub
    super.onAttach(activity);
    try {
        mListener = (MessageSendListener)activity;
    }catch (ClassCastException e) {
        Toast.makeText( activity, "Activity must implement this interface.", Toast.LENGTH_SHORT).show();
    }
}
public interface MessageSendListener{
    public void send(Bundle bundle);
    public void stop();
}
@Override
public void onPause(){
    super.onPause();
    onSaveInstance = new Bundle();
    onSaveInstance.putString("msg", msg);
    onSaveInstance.putInt("delay", delay);
}
@Override
public void onResume(){
    super.onResume();
    if(onSaveInstance!=null){
        msgText.setText(onSaveInstance.getString("msg"));
        delayField.setText(onSaveInstance.getInt("delay", 0));
    }
}
}

Answer 1

public void onStop() {
    super.onStop();
    stop();
    finish();

为什么要完成()？您的应用程序完全按照您编写的代码执行。当方向改变时，调用 onStop()。然后你finish()你的 Activity 。