android - 从其他 Activity 中错误地调用了 onCreate() 和 onPause()

Question

我的问题是关闭 Activity 中的 onCreate() 和 onPause() 在不应该被调用时被调用。

我调用的开始 Activity :

Intent intent = new Intent(this, SelectTransportActivity.class);
startActivity(intent);
this.finish();

当我想启动 SelectTransport Activity 时。

但是当我想从 SelectTransport Activity 启动停止 Activity 时，我调用

Intent i = new Intent(this, StopActivity.class);
startActivity(i);
this.finish();

我可以在调试器中看到 Start Activity 中的 onCreate() 在 Stop Activity 开始之前被调用。

同样，当我完成 Stop Activity 时，将调用 Start Activity 中的 onPause()，然后 Start Activity 开始。

为什么 onCreate() 和 onPause() 在 Start Activity 中从其他 Activity 中调用，而我已经完成了 Activity ，而它们不应该被调用？

list :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.greenenergy"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="17" />

    <!-- Launching -->
<uses-permission android:name="android.permission.BATTERY_STATS" />
<!-- All probes -->
<uses-permission android:name="android.permission.WAKE_LOCK" />
<!-- Storage -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- Location probe -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" 
    android:name=".GreenEnergyApplication">

    <service android:name="edu.mit.media.funf.FunfManager" >
        <meta-data
            android:name="default"
            android:value="@string/default_pipeline" />
    </service>

    <receiver
        android:name="edu.mit.media.funf.Launcher"
        android:enabled="true" >
        <intent-filter>
            <action android:name="android.intent.action.BATTERY_CHANGED" />
            <action android:name="android.intent.action.BOOT_COMPLETED" />
            <action android:name="android.intent.action.DOCK_EVENT" />
            <action android:name="android.intent.action.ACTION_SCREEN_ON" />
            <action android:name="android.intent.action.USER_PRESENT" />
        </intent-filter>
    </receiver>

    <activity
        android:name="com.example.greenenergy.StartupActivity"
        android:screenOrientation="portrait"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="com.example.greenenergy.StartActivity"
        android:screenOrientation="portrait"
        android:label="@string/title_activity_start" >
    </activity>
    <activity
        android:name="com.example.greenenergy.WaysActivity"
        android:screenOrientation="portrait"
        android:label="@string/title_activity_ways" >
    </activity>
    <activity
        android:name="com.example.greenenergy.StopActivity"
        android:screenOrientation="portrait"
        android:label="@string/title_activity_stop">
    </activity>
    <activity
        android:name="com.example.greenenergy.StatisticsActivity"
        android:screenOrientation="portrait"
        android:label="@string/title_activity_statistics">
    </activity>
</application>

开始 Activity :

public class StartActivity extends BaseActivity implements OnClickListener {
private Button bStart, bStats;
Controller controller;
GPSCollectorSingleton gpsCollectorSingleton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    init();

    autoDetect();
}

private void init() {
    setContentView(R.layout.activity_main);

    bStart = (Button) findViewById(R.id.bStart);
    bStats = (Button) findViewById(R.id.bStatisticsStart);

    bStart.setOnClickListener(this);
    bStats.setOnClickListener(this);

    controller = new Controller(); // Init controller
    Database database = new Database(getApplicationContext());
    controller.controlDatabase(database);
    controller.createTable(); // Create table if not exist

    gpsCollectorSingleton = GPSCollectorSingleton.getInstance(); // Init model

    // Bind to the service, to create the connection with FunfManager
    getApplicationContext().bindService(new Intent(this, FunfManager.class), funfManagerConn, BIND_AUTO_CREATE);
}

private void autoDetect() {
    boolean auto = ((GreenEnergyApplication) getApplication()).getAutoPreference(getApplicationContext());
    boolean started = ((GreenEnergyApplication) getApplication()).getStartPreference(getApplicationContext());

    if (auto && !started) {
        controller.enableAutoDetection(getApplicationContext(), gpsCollectorSingleton);
    }
}

@Override
protected void onPause() {
    super.onPause();
    this.finish();
}

@Override
public void onClick(View v) {
    Intent intent;
    switch (v.getId()) {
    case R.id.bStart:
        startDataCollector();
        break;
    case R.id.bStatisticsStart:
        intent = new Intent(this, StatisticsActivity.class);
        startActivity(intent);
        break;
    }
}

private void startDataCollector() {
    if (((GreenEnergyApplication) getApplication()).getStartPreference(getApplicationContext()) == false) {
        controller.datahandlerObserver(getApplicationContext(), gpsCollectorSingleton); // Observer
        ((GreenEnergyApplication) getApplication()).setStartPreference(getApplicationContext(), true);
    }
    Intent intent = new Intent(this, WaysActivity.class);
    startActivity(intent);
}

SelectTransport Activity :

public class SelectTransportActivity extends BaseActivity implements OnItemClickListener {

GridView gridview;
private static int DATABASE_ID_OFFSET = 2;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_ways);

    gridview = (GridView) findViewById(R.id.gridview);
    gridview.setAdapter(new ImageAdapter(this));
    gridview.setOnItemClickListener(this);
}

@Override
protected void onPause() { 
    super.onPause();
    this.finish();
}



@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
    ((GreenEnergyApplication)getApplication()).setTransportationPreference(getApplicationContext(), arg2+DATABASE_ID_OFFSET);
    Log.i("WayActivity",
            "ARG0: " + arg0.toString() + " Arg1: " + arg1.toString() + " "
                    + " Arg2: " + arg2 + " Arg3: " + arg3);
    Intent i = new Intent(this, StopActivity.class);
    startActivity(i);
}
}

停止 Activity :

public class StopActivity extends StartActivity implements OnClickListener, Observer {

Button stopButton, statsButton;
TextView statusTextView;
int distance, time, transportTypeEstimate, transportType;
int sessionStartTime = 0;
int sessionStartDistance = 0;
GPSCollectorSingleton gpsCollectorSingleton;
LocationData location;
boolean transportEstimation;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    GPSCollectorSingleton gps = GPSCollectorSingleton.getInstance();

    if (((GreenEnergyApplication) getApplication()).getStartPreference(getApplicationContext()) == false) {
        Log.i("STOP - STOP", "hasspeed");
        stopDataCollector();
    }

    setContentView(R.layout.activity_stop);

    stopButton = (Button) findViewById(R.id.bStop);
    statsButton = (Button) findViewById(R.id.bStatisticsStop);
    statusTextView = (TextView) findViewById(R.id.tvStatus);

    stopButton.setOnClickListener(this);
    statsButton.setOnClickListener(this);

    gpsCollectorSingleton = GPSCollectorSingleton.getInstance(); // Init model
    gpsCollectorSingleton.addObserver(this); // Observe on models state

    initTransportTypeDetection();
}

/**
 * Initializes estimating of transport type or manually chosen transport type
 */
private void initTransportTypeDetection() {
    transportType = ((GreenEnergyApplication) getApplication())
            .getTransportationPreference(getApplicationContext());
    transportTypeEstimate = transportType;

    if (transportType == TransportationDefinerSingleton.TRANSPORT_UNKNOWN) { // Start transport type estimation
        TransportationDefinerSingleton transport = TransportationDefinerSingleton.getInstance(); // Get model
        transport.addObservable(gpsCollectorSingleton); // Add observer for estimating transport type
        transportEstimation = true;
    } else { // Transport type manually specified
        setSessionStartDistanceAndTime();
        transportEstimation = false;
    }
}

private void setSessionStartDistanceAndTime() {
    Controller controller = new Controller();
    Database database = new Database(getApplicationContext());
    controller.controlDatabase(database);

    sessionStartDistance = controller.getDistanceFromID(transportType);
    sessionStartTime = controller.getTimeFromID(transportType);
}

@Override
public void onClick(View v) {
    Intent intent;
    switch (v.getId()) {
    case R.id.bStop:
        stopDataCollector();
        break;
    case R.id.bStatisticsStop:
        intent = new Intent(this, StatisticsActivity.class);
        startActivityForResult(intent, -1);
        break;
    }
}

private void stopDataCollector() {
    ((GreenEnergyApplication) getApplication()).setTransportationPreference(getApplicationContext(),
            TransportationDefinerSingleton.TRANSPORT_UNKNOWN);
    ((GreenEnergyApplication) getApplication()).setStartPreference(getApplicationContext(), false);

    gpsCollectorSingleton.deleteObservers(); // Delete all observers

    Controller controller = new Controller();
    Database database = new Database(getApplicationContext());
    controller.controlDatabase(database);
    // Get unknown data. From estimate of transport type or data collected while deciding transport type.
    int distance = controller.getDistanceFromID(TransportationDefinerSingleton.TRANSPORT_UNKNOWN);
    int time = controller.getTimeFromID(TransportationDefinerSingleton.TRANSPORT_UNKNOWN);

    if (transportEstimation) { // Estimate
        controller.updateTable(transportTypeEstimate, distance, time);
    } else { // Manually chosen transport type
        controller.updateTable(transportType, distance, time);
    }
    controller.resetTable(TransportationDefinerSingleton.TRANSPORT_UNKNOWN);

    Intent intent = new Intent(this, StartActivity.class);
    startActivity(intent);
    this.finish();
}

@Override
public void update(Observable observable, Object data) {
    Controller controller = new Controller();
    Database database = new Database(getApplicationContext());
    controller.controlDatabase(database);
    transportTypeEstimate = getTransportType();
    distance = controller.getDistanceFromID(transportType) - sessionStartDistance;
    time = controller.getTimeFromID(transportType) - sessionStartTime;
    location = (LocationData) data;

    runOnUiThread(new Runnable() {
        @Override
        public void run() {
            String transportName = getTransportName(transportTypeEstimate);
            statusTextView.setText("Transport type: " + transportName + " Distance: " + distance + " Time: " + time
                    + "\nTimeStamp: " + location.getTime() + "\nSpeed: " + location.getSpeed()
                    + " Seconds since last: " + location.getSecondsSinceLastSample());
        }
    });
}

private int getTransportType() {
    if (transportEstimation) {
        TransportationDefinerSingleton transport = TransportationDefinerSingleton.getInstance();
        Controller controller = new Controller();
        controller.controlTransportationDefinerSingleton(transport);
        transportTypeEstimate = controller.getTransportType();
    }
    return transportTypeEstimate;
}

private String getTransportName(int type) {
    switch (type) {
    case TransportationDefinerSingleton.TRANSPORT_UNKNOWN:
        return "Unknown";
    case TransportationDefinerSingleton.TRANSPORT_WALK:
        return "Walking";
    case TransportationDefinerSingleton.TRANSPORT_BIKE:
        return "Bike";
    case TransportationDefinerSingleton.TRANSPORT_CAR:
        return "Car";
    case TransportationDefinerSingleton.TRANSPORT_BUS:
        return "Bus";
    case TransportationDefinerSingleton.TRANSPORT_TRAIN:
        return "Train";
    case TransportationDefinerSingleton.TRANSPORT_MOTORCYCLE:
        return "Motor Cycle";
    case TransportationDefinerSingleton.TRANSPORT_CARPOOL:
        return "Carpool";
    }
    return "";
}

Base Activity ，它是其他 Activity 的父类(super class)。它只是设置选项菜单和其他基本内容。

public class BaseActivity extends Activity {
private Controller controller;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    GPSCollectorSingleton gpsCollectorSingleton = GPSCollectorSingleton.getInstance(); // Init model
    controller = new Controller();
    controller.controlGPSCollectorSingleton(gpsCollectorSingleton); // Init controller
}

protected ServiceConnection funfManagerConn = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName name, IBinder service) {
        Log.i("OnServiceConnected", "MainActivity");
        controller.onServiceConnected(service);
    }

    @Override
    public void onServiceDisconnected(ComponentName name) {
        controller.onServiceDisconnected();
    }
};

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main, menu);
    return super.onCreateOptionsMenu(menu);

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.action_settings:
        disableService();
        closeActivity();
        return true;
    case R.id.action_clear:
        Database database = new Database(getApplicationContext());
        database.dropTable();
        return true;
    case R.id.action_toggle_auto:
        if (item.isChecked()) {
            item.setChecked(false);
            ((GreenEnergyApplication) getApplication()).setAutoPreference(getApplicationContext(), false);
        } else {
            item.setChecked(true);
            ((GreenEnergyApplication) getApplication()).setAutoPreference(getApplicationContext(), true);
        }
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}

@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    super.onPrepareOptionsMenu(menu);
    if (((GreenEnergyApplication) getApplication()).getAutoPreference(getApplicationContext()) == true) {
        menu.findItem(R.id.action_toggle_auto).setChecked(true);
    }
    return true;
}

/**
 * Disables the service and the pipeline
 */
private void disableService() {
    controller.disablePipeline(); // Disable pipeline
    boolean isBound = false;
    isBound = getApplicationContext().bindService(new Intent(getApplicationContext(), FunfManager.class),
            funfManagerConn, BIND_AUTO_CREATE);
    if (isBound) {
        getApplicationContext().unbindService(funfManagerConn); // Disable
                                                                // service
    }
}

private void closeActivity() {
    this.finish();
}
}

Answer 1

让我们从简单的事情开始:您的 StopActivity 扩展 StartActivity

public class StopActivity extends StartActivity {...

它应该扩展 BaseActivity 或调用 super.onCreate() 将运行 StartActivity.onCreate() 中的代码。