我有一个简单的活动，可以启动和停止记录 GPS 数据的后台服务。然后我通过单击主页按钮将该过程置于后台。
当我通过单击它的图标返回应用程序时，它会创建一个新进程而不是恢复到原始活动。如果我然后关闭此过程（通过单击后退按钮），它会调用 onDestroy() 然后恢复到我原来的活动屏幕，显示该服务仍在录制。这对于应用程序的预期用途非常不便。
我的理解是应该从活动堆栈中弹出原始活动，而不是创建一个新进程。
下面是我的活动代码。我将不胜感激任何人对此的解释。
public class MainActivity extends Activity {
GPSTracker gps;
private static final String TAG = "MEDIA";
private String tv;
private boolean record = false;
private TextView status = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null)
record = savedInstanceState.getBoolean("Status");
Toast.makeText(getApplicationContext(),"onCreate",Toast.LENGTH_LONG).show();
setContentView(R.layout.activity_main);
}
public void StartRecord(View v) {
Button btn = (Button) findViewById(R.id.record);
status = (TextView) findViewById(R.id.status);
if (record == false) {
btn.setText("Stop Record");
status.setText("... Recording ...");
record = true;
ComponentName comp = new ComponentName(getPackageName(), LogService.class.getName());
ComponentName service = startService(new Intent().setComponent(comp));
}
else {
record = false;
status.setText("... Standing By ...");
stopService(new Intent(MainActivity.this,LogService.class));
btn.setText("Start Record");
}
}
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
Toast.makeText(getApplicationContext(), "onSaveInstanceState",Toast.LENGTH_LONG).show();
savedInstanceState.putBoolean("Status", record);
// etc.
}
@Override
public void onResume() {
super.onResume(); // Always call the superclass method first
Button btn = (Button) findViewById(R.id.record);
Toast.makeText(getApplicationContext(), "onResume",Toast.LENGTH_LONG).show();
if (record == true)
btn.setText("Stop Record");
else
btn.setText("Start Record");
}
@Override
public void onStart() {
super.onStart(); // Always call the superclass method first
Toast.makeText(getApplicationContext(), "onStart",Toast.LENGTH_LONG).show();
}
@Override
public void onRestart() {
super.onRestart(); // Always call the superclass method first
Toast.makeText(getApplicationContext(), "onRestart",Toast.LENGTH_LONG).show();
}
@Override
public void onDestroy() {
super.onDestroy(); // Always call the superclass method first
Toast.makeText(getApplicationContext(), "onDestroy",Toast.LENGTH_LONG).show();
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// Restore UI state from the savedInstanceState.
// This bundle has also been passed to onCreate.
Toast.makeText(getApplicationContext(), "onRestoreInstanceState",Toast.LENGTH_LONG).show();
record = savedInstanceState.getBoolean("Status");
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}