java - Android上为什么不在Activity中调用onActivityResult

Question

在我的应用程序中，我想要一个录制屏幕，为此我编写了以下代码。
运行应用程序后，没有调用我的记录器服务，并且使用 Log.e 后它仍然不显示日志？
我将录制代码写入onActivityResult。

为此，我使用了 countDownTimer，并且我希望当该计时器完成时，开始录制。

为了检查它是否有效，我使用了 Log.e ，它显示了 onFinished 代码的日志(用于计时器)，但不显示 任何 log 到 onActivtyResult 代码

我的 Activity 代码:

public class RecordingActivity extends BaseActivity {

    private TextView txtTesterCounter;
    Thread thread;
    private int counter;
    private CountDownTimer countDownTimer;
    private MediaProjection mMediaProjection;
    private MediaProjectionManager mProjectionManager;

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

        init();

        reverseTimer(4).start();
        //Create video direction
        createDir();
    }

    private void init() {
        txtTesterCounter = findViewById(R.id.txtTesterCounter);
        counter = 3;
        //Acquiring media projection service to start screen mirroring
        mProjectionManager = (MediaProjectionManager) getSystemService(Context.MEDIA_PROJECTION_SERVICE);
    }

    private CountDownTimer reverseTimer(int second) {
        return countDownTimer = new CountDownTimer(second * 1000, 1000) {
            @SuppressLint("SetTextI18n")
            @Override
            public void onTick(long millisUntilFinished) {
                if (millisUntilFinished <= 800) {
                    onFinish();
                } else {
                    int second = (int) (millisUntilFinished / 1000);
                    txtTesterCounter.setText(App.enToFa(second + ""));
                }
            }

            @Override
            public void onFinish() {
                if (mMediaProjection == null && !isServiceRunning(RecorderService.class)) {
                    //Request Screen recording permission
                    startActivityForResult(mProjectionManager.createScreenCaptureIntent(), ConstKeys.SCREEN_RECORD_REQUEST_CODE);
                    Log.e("RecordingLog","OnFinished");
                } else if (isServiceRunning(RecorderService.class)) {
                    //stop recording if the service is already active and recording
                }
                finish();
            }
        };
    }

    //Create application directory
    public static void createDir() {
        File appDir = new File(Environment.getExternalStorageDirectory() + File.separator + ConstKeys.APPDIR);
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED) && !appDir.isDirectory()) {
            appDir.mkdirs();
        }
    }

    private boolean isServiceRunning(Class<?> serviceClass) {
        ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
        for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
            if (serviceClass.getName().equals(service.service.getClassName())) {
                return true;
            }
        }
        return false;
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        Log.e("RecordingLog","OnActivityResult");
        //The user has denied permission for screen mirroring. Let's notify the user
        if (resultCode == RESULT_CANCELED && requestCode == ConstKeys.SCREEN_RECORD_REQUEST_CODE) {
            return;
        }

        Intent recorderService = new Intent(this, RecorderService.class);
        recorderService.setAction(ConstKeys.SCREEN_RECORDING_START);
        recorderService.putExtra(ConstKeys.RECORDER_INTENT_DATA, data);
        recorderService.putExtra(ConstKeys.RECORDER_INTENT_RESULT, resultCode);
        startService(recorderService);
        Log.e("RecordingLog","Recorder Service");
    }
}

我该如何解决这个问题？

Answer 1

onActivityResult 在子 Activity 完成时调用。在您的情况下，开始 Activity 后，您将完成RecordingActivity。

@Override
public void onFinish() {
    if (mMediaProjection == null && !isServiceRunning(RecorderService.class)) {
        //Request Screen recording permission
        startActivityForResult(mProjectionManager.createScreenCaptureIntent(), ConstKeys.SCREEN_RECORD_REQUEST_CODE);
        Log.e("RecordingLog","OnFinished");
    } else if (isServiceRunning(RecorderService.class)) {
        //stop recording if the service is already active and recording
    }
    finish(); // what does this method do?
}

我假设完成方法完成了您的 Activity 。如果这样做，onActivityResult 将永远不会被调用，因为您完成了父 Activity。