我是一个新手，并试图建立一个基于https://inducesmile.com/android/android-camera2-api-example-tutorial/的应用程序，以帮助一个难以看见的个人。我需要使用蓝牙游戏控制器实时控制缩放级别 - 按下按钮时，缩放级别会发生变化。我删除了＆＃34;拍照＆＃34;按钮和顶部横幅，以便我可以使用全屏。我试图用不同的方法更改缩放级别：createCameraPreview，updatePreview和dispatchKeyEvent但它不起作用。我应该在哪里应用新的captureRequestBuilder和更新的缩放Rect？感谢。
+import ...
public class AndroidCameraApi extends AppCompatActivity {
private static final String TAG = "AndroidCameraApi";
private TextureView textureView;
private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
static {
ORIENTATIONS.append(Surface.ROTATION_0, 90);
ORIENTATIONS.append(Surface.ROTATION_90, 0);
ORIENTATIONS.append(Surface.ROTATION_180, 270);
ORIENTATIONS.append(Surface.ROTATION_270, 180);
}
private String cameraId;
protected CameraDevice cameraDevice;
protected CameraCaptureSession cameraCaptureSessions;
protected CaptureRequest captureRequest;
protected CaptureRequest.Builder captureRequestBuilder;
private Size imageDimension;
private ImageReader imageReader;
private File file;
private static final int REQUEST_CAMERA_PERMISSION = 200;
private boolean mFlashSupported;
private Handler mBackgroundHandler;
private HandlerThread mBackgroundThread;
private int kc; //kc is keyCode from bluetooth controller
Rect zoomCropPreview = new Rect(1094, 822, 2186, 1642); //zoomed in
//Rect zoomCropPreview = new Rect(0,0,4032,3024); //full screen
@Override
protected void onCreate(Bundle savedInstanceState) { //onCreate set up layout, texture, take pciture button
super.onCreate(savedInstanceState);
//this.requestWindowFeature(Window.FEATURE_NO_TITLE); //remove title bar
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); //remove notification mar
setContentView(R.layout.activity_android_camera_api);
textureView = (TextureView) findViewById(R.id.texture); //set up texture
assert textureView != null;
textureView.setSurfaceTextureListener(textureListener);
}
TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
//open your camera here
openCamera();
}
};
private void openCamera() {
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
Log.e(TAG, "is camera open");
try {
cameraId = manager.getCameraIdList()[0];
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
Float maxDigitalZoom = characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM); //get maximum digital zoom (=8)
Rect asd = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
assert map != null;
imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
// Add permission for camera and let user grant the permission
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(AndroidCameraApi.this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CAMERA_PERMISSION);
return;
}
manager.openCamera(cameraId, stateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
Log.e(TAG, "openCamera X");
}
private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice camera) {
//This is called when the camera is open
Log.e(TAG, "onOpened");
cameraDevice = camera;
createCameraPreview();
}
@Override
public void onDisconnected(CameraDevice camera) {
cameraDevice.close();
}
@Override
public void onError(CameraDevice camera, int error) {
cameraDevice.close();
cameraDevice = null;
}
};
protected void createCameraPreview() {
try {
SurfaceTexture texture = textureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
Surface surface = new Surface(texture);
captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureRequestBuilder.addTarget(surface);
//try to change zoom- didn't work
//captureRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoomCropPreview);
cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
//The camera is already closed
if (null == cameraDevice) {
return;
}
// When the session is ready, we start displaying the preview.
//try to change zoom here- didn't work
//captureRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoomCropPreview);
cameraCaptureSessions = cameraCaptureSession;
updatePreview(); //update preview screen
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Toast.makeText(AndroidCameraApi.this, "Configuration change", Toast.LENGTH_SHORT).show();
}
}, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
protected void updatePreview() {
if (null == cameraDevice) {
Log.e(TAG, "updatePreview error, return");
}
// Original
//captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
//Modified
captureRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoomCropPreview);
try {
cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
//********************************
// Change zoom based on Bluetooth controller
//********************************
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
kc = event.getKeyCode();
Log.i("key pressed", String.valueOf(kc));
//as a test, just change from zoomed in to full screen
zoomCropPreview.set(0,0,4032,3024); //change to full screen
Log.i("zoomCropPreview", (zoomCropPreview).flattenToString());
//try to change zoom- didn't work
captureRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoomCropPreview);
return super.dispatchKeyEvent(event);
}
final CameraCaptureSession.CaptureCallback captureCallbackListener = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
super.onCaptureCompleted(session, request, result);
Toast.makeText(AndroidCameraApi.this, "Saved:" + file, Toast.LENGTH_SHORT).show();
createCameraPreview();
}
};
protected void startBackgroundThread() {
mBackgroundThread = new HandlerThread("Camera Background");
mBackgroundThread.start();
mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
}
protected void stopBackgroundThread() {
mBackgroundThread.quitSafely();
try {
mBackgroundThread.join();
mBackgroundThread = null;
mBackgroundHandler = null;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private void closeCamera() {
if (null != cameraDevice) {
cameraDevice.close();
cameraDevice = null;
}
if (null != imageReader) {
imageReader.close();
imageReader = null;
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == REQUEST_CAMERA_PERMISSION) {
if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
// close the app
Toast.makeText(AndroidCameraApi.this, "Sorry!!!, you can't use this app without granting permission", Toast.LENGTH_LONG).show();
finish();
}
}
}
@Override
protected void onResume() {
super.onResume();
Log.e(TAG, "onResume");
startBackgroundThread();
if (textureView.isAvailable()) {
openCamera();
} else {
textureView.setSurfaceTextureListener(textureListener);
}
}
@Override
protected void onPause() {
Log.e(TAG, "onPause");
//closeCamera();
stopBackgroundThread();
super.onPause();
}
}
答案 0 :(得分：2)
在更新了captureRequestBuilder中的所有设置后，您需要再次调用cameraCaptureSessions.setRepeatingRequest。
只是更新构建器本身不会做任何事情，它只是修改一组设置。你需要告诉相机实际使用新的捆绑包来发生任何事情。