android camera2 分辨率代码如何写

以下是使用Android Camera2 API设置相机分辨率的示例代码：

1. 首先，在您的AndroidManifest.xml文件中添加相机和相机权限：

<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.CAMERA" />

2. 在您的活动中实现相机回调和相机状态回调：

public class CameraActivity extends AppCompatActivity {

    private CameraManager cameraManager;
    private String cameraId;
    private CameraDevice cameraDevice;
    private CameraCaptureSession cameraCaptureSession;
    private CaptureRequest.Builder captureRequestBuilder;
    private ImageReader imageReader;

    private static final int IMAGE_WIDTH = 640;
    private static final int IMAGE_HEIGHT = 480;

    // ...

    private final CameraDevice.StateCallback cameraStateCallback = new CameraDevice.StateCallback() {
        @Override
        public void onOpened(@NonNull CameraDevice camera) {
            cameraDevice = camera;
            createCaptureSession();
        }

        @Override
        public void onDisconnected(@NonNull CameraDevice camera) {
            cameraDevice.close();
        }

        @Override
        public void onError(@NonNull CameraDevice camera, int error) {
            cameraDevice.close();
            cameraDevice = null;
        }
    };

    private final CameraCaptureSession.StateCallback captureSessionStateCallback = new CameraCaptureSession.StateCallback() {
        @Override
        public void onConfigured(@NonNull CameraCaptureSession session) {
            cameraCaptureSession = session;
            updatePreview();
        }

        @Override
        public void onConfigureFailed(@NonNull CameraCaptureSession session) {
            Toast.makeText(CameraActivity.this, "Capture session failed", Toast.LENGTH_SHORT).show();
        }
    };

    // ...
}

3. 在您的活动的onCreate方法中获取相机管理器，并获取相机ID：

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

    cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);

    try {
        cameraId = cameraManager.getCameraIdList()[0];
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }

    // ...
}

4. 在您的活动中创建相机预览和图像读取器：

private void createPreview() {
    SurfaceTexture surfaceTexture = textureView.getSurfaceTexture();
    surfaceTexture.setDefaultBufferSize(IMAGE_WIDTH, IMAGE_HEIGHT);

    Surface previewSurface = new Surface(surfaceTexture);
    Surface imageSurface = imageReader.getSurface();

    try {
        captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
        captureRequestBuilder.addTarget(previewSurface);
        captureRequestBuilder.addTarget(imageSurface);

        cameraDevice.createCaptureSession(Arrays.asList(previewSurface, imageSurface), captureSessionStateCallback, null);

    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

private void createImageReader() {
    imageReader = ImageReader.newInstance(IMAGE_WIDTH, IMAGE_HEIGHT, ImageFormat.JPEG, 1);
    imageReader.setOnImageAvailableListener(imageReaderListener, null);
}

5. 在您的活动中更新相机预览：

private void updatePreview() {
    if (cameraDevice == null) {
        return;
    }

    captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);

    HandlerThread handlerThread = new HandlerThread("Preview");
    handlerThread.start();
    Handler handler = new Handler(handlerThread.getLooper());

    try {
        cameraCaptureSession.setRepeatingRequest(captureRequestBuilder.build(), null, handler);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

6. 最后，在您的活动的onResume方法中打开相机并创建相机预览和图像读取器：

@Override
protected void onResume() {
    super.onResume();

    try {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            return;
        }

        cameraManager.openCamera(cameraId, cameraStateCallback, null);
        createPreview();
        createImageReader();
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

注意：此示例代码仅适用于设置相机分辨率。如果您需要更多相机功能，例如对焦和曝光控制，请参考Camera2 API文档。