Android实现极简打开摄像头
作者:哒哒呵
这篇文章主要为大家详细介绍了Android实现极简打开摄像头,文中示例代码介绍的非常详细,具有一定的参考价值,感兴趣的小伙伴们可以参考一下
很多时候忘记Android摄像头如何打开,查看google文档的话,发现太复杂(只是单纯的想打开摄像头而已,不想添加那么多设置,添加那么功能),很多博客也是对官方文档的小修小改,连方法名都一样,因此,我决定完成Android相机最简单的打开摄像头(仅仅打开)。很久没用忘掉的话,打开链接复制粘贴一下就完事了。
AndroidManifest.xml设置CAMERA权限后,在代码中还要设置权限检查,但是因为我连权限检查都懒得加了,装好后直接在手机系统里手动允许权限。
Camera1(已废弃):
xml中使用SurfaceView作为预览View
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <SurfaceView android:id="@+id/surfaceView" android:layout_width="0dp" android:layout_height="0dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>
MainActivity:
public class MainActivity extends AppCompatActivity implements SurfaceHolder.Callback{ private SurfaceHolder holder; private Camera camera; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.activity_main); SurfaceView surfaceView = findViewById(R.id.surfaceView); holder = surfaceView.getHolder(); holder.addCallback(this); } @Override public void surfaceCreated(SurfaceHolder holder) { if(camera == null){ try { camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK); camera.setPreviewDisplay(holder); camera.startPreview(); Camera.Parameters parameters = camera.getParameters(); parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO); parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO); camera.setParameters(parameters); camera.setDisplayOrientation(90); }catch (Exception e){ e.printStackTrace(); } } } }
这样就完成了最简单的打开摄像头并在手机中出现画面。(代码里去掉2个接口中未实现的方法)
Camera2
Android 5.0(API 21)以后,谷歌就决定废弃原有的Camera API改用Camera2 API,因为功能更强大
xml使用TextureView作为预览(其实SurfaceView也行,官方的Demo是用TextureView的一个子类):
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <TextureView android:id="@+id/surfaceView" android:layout_width="0dp" android:layout_height="0dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>
MainActivity:
public class MainActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener { private TextureView textureView; private CaptureRequest.Builder builder; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); textureView = findViewById(R.id.surfaceView); textureView.setSurfaceTextureListener(this); } @Override public void onSurfaceTextureAvailable(final SurfaceTexture surface, int width, int height) { CameraManager manager = (CameraManager) getSystemService(CAMERA_SERVICE); if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) { return; } try { manager.openCamera("0", new CameraDevice.StateCallback() { @Override public void onOpened(@NonNull CameraDevice camera) { try { SurfaceTexture surfaceTexture = textureView.getSurfaceTexture(); surfaceTexture.setDefaultBufferSize(1440,1080); Surface surface = new Surface(surfaceTexture); builder = camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW); builder.addTarget(surface); camera.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() { @Override public void onConfigured(@NonNull CameraCaptureSession session) { try { session.setRepeatingRequest(builder.build(), null, null); } catch (CameraAccessException e) { e.printStackTrace(); } } @Override public void onConfigureFailed(@NonNull CameraCaptureSession session) { } }, null); } catch (CameraAccessException e) { e.printStackTrace(); } } @Override public void onDisconnected(@NonNull CameraDevice camera) { } @Override public void onError(@NonNull CameraDevice camera, int error) { } }, null); } catch (CameraAccessException e) { e.printStackTrace(); } } }
这样就成功使用Camera2的API打开并预览了(代码里去掉3个接口中未实现的方法)
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。