Android实现静默拍照功能

时间:2020-06-22 骑驴望星空人气:1

本文着重为大家仔细讲解了Android实现静默拍照，文中代码实例讲解的非常细致，希望能够帮助到您，欢迎大家阅读和收藏

1.申请权限（6.0以后要动态申请）

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

2.创建相机工具类 CameraPreview：

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
 private SurfaceHolder mHolder;
 private Camera mCamera;

 public CameraPreview(Context context, Camera camera) {
  super(context);
  //初始化Camera对象
  mCamera = camera;
  //得到SurfaceHolder对象
  mHolder = getHolder();
  //添加回调，得到Surface的三个声明周期方法
  mHolder.addCallback(this);
  // deprecated setting, but required on Android versions prior to 3.0
  mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
 }

 @Override
 public void surfaceCreated(SurfaceHolder holder) {
  try {
   //设置预览方向
   mCamera.setDisplayOrientation(90);
   //把这个预览效果展示在SurfaceView上面
   mCamera.setPreviewDisplay(holder);
   //开启预览效果
   mCamera.startPreview();
  } catch (IOException e) {
//   Log.d(TAG, "Error setting camera preview: " + e.getMessage());
  }

 }

 @Override
 public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
  if (holder.getSurface() == null) {
   return;
  }
  //停止预览效果
  mCamera.stopPreview();
  //重新设置预览效果
  try {
   mCamera.setPreviewDisplay(mHolder);
  } catch (IOException e) {
   e.printStackTrace();
  }
  mCamera.startPreview();
 }

 @Override
 public void surfaceDestroyed(SurfaceHolder holder) {

 }
}

3.创建xml文件（要想用户无感拍照，可把视图宽高调为0.1dp或者隐藏在别的页面之下）：

<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical">

 <FrameLayout
  android:id="@+id/camera_frame"
  android:layout_width="match_parent"
  android:layout_height="500dp">
 </FrameLayout>

</LinearLayout>

4.主类实现静默拍照：

public class CameraActivity extends BaseActivity{

 private FrameLayout cameraFrame;
 private Camera mCamera;
 private TextView cameraTv;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_camera);


  cameraFrame = (FrameLayout) findViewById(R.id.camera_frame);
  cameraTv = (TextView) findViewById(R.id.camera_tv);

  int numberOfCameras = Camera.getNumberOfCameras();// 获取摄像头个数
  //遍历摄像头信息
  for (int cameraId = 0; cameraId < numberOfCameras; cameraId++) {
   Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
   Camera.getCameraInfo(cameraId, cameraInfo);
   if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {//前置摄像头
    mCamera = Camera.open(cameraId);//打开摄像头
   }
  }

  CameraPreview mPreview = new CameraPreview(this, mCamera);
  cameraFrame.addView(mPreview);
  new Thread(new Runnable() {
   @Override
   public void run() {
    try {
     Thread.sleep(1000); // 设置1秒后自动拍照，可调节
     //得到照相机的参数
     Camera.Parameters parameters = mCamera.getParameters();
     //图片的格式
     parameters.setPictureFormat(ImageFormat.JPEG);
     //预览的大小是多少
     parameters.setPreviewSize(800, 400);
     //设置对焦模式，自动对焦
     parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
     //对焦成功后，自动拍照
     mCamera.autoFocus(new Camera.AutoFocusCallback() {
      @Override
      public void onAutoFocus(boolean success, Camera camera) {
       if (success) {
        //获取照片
        mCamera.takePicture(null, null, mPictureCallback);
       }
      }
     });
    } catch (InterruptedException e) {
     e.printStackTrace();
    }
   }
  }).start();

  });
 }

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

 }

 //获取照片中的接口回调
 Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
  @Override
  public void onPictureTaken(byte[] data, Camera camera) {
   FileOutputStream fos = null;
   String mFilePath = Environment.getExternalStorageDirectory().getPath() + File.separator + "tt005.png";
   //文件
   File tempFile = new File(mFilePath);
   try {
    //
    fos = new FileOutputStream(tempFile);
    fos.write(data);

   } catch (FileNotFoundException e) {
    e.printStackTrace();
   } catch (IOException e) {
    e.printStackTrace();
   } finally {
    //实现连续拍多张的效果
//    mCamera.startPreview();
//    if (fos != null) {
//     try {
//      fos.close();
//     } catch (IOException e) {
//      e.printStackTrace();
//     }
//    }
   }

  }
 };
}

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