安卓获取手电筒状态和开关手电筒

2021-06-26

字数统计:437字阅读时长≈2分

这个是之前为努比亚Mini5G制作的小程序屏蔽相机按键的手电筒部分，整理文件时发现的源码还留着，记录一下，软件在酷安获取

开关手电筒

调用闪光灯硬件先申请权限

1 2	<uses-permission android:name="android.permission.FLASHLIGHT" /> <uses-permission android:name="android.permission.CAMERA"/>

开关手电筒

private CameraManager manager;
private Camera camera;

@Override
protected void onCreate(Bundle savedInstanceState){
  super.onCreate(savedInstanceState);
  ...
  if(manager == null){
    manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
  }
  ...
}

private void openFlash() {
  try {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
      if (manager != null) {
        manager.setTorchMode("0", true);
      }
    } else {
      camera = Camera.open();
      Camera.Parameters parameters = camera.getParameters();
      parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
      camera.setParameters(parameters);
      camera.startPreview();
    }
  } catch (Exception e) {
    e.printStackTrace();
  }
}

private void closeFlash() {
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    try {
      if (manager == null) {
        return;
      }
      manager.setTorchMode("0", false);
    } catch (Exception e) {
      e.printStackTrace();
    }
  } else {
    if (camera == null) {
      return;
    }
    camera.stopPreview();
    camera.release();
  }
}

上面开关手电筒部分用到了 Mason-Xu/JustAFlashLight 项目的源码

获取手电筒状态

接上面代码，用下面这个可以在回调中获取手电筒状态

1	manager.registerTorchCallback(torchCallback, null);

获取到手电筒状态进行开启关闭操作

private CameraManager.TorchCallback torchCallback = new CameraManager.TorchCallback() {
  @Override
  public void onTorchModeChanged( String cameraId, boolean enabled) {
    super.onTorchModeChanged(cameraId, enabled);
    manager.unregisterTorchCallback(torchCallback);
    if(!enabled){
      //手电筒状态关闭，执行开启
      openFlash();
    } else {
      //手电筒状态开启，执行关闭
      closeFlash();
    }
  }
};

@Override
protected void onDestroy() {
  super.onDestroy();
  if(manager != null && torchCallback != null){
    manager.unregisterTorchCallback(torchCallback);
  }
}

获取到手电筒状态直接操作手电筒有时会闪烁直接关闭，经测试可以用下面代码解决

1	manager.unregisterTorchCallback(torchCallback);

获取手电筒状态，方法来自 android 9.0 获取手电筒状态以及打开/关闭手电筒