选择与Android CameraX一起使用的torch

dependencies {
    def camerax_version = "1.1.0-alpha07"
    implementation "androidx.camera:camera-camera2:$camerax_version"
    implementation "androidx.camera:camera-lifecycle:$camerax_version"
    implementation "androidx.camera:camera-view:1.0.0-alpha23"
}

<androidx.camera.view.CameraView
    android:id="@+id/cameraView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

class CameraFragment : Fragment() {
    private lateinit var cameraView: CameraView
    private lateinit var camera: Camera

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        cameraView = view.findViewById(R.id.cameraView)
        cameraView.bindToLifecycle(viewLifecycleOwner)

        camera = cameraView.camera
    }

    // 在需要开启或关闭torch的地方调用该方法
    private fun toggleTorch() {
        val cameraControl = camera.cameraControl
        val torchState = camera.cameraInfo.torchState.value

        if (torchState == TorchState.ON) {
            cameraControl.enableTorch(false)
        } else {
            cameraControl.enableTorch(true)
        }
    }
}