问只需用CameraX切换闪存
EN

Stack Overflow用户

提问于 2020-05-13 06:25:08

回答 1查看 3.2K关注 0票数 7

对不起，我的英语说得不好。

我有一个应用程序，通过闪烁闪光灯与arduino设备进行通信。我注意到Camera1和Camera2在所有安卓设备上都有问题，所以我构建了一个设置屏幕，用户可以测试这两种设置，并选择一个工作正常的。

我现在正试图与CameraX建立同样的通信，希望它能在更多的设备中正常工作，但我找不到仅仅切换闪存的例子。我是android开发部的新手，我发现的材料只是关于拍照之类的，但我甚至不想打开相机屏幕，只要打开或关闭闪光灯，就像灯笼一样。

有人能帮上忙吗，或者发送一份帮助你的文档？

edit1

我在onCreate中这样做，我看到日志进入logcat，但闪存不切换。也许我需要造个案子？

lateinit var cameraControl: CameraControl
val cameraProcessFuture = ProcessCameraProvider.getInstance(this)
cameraProcessFuture.addListener(Runnable {
    val cameraProvider = cameraProcessFuture.get()

    val lifecycleOwner = this

    val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

    val camera = cameraProvider.bindToLifecycle(lifecycleOwner, cameraSelector)

    cameraControl = camera.cameraControl


    val listenableFuture = cameraControl!!.enableTorch(true)

    // cameraControl.enableTorch(false)
    Log.d("MurilloTesteCamera", "listener")
    listenableFuture.addListener(Runnable {

        Log.d("MurilloTesteCamera", "listener 2")
    }, ContextCompat.getMainExecutor(this))

}, ContextCompat.getMainExecutor(this))
Log.d("MurilloTesteCamera", "oncreate")

edit2

这段代码我试图创建一个案例，但没有解决我的问题，闪存也没有打开(我的活动实现了CameraXConfig.Provider：

val context = this

Log.d("MurilloTesteCamera", "before initialize")
CameraX.initialize(context, cameraXConfig).addListener(Runnable {

    Log.d("MurilloTesteCamera", "inside initialize")


    CameraX.unbindAll()

    val preview = Preview.Builder()
        .apply {
            setTargetResolution(Size(640, 480))
        }
        .build()


    lateinit var cameraControl: CameraControl

    val cameraProcessFuture = ProcessCameraProvider.getInstance(context)
    cameraProcessFuture.addListener(Runnable {
        val cameraProvider = cameraProcessFuture.get()

        val lifecycleOwner = context

        val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

        val camera = cameraProvider.bindToLifecycle(lifecycleOwner, cameraSelector)

        cameraControl = camera.cameraControl

        camera.cameraInfo.hasFlashUnit()

        Log.d("MurilloTesteCamera", "info before -> " + camera.cameraInfo.torchState)
        Log.d("MurilloTesteCamera", "has flash -> " + camera.cameraInfo.hasFlashUnit())



        val listenableFuture = cameraControl.enableTorch(true)

        Log.d("MurilloTesteCamera", "listener")
        listenableFuture.addListener(Runnable {
            Log.d("MurilloTesteCamera", "info after -> " + camera.cameraInfo.torchState)

            Log.d("MurilloTesteCamera", "listener 2")
        }, ContextCompat.getMainExecutor(context))

        CameraX.bindToLifecycle(context, cameraSelector, preview)

    }, ContextCompat.getMainExecutor(context))



}, ContextCompat.getMainExecutor(context))

Log.d("MurilloTesteCamera", "after initialize")
while (!CameraX.isInitialized()){}
Log.d("MurilloTesteCamera", "after while")

android

kotlin

android-camerax

回答 1

Stack Overflow用户

发布于 2020-05-13 08:02:31

在CameraX中，打开/关闭相机火炬的API是CameraControl.enableTorch(boolean)。要获得一个CameraControl实例，您可以遵循以下文档：

应用程序可以通过Camera.getCameraControl()检索CameraControl实例。CameraControl已准备好在获取摄像机并将UseCases绑定到该摄像机后立即开始操作。

这意味着您首先需要将一个用例(或多个用例)绑定到一个生命周期。您提到了不想使用open a camera screen，所以我假设您不想绑定任何用例，在这种情况下，您可以使用零用例调用bindToLifecycle()。这可能适用于CameraX的最新版本，也可能不适用。

总之，你必须写这样的东西：

val cameraProcessFuture = ProcessCameraProvider.getInstance(context)
cameraProcessFuture.addListener(Runnable {
    val cameraProvider = cameraProcessFuture.get()

    // Choose the lifecycle to which the camera will be attached to
    val lifecycleOwner = /* Can be an Activity, Fragment, or a custom lifecycleOwner */

    // Choose a valid camera the device has
    val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

    // You might need to create a use case to start capture requests 
    // with the camera
    val imageAnalysis = ImageAnalysis.Builder()
          .build()
          .apply {
              val executor = /* Define an executor */
              setAnalyzer(executor, ImageAnalysis.Analyzer {
                  it.close()
              })
           }

    // Get a camera instance
    val camera = cameraProvider.bindToLifecycle(lifecycleOwner, cameraSelector)

    // Get a cameraControl instance
    val cameraControl = camera.cameraControl

    // Call enableTorch(), you can listen to the result to check whether it was successful
    cameraControl.enableTorch(true) // enable torch
    cameraControl.enableTorch(false) // disbale torch
}, ContextCompat.getMainExecutor(context))