在CameraX（1.0.0-alpha06）上的takePicture需要执行程序

问题描述

从

androidx.camera:camera-core:1.0.0-alpha03

到

androidx.camera:camera-core:1.0.0-alpha06

setTargetAspectRatio方法的签名（在ImageCaptureConfig.Builder中）和takePicture（在ImageCapture中）已更改。

signatures of methods setTargetAspectRatio (in ImageCaptureConfig.Builder) and takePicture (in ImageCapture) have been changed.

网络上的官方文档和信息没有显示如何使用新方法（如何指定执行程序）。

Official documentation and info in web doesn't show how to use new methods (how to specify executor).

更新后破损的代码：

...
val captureConfig = ImageCaptureConfig.Builder()
    .setTargetAspectRatioCustom(Rational(1, 1)) //this method changed
    .setFlashMode(flashMode)
    .setLensFacing(lensFacing)
    .build()

val capture = ImageCapture(captureConfig)

binding.takeAPhoto.setOnClickListener {
    ...
    val imageFile = createTempFile(System.currentTimeMillis().toString(), ".jpg")
    capture.takePicture(imageFile, object : ImageCapture.OnImageSavedListener { //this method also changed

        override fun onImageSaved(file: File) {
            ...
        }

        override fun onError(useCaseError: ImageCapture.UseCaseError, message: String, cause: Throwable?) {
            ...
        })
    }
}

有人有（或知道在哪里找到）如何使用新方法的示例吗？
预先感谢

Does anyone have (or know where to find) example of how to use new methods?Thanks in advance

推荐答案

我面对的事情与您面临的一样。我从侧面解决了这个问题。

I faced same thing as you are facing. I resolved it from my side.

class MainActivity : AppCompatActivity(), Executor {
    private var right: Int = 0
    private var bottom: Int = 0
    private var left: Int = 0
    private var top: Int = 0
    private lateinit var preview: Preview
    private val REQUEST_CODE_PERMISSIONS = 10
    private val REQUIRED_PERMISSIONS = arrayOf(Manifest.permission.CAMERA)
    private lateinit var imageCapture: ImageCapture
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        if (allPermissionsGranted()) {
            viewFinder.post { startCamera() }
        } else {
            ActivityCompat.requestPermissions(this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS)
        }

        viewFinder.addOnLayoutChangeListener { _, _, _, _, _, _, _, _, _ ->
            updateTransform()
        }

        buttonPlus.setOnClickListener {
            if (right < 100) {
                right += 100
                bottom += 100
                left += 100
                top += 100
                val my = Rect(left, top, right, bottom)
                preview.zoom(my)
            }
        }

        buttonMinus.setOnClickListener {
            if (right > 0) {
                right -= 100
                bottom -= 100
                left -= 100
                top -= 100
                val my = Rect(left, top, right, bottom)
                preview.zoom(my)
            }
        }
    }

    @SuppressLint("RestrictedApi")
    private fun startCamera() {
        val metrics = DisplayMetrics().also { viewFinder.display.getRealMetrics(it) }
        val screenAspectRatio = Rational(metrics.widthPixels, metrics.heightPixels)
        val previewConfig = PreviewConfig.Builder().apply {
            setTargetAspectRatioCustom(screenAspectRatio)
            setTargetRotation(viewFinder.display.rotation)
        }.build()
        preview = Preview(previewConfig)
        preview.setOnPreviewOutputUpdateListener {
            val parent = viewFinder.parent as ViewGroup
            parent.removeView(viewFinder)
            parent.addView(viewFinder, 0)
            viewFinder.surfaceTexture = it.surfaceTexture
            updateTransform()
        }
        CameraX.bindToLifecycle(this, preview)

        captureImage()
    }

    @SuppressLint("RestrictedApi")
    private fun captureImage() {
        val imageCaptureConfig = ImageCaptureConfig.Builder()
                .apply {
                    setTargetAspectRatioCustom(Rational(1, 1))
                    setCaptureMode(ImageCapture.CaptureMode.MIN_LATENCY)
                }.build()
        imageCapture = ImageCapture(imageCaptureConfig)
        CameraX.bindToLifecycle(this, imageCapture)
        capture_button.setOnClickListener {
            val file = File(this.externalMediaDirs.first(), "${System.currentTimeMillis()}.jpg")
            imageCapture.takePicture(file, this, object : ImageCapture.OnImageSavedListener {
                override fun onImageSaved(file: File) {
                    val msg = "Photo capture succeeded: ${file.absolutePath}"
                    Log.d("CameraXApp", msg)
                }

                override fun onError(imageCaptureError: ImageCapture.ImageCaptureError, message: String, cause: Throwable?) {
                    val msg = "Photo capture failed: $message"
                    Log.e("CameraXApp", msg)
                    cause?.printStackTrace()
                }
            })
        }
    }

    override fun execute(command: Runnable) {
        command.run()
    }

    private fun updateTransform() {
        val matrix = Matrix()
        val centerX = viewFinder.width / 2f
        val centerY = viewFinder.height / 2f
        val rotationDegrees = when (viewFinder.display.rotation) {
            Surface.ROTATION_0 -> 0
            Surface.ROTATION_90 -> 90
            Surface.ROTATION_180 -> 180
            Surface.ROTATION_270 -> 270
            else -> return
        }
        matrix.postRotate(-rotationDegrees.toFloat(), centerX, centerY)
        viewFinder.setTransform(matrix)
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
        if (requestCode == REQUEST_CODE_PERMISSIONS) {
            if (allPermissionsGranted()) {
                viewFinder.post { startCamera() }
            } else {
                Toast.makeText(this, "Permissions not granted by the user.", Toast.LENGTH_SHORT).show()
                finish()
            }
        }
    }

    private fun allPermissionsGranted() = REQUIRED_PERMISSIONS.all {
        ContextCompat.checkSelfPermission(baseContext, it) == PackageManager.PERMISSION_GRANTED
    }


    override fun onDestroy() {
        super.onDestroy()
        imageCapture.let {
            CameraX.unbind(imageCapture)
        }
    }
}

输出为（当我在 onImageSaved 方法中打印日志时）

And the output is (As I print log in onImageSaved method)

Photo capture succeeded: /storage/emulated/0/Android/media/com.akshay.cameraxzoominoutdemo/1571052301192.jpg

它是对我来说很好，请尝试一下。

It's working fine for me, try out this.

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