Android 如何将ImageAnalyzer类连接到应识别二维码的类？

我有两门课：QrActivity，打开相机扫描qr码；BarcodeAnalyzer，图像分析程序。我用cameraX和ML套件来做

这就是我的活动：

package ge.softservice.nfcwithactivties

import android.Manifest
import android.content.pm.PackageManager
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.camera.core.*
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import kotlinx.android.synthetic.main.activity_qr.*
import java.io.File
import java.util.concurrent.ExecutorService
import java.util.concurrent.Executors


class QrActivity : AppCompatActivity() {
    private var preview: Preview? = null
    private var imageAnalyzer: ImageAnalysis? = null
    private var camera: Camera? = null

    private lateinit var outputDirectory: File
    private lateinit var cameraExecutor: ExecutorService

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

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_qr)

        // Request camera permissions
        if (allPermissionsGranted()) {
            startCamera()
        } else {
            ActivityCompat.requestPermissions(
                this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS
            )
        }

        //      outputDirectory = getOutputDirectory()

        cameraExecutor = Executors.newSingleThreadExecutor()
    }

    private fun startCamera() {

        val cameraProviderFuture = ProcessCameraProvider.getInstance(this)
        cameraProviderFuture.addListener(Runnable {
            // Used to bind the lifecycle of cameras to the lifecycle owner
            val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()


            // Preview
            preview = Preview.Builder()
                .build()

            // Select back camera
            val cameraSelector =
                CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build()

            try {
                // Unbind use cases before rebinding
                cameraProvider.unbindAll()

                // Bind use cases to camera
                camera = cameraProvider.bindToLifecycle(
                    this, cameraSelector, preview
                )
                preview?.setSurfaceProvider(viewFinder.createSurfaceProvider(/*camera?.cameraInfo*/))
            } catch (exc: Exception) {
                Log.e(TAG, "Use case binding failed", exc)
            }

        }, ContextCompat.getMainExecutor(this))
    }

    private fun takePhoto() {
        // TODO
    }

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

/*    fun getOutputDirectory(): File {
        val mediaDir = externalMediaDirs.firstOrNull()?.let {
            File(it, resources.getString(R.string.app_name)).apply { mkdirs() } }
        return if (mediaDir != null && mediaDir.exists())
            mediaDir else filesDir
    }*/

    companion object {
        private const val TAG = "CameraXBasic"
        private const val FILENAME_FORMAT = "yyyy-MM-dd-HH-mm-ss-SSS"
        private const val REQUEST_CODE_PERMISSIONS = 10
        private val REQUIRED_PERMISSIONS = arrayOf(Manifest.permission.CAMERA)
    }
}

若我把它放在现在的条形码分析器中，并没有错误，但结果值是灰色的，并没有使用

我找到了此项目，并尝试执行类似操作，但在我的项目中，它向我显示了错误：

我也尝试了本教程和其他教程，但很多东西我都不清楚：

我试图在BarcodeAnalyzer的QrActivty类中创建一个实例，但它显示了错误

我正在学习google的firebase ML工具包教程，但仍然不适合我：

---

那么，我如何将BarcodeAnalyzer类连接到QrActivity类，或者如何创建一个实例来识别qr代码？

要将图像分析器连接到相机，您需要添加一个已添加的用例；此处的预览用例：cameraProvider.BindtolifecCyclethis、cameraSelector、preview

您可以像这样创建analyzer的实例：

val analyzer = ImageAnalysis.Builder()
    .setTargetAspectRatio(AspectRatio.RATIO_16_9)
    .setTargetRotation(previewView.display.rotation)
    .build().also {
         it.setAnalyzer(Executors.newSingleThreadExecutor(), BarcodeAnalyzer())
     }

然后绑定此用例：

cameraProvider.bindToLifecycle(this, cameraSelector, preview, analyzer)

---

我应该把代码放在哪里？预览后，我将其放入startCamera方法。但此处：。setTargetRotationrotation是未解析的引用。这里是：cameraProvider.bindToLifecyclethis，cameraSelector，preview，analyzer cameraSelector是未解析的引用。分析器是单元而不是用例。不，我应该用图像分析仪而不是分析仪。但是对于这些未解决的引用，我应该怎么做呢？检查我的更新答案。旋转是设备的旋转，您可以为其放置previewView.display.rotation。现在previewView是未解析的引用。我将其添加为：lateinit var previewView:previewView，但它在出现空指针异常时崩溃。我试过：var previewView:previewView？=null，但如果使用取景器中使用的任何变量而不是previewViewI，则会崩溃。我更改了它，不再出现错误。但在条形码分析器类中，结果值仍然是灰色的，未使用。我如何能够访问QrActivity类中的该变量，或者如何使其工作？

val analyzer = ImageAnalysis.Builder()
    .setTargetAspectRatio(AspectRatio.RATIO_16_9)
    .setTargetRotation(previewView.display.rotation)
    .build().also {
         it.setAnalyzer(Executors.newSingleThreadExecutor(), BarcodeAnalyzer())
     }

cameraProvider.bindToLifecycle(this, cameraSelector, preview, analyzer)