由于图像已关闭，ML Kit Barcode 进程失败答案

【问题标题】：ML Kit Barcode process fails due to Image is already closed由于图像已关闭，ML Kit Barcode 进程失败
【发布时间】：2021-01-23 13:37:03
【问题描述】：

我正在寻找如何使用 ML Kit 和 CameraX 读取 QR 码的方法。输入图像的过程总是返回失败“IllegalStateException：图像已关闭”。我看过不同的论坛，但我找不到我做错了什么。我想我正在关注 Google 文档，但它不起作用。

这就是我在 MainActivity 中所做的：

我创建了一个纹理视图，它显示了我的相机的输入
我启动相机（检查必要的权限后）
我设置了一个“预览”用例
我设置了一个“图像分析”用例
我设置了一个分析器，该分析器创建一个 InputImage，该 InputImage 被传递给条形码扫描器进程
使用用例“预览”和“图像分析”设置我的生命周期

我使用的是 CameraX 版本“1.0.0-alpha04”和“com.google.mlkit:barcode-scanning:16.0.3”。

build.gradle

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.2"

    defaultConfig {
        applicationId "be.lapit.qrcodescanner"
        minSdkVersion 21
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation 'androidx.core:core-ktx:1.3.2'
    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'

    // ML Kit Barcode scanner
    implementation 'com.google.mlkit:barcode-scanning:16.0.3'
    implementation 'com.google.android.gms:play-services-mlkit-barcode-scanning:16.1.2'

    // CameraX
    def camerax_version = "1.0.0-alpha04"
    // The following line is optional, as the core library is included indirectly by camera-camera2
    implementation "androidx.camera:camera-core:${camerax_version}"
    implementation "androidx.camera:camera-camera2:${camerax_version}"
    // If you want to additionally use the CameraX Lifecycle library
    //implementation "androidx.camera:camera-lifecycle:${camerax_version}"
    // If you want to additionally use the CameraX View class
    //implementation "androidx.camera:camera-view:1.0.0-alpha17"

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
   xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   android:layout_width="match_parent"
   android:layout_height="match_parent">

   <LinearLayout
       android:id="@+id/linearLayout"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:gravity="center"
       android:orientation="vertical"
       app:layout_constraintBottom_toBottomOf="parent"
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintStart_toStartOf="parent">


       <ImageView
           android:id="@+id/imageView"
           android:layout_width="250px"
           android:layout_height="250px"
           android:layout_marginBottom="48dp"
           android:src="@drawable/thumb_up" />

       <TextView
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="Test textview"/>

       <TextureView
           android:id="@+id/texture_view"
           android:layout_width="600px"
           android:layout_height="600px" />


   </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.kt

package be.lapit.qrcodescanner

import android.Manifest
import android.content.Intent
import android.content.pm.PackageManager
import android.os.Bundle
import android.util.Log
import android.util.Size
import android.view.TextureView
import android.widget.Button
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.camera.core.*
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import androidx.lifecycle.LifecycleOwner
import com.google.android.gms.tasks.OnFailureListener
import com.google.mlkit.vision.barcode.Barcode
import com.google.mlkit.vision.barcode.BarcodeScannerOptions
import com.google.mlkit.vision.barcode.BarcodeScanning
import com.google.mlkit.vision.common.InputImage
import java.time.Instant
import java.time.format.DateTimeFormatter
import kotlin.system.measureTimeMillis


class MainActivity : AppCompatActivity() {

    // PLA: Variable needed to check if user has granted camera permission
    companion object {
        private const val REQUEST_CAMERA_PERMISSION = 10
    }

    private lateinit var textureView: TextureView

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

        textureView = findViewById(R.id.texture_view)

        // Request camera permissions
        if (isCameraPermissionGranted()) {
            textureView.post { startCamera() }
        } else {
            ActivityCompat.requestPermissions(
                this,
                arrayOf(Manifest.permission.CAMERA),
                REQUEST_CAMERA_PERMISSION
            )
        }


    }

    private fun startCamera() {
        // -----------------------
        // Setup use case Preview
        // -----------------------
        val previewConfig : PreviewConfig = PreviewConfig.Builder()
            // We want to show input from front camera of the device
            .setLensFacing(CameraX.LensFacing.FRONT)
            .build()

        val preview = Preview(previewConfig)

        preview.setOnPreviewOutputUpdateListener { previewOutput ->
            textureView.setSurfaceTexture(previewOutput.surfaceTexture)
        }

        // ------------------------------
        // Setup use case Image Analysis
        // ------------------------------
        val imageAnalysisConfig = ImageAnalysisConfig.Builder()
            .setTargetResolution(Size(1280, 720))
            .setLensFacing(CameraX.LensFacing.FRONT)
            .setImageReaderMode(ImageAnalysis.ImageReaderMode.ACQUIRE_LATEST_IMAGE)
            .setImageQueueDepth(1)
            .build()

        val imageAnalysis = ImageAnalysis(imageAnalysisConfig)

        // -------------------
        // Set image analyzer
        // -------------------
        imageAnalysis.setAnalyzer { imageProxy: ImageProxy, rotationDegrees: Int ->
            Log.i("Status", "In setAnalyzer on " + System.currentTimeMillis())

            val mediaImage = imageProxy.image
            if (mediaImage != null) {
                val image1 = InputImage.fromMediaImage(mediaImage, rotationDegrees)

                // --------------------------
                // Configure barcode scanner
                // --------------------------
                val barcodeScannerOptions: BarcodeScannerOptions = BarcodeScannerOptions.Builder()
                    .setBarcodeFormats(
                        Barcode.FORMAT_QR_CODE,
                        Barcode.FORMAT_AZTEC,
                        Barcode.FORMAT_EAN_13

                    )
                    .build()

                // Get an instance of BarcodeScanner
                val scanner = BarcodeScanning.getClient(barcodeScannerOptions)

                scanner.process(image1)
                    .addOnSuccessListener ({ barcodes ->
                        // Task completed successfully
                        Log.i("Status", "In success listener on timestamp " + System.currentTimeMillis())
                        for (barcode in barcodes) {
                            Log.i("Barcode", barcode.toString())
                        }
                        Toast.makeText(this,"Ik ben hier eindelijk",Toast.LENGTH_LONG).show();

                    })
                    .addOnFailureListener(OnFailureListener {
                        // Process failed
                        Log.i("Status", "In failure listener on " +  System.currentTimeMillis() + " because: $it")
                        Log.i("Failure", "$it")
                        it.printStackTrace()
                    })
                    .addOnCompleteListener {
                        Log.i("Status", "In complete listener on " +  System.currentTimeMillis())
                        //imageProxy.close()
                    }
            }
        }

        // Bind
        CameraX.bindToLifecycle(this as LifecycleOwner, preview, imageAnalysis)
    }


    private fun isCameraPermissionGranted(): Boolean {
        val selfPermission = ContextCompat.checkSelfPermission(
            baseContext,
            Manifest.permission.CAMERA
        )
        return selfPermission == PackageManager.PERMISSION_GRANTED
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<String>,
        grantResults: IntArray
    ) {
        if (requestCode == REQUEST_CAMERA_PERMISSION) {
            if (isCameraPermissionGranted()) {
                textureView.post { startCamera() }
            } else {
                Toast.makeText(this, "Camera permission is required.", Toast.LENGTH_SHORT).show()
                finish()
            }
        }
    }
}

记录信息

I/Status: In setAnalyzer on 1602190069609
I/tflite: Initialized TensorFlow Lite runtime.
I/native: barcode_detector_client.cc:238 Not using NNAPI
I/Status: In failure listener on 1602190069612 because: com.google.mlkit.common.MlKitException: Internal error has occurred when executing ML Kit tasks
I/Failure: com.google.mlkit.common.MlKitException: Internal error has occurred when executing ML Kit tasks
W/System.err: com.google.mlkit.common.MlKitException: Internal error has occurred when executing ML Kit tasks
        at com.google.mlkit.common.sdkinternal.ModelResource.zza(com.google.mlkit:common@@17.0.0:32)
        at com.google.mlkit.common.sdkinternal.zzl.run(com.google.mlkit:common@@17.0.0)
W/System.err:     at com.google.mlkit.common.sdkinternal.zzp.run(com.google.mlkit:common@@17.0.0:3)
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zzd(com.google.mlkit:common@@17.0.0:24)
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zza(com.google.mlkit:common@@17.0.0:30)
        at com.google.mlkit.common.sdkinternal.zzh.run(com.google.mlkit:common@@17.0.0)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
        at java.lang.Thread.run(Thread.java:762)
    Caused by: java.lang.IllegalStateException: Image is already closed
        at android.media.Image.throwISEIfImageIsInvalid(Image.java:68)
        at android.media.ImageReader$SurfaceImage$SurfacePlane.getBuffer(ImageReader.java:803)
        at com.google.mlkit.vision.barcode.internal.zzf.zza(com.google.android.gms:play-services-mlkit-barcode-scanning@@16.1.2:72)
        at com.google.mlkit.vision.barcode.internal.zzf.zzb(com.google.android.gms:play-services-mlkit-barcode-scanning@@16.1.2:83)
        at com.google.mlkit.vision.barcode.internal.zzf.run(com.google.android.gms:play-services-mlkit-barcode-scanning@@16.1.2:143)
        at com.google.mlkit.vision.common.internal.MobileVisionBase.zza(com.google.mlkit:vision-common@@16.1.0:23)
        at com.google.mlkit.vision.common.internal.zzc.call(com.google.mlkit:vision-common@@16.1.0)
        at com.google.mlkit.common.sdkinternal.ModelResource.zza(com.google.mlkit:common@@17.0.0:29)
        ... 8 more
I/Status: In complete listener on 1602190069614
    In failure listener on 1602190069614 because: com.google.mlkit.common.MlKitException: Internal error has occurred when executing ML Kit tasks
I/Failure: com.google.mlkit.common.MlKitException: Internal error has occurred when executing ML Kit tasks
W/System.err: com.google.mlkit.common.MlKitException: Internal error has occurred when executing ML Kit tasks
        at com.google.mlkit.common.sdkinternal.ModelResource.zza(com.google.mlkit:common@@17.0.0:32)
        at com.google.mlkit.common.sdkinternal.zzl.run(com.google.mlkit:common@@17.0.0)
        at com.google.mlkit.common.sdkinternal.zzp.run(com.google.mlkit:common@@17.0.0:3)
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zzd(com.google.mlkit:common@@17.0.0:24)
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zza(com.google.mlkit:common@@17.0.0:30)
        at com.google.mlkit.common.sdkinternal.zzh.run(com.google.mlkit:common@@17.0.0)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
        at java.lang.Thread.run(Thread.java:762)
W/System.err: Caused by: java.lang.IllegalStateException: Image is already closed
        at android.media.Image.throwISEIfImageIsInvalid(Image.java:68)
        at android.media.ImageReader$SurfaceImage$SurfacePlane.getBuffer(ImageReader.java:803)
        at com.google.mlkit.vision.barcode.internal.zzf.zza(com.google.android.gms:play-services-mlkit-barcode-scanning@@16.1.2:72)
        at com.google.mlkit.vision.barcode.internal.zzf.zzb(com.google.android.gms:play-services-mlkit-barcode-scanning@@16.1.2:83)
        at com.google.mlkit.vision.barcode.internal.zzf.run(com.google.android.gms:play-services-mlkit-barcode-scanning@@16.1.2:143)
        at com.google.mlkit.vision.common.internal.MobileVisionBase.zza(com.google.mlkit:vision-common@@16.1.0:23)
        at com.google.mlkit.vision.common.internal.zzc.call(com.google.mlkit:vision-common@@16.1.0)
        at com.google.mlkit.common.sdkinternal.ModelResource.zza(com.google.mlkit:common@@17.0.0:29)
        ... 8 more
I/Status: In complete listener on 1602190069615

【问题讨论】：

图像已经关闭的异常是从哪里抛出的？从 BarcodeScanner 内部还是其他地方？它是在 addOnCompleteListener 中的代码运行之前还是之后发生的？
我在我的帖子中添加了一些日志记录。如您所见，分析器在（系统毫秒）时间 1602190069609 进入（Log = In setAnalyzer on 1602190069609），然后进程进入失败侦听器（Log = In failure listener on 1602190069612），然后进入完成的侦听器（Log = 在 1602190069614 上的完整监听器中）。我不知道在同一时刻（1602190069614）也调用了失败侦听器是否很奇怪。
为什么 //imageProxy.close() 在你的 onCompleteListener 中被注释掉了？这可能是造成这种情况的原因。另外，我不熟悉 Kotlin 语法，但看起来您设置三个侦听器的方式可能是错误的。至少在 Java 中，我希望看到在 addOnCompleteListener 中创建 OnCompleteListener 对象，类似于您在 addOnFailureListener 中的内容，但没有其他侦听器。查看我遇到的类似问题的更多详细信息here
@topher217 ImageProxy 已关闭，因为我尝试了如果我将其注释掉会产生什么影响（它没有改变任何东西），然后当我在此论坛上更新我的代码后忘记取消注释它添加一些注释行。听众的语法对我来说似乎是正确的。这是 Kotlin 语法。要进行比较，您可以随时在此处查看link。
根据topher217 的评论，我用Java（而不是Kotlin）重写了我的代码。我再次按照教程进行操作，并且成功了！基于 Java 代码，我调整了我的 Kotlin 代码，现在它也可以工作了。主要的变化是在我的 layout_main.xml 中用“androidx.camera.view.PreviewView”替换了“TextureView”（它提供了我的相机的输入），我猜 setAnalyzer 块也有问题。还是谢谢！

标签： android barcode-scanner illegalstateexception android-camerax google-mlkit

【解决方案1】：

只是为了帮助其他人，我在这里发布我的最新（工作）代码

Build.gradle

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.2"

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    defaultConfig {
        applicationId "be.lapit.qrcodescanner"
        minSdkVersion 21
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation 'androidx.core:core-ktx:1.3.2'
    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'

    // ML Kit Barcode scanner
    implementation 'com.google.mlkit:barcode-scanning:16.0.3'
    implementation 'com.google.android.gms:play-services-mlkit-barcode-scanning:16.1.2'

    // CameraX
    def camerax_version = "1.0.0-alpha10"
    // The following line is optional, as the core library is included indirectly by camera-camera2
    implementation "androidx.camera:camera-core:${camerax_version}"
    implementation "androidx.camera:camera-camera2:${camerax_version}"
    // If you want to additionally use the CameraX Lifecycle library
    implementation "androidx.camera:camera-lifecycle:${camerax_version}"
    // If you want to additionally use the CameraX View class
    implementation "androidx.camera:camera-view:1.0.0-alpha17"
    // If you want to additionally use the CameraX Extensions library
    implementation "androidx.camera:camera-extensions:1.0.0-alpha17"

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:id="@+id/linearLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">


        <Button
            android:id="@+id/btnGallery"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Get picture"></Button>

        <FrameLayout
            android:id="@+id/container"
            android:layout_width="450px"
            android:layout_height="450px">
            <androidx.camera.view.PreviewView
                android:id="@+id/preview_view"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@color/colorRed"
                android:layout_gravity="center" />
        </FrameLayout>


    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.kt

package be.lapit.qrcodescanner

import android.Manifest
import android.content.Intent
import android.content.pm.PackageManager
import android.os.Bundle
import android.util.Log
import android.util.Size
import android.view.TextureView
import android.widget.Button
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.camera.core.*
import androidx.camera.core.impl.ImageAnalysisConfig
import androidx.camera.core.impl.PreviewConfig
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.view.PreviewView
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import androidx.lifecycle.LifecycleOwner
import com.google.android.gms.tasks.OnFailureListener
import com.google.common.util.concurrent.ListenableFuture
import com.google.mlkit.vision.barcode.Barcode
import com.google.mlkit.vision.barcode.BarcodeScannerOptions
import com.google.mlkit.vision.barcode.BarcodeScanning
import com.google.mlkit.vision.common.InputImage
import java.time.Instant
import java.time.format.DateTimeFormatter
import kotlin.system.measureTimeMillis


class MainActivity : AppCompatActivity() {

    // PLA: Variable needed to check if user has granted camera permission
    companion object {
        private const val REQUEST_CAMERA_PERMISSION = 10
    }

    private lateinit var cameraProviderFuture : ListenableFuture<ProcessCameraProvider>
    private lateinit var previewView: PreviewView

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

        previewView = findViewById(R.id.preview_view)

        // Request camera permissions
        if (isCameraPermissionGranted()) {
            previewView.post { startCamera() }
        } else {
            ActivityCompat.requestPermissions(
                this,
                arrayOf(Manifest.permission.CAMERA),
                REQUEST_CAMERA_PERMISSION
            )
        }


    }

    private fun startCamera() {
        // -----------------------
        // Setup use case Preview
        // -----------------------
        cameraProviderFuture = ProcessCameraProvider.getInstance(this)

        cameraProviderFuture.addListener(Runnable {
            val cameraProvider = cameraProviderFuture.get()
            bindPreview(cameraProvider)
        }, ContextCompat.getMainExecutor(this))

    }


    fun bindPreview(cameraProvider : ProcessCameraProvider) {
        var preview : Preview = Preview.Builder()
            .build()

        var cameraSelector : CameraSelector = CameraSelector.Builder()
            .requireLensFacing(CameraSelector.LENS_FACING_FRONT)
            .build()

        var previewView: PreviewView = findViewById(R.id.preview_view)
        preview.setSurfaceProvider(previewView.surfaceProvider)

        val imageAnalysis = ImageAnalysis.Builder()
            .setTargetResolution(Size(1280, 720))
            .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
            .build()

        // Define options for barcode scanner
        val options = BarcodeScannerOptions.Builder()
            .setBarcodeFormats(
                Barcode.FORMAT_QR_CODE,
                Barcode.FORMAT_AZTEC)
            .build()

        imageAnalysis.setAnalyzer(ContextCompat.getMainExecutor(this), ImageAnalysis.Analyzer { imageProxy ->
            val rotationDegrees = imageProxy.imageInfo.rotationDegrees

            // Initiate barcode scanner
            val scanner = BarcodeScanning.getClient(options)

            // insert your code here.
            @androidx.camera.core.ExperimentalGetImage
            val mediaImage = imageProxy.image

            @androidx.camera.core.ExperimentalGetImage
            if (mediaImage != null) {
                val image = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)

                // Pass image to an ML Kit Vision API
                @androidx.camera.core.ExperimentalGetImage
                val result = scanner.process(image)
                    .addOnSuccessListener { barcodes ->
                        // Task completed successfully
                        Log.i("Status", "In success listener")
                        for (barcode in barcodes) {
                            val bounds = barcode.boundingBox
                            val corners = barcode.cornerPoints

                            val rawValue = barcode.rawValue
                            Log.i("QR code", rawValue.toString())

                            val valueType = barcode.valueType
                            // See API reference for complete list of supported types
                            when (valueType) {
                                Barcode.TYPE_WIFI -> {
                                    val ssid = barcode.wifi!!.ssid
                                    val password = barcode.wifi!!.password
                                    val type = barcode.wifi!!.encryptionType
                                }
                                Barcode.TYPE_URL -> {
                                    val title = barcode.url!!.title
                                    val url = barcode.url!!.url
                                }
                            }
                        }
                    }
                    .addOnFailureListener {
                        // Task failed with an exception
                        Log.i("Status", "In failure listener")
                    }
                    .addOnCompleteListener{
                        // Task failed with an exception
                        Log.i("Status", "In on complete listener")
                        imageProxy.close()
                    }
            }

        })

        cameraProvider.bindToLifecycle(this as LifecycleOwner, cameraSelector, imageAnalysis, preview)
    }


    private fun isCameraPermissionGranted(): Boolean {
        val selfPermission = ContextCompat.checkSelfPermission(
            baseContext,
            Manifest.permission.CAMERA
        )
        return selfPermission == PackageManager.PERMISSION_GRANTED
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<String>,
        grantResults: IntArray
    ) {
        if (requestCode == REQUEST_CAMERA_PERMISSION) {
            if (isCameraPermissionGranted()) {
                previewView.post { startCamera() }
            } else {
                Toast.makeText(this, "Camera permission is required.", Toast.LENGTH_SHORT).show()
                finish()
            }
        }
    }
}

【讨论】：

【解决方案2】：

我不能 100% 确定这是否相关，但您可以尝试将您的 CameraX 依赖项更新到最新版本吗？你的是 1.0.0-alpha04，而最新的是 1.0.0-beta10。 https://developer.android.com/jetpack/androidx/releases/camera

对于您正在使用的 API - setImageReaderMode(ImageAnalysis.ImageReaderMode.ACQUIRE_LATEST_IMAGE)，我无法在 CameraX 开发网站上找到它：https://developer.android.com/reference/androidx/camera/core/ImageAnalysis

至于 .setImageQueueDepth(1)，似乎不适用于默认策略：https://developer.android.com/reference/androidx/camera/core/ImageAnalysis.Builder#setImageQueueDepth(int)

另一个小建议：您目前在每个帧中创建一个新的 BarcodeDetector，这可能会很慢。在分析器之外创建一次并重用相同的实例可能会更好。

希望一些观点有所帮助:)

【讨论】：

你好 Steven，我能够让它工作（参见我在上一篇文章中的最新评论）。我用 1.0.0-alpha04 和 1.0.0-alpha10 对其进行了测试，两者都有效。我还删除了 setImageReaderMode 和 setImageQueueDepth （它们没用）。感谢您将条形码检测器的创建放在框架之外的提示。我提高了性能。谢谢！