google 的ML Kit 二维码识别

google 的ML Kit 还提供了 文字识别、人脸检测、姿势坚持、拍照细分、图像标签、对象检测和跟踪、数字墨水识别等
利用机器学习套件的条形码扫描 API，您可以读取使用大多数标准条形码格式编码的数据。条形码扫描在设备上执行，不需要网络连接
官网地址：https://developers.google.com/ml-kit/vision/barcode-scanning?hl=zh-cn

读取大多数标准格式
线性格式：Codabar、Code 39、Code 93、Code 128、EAN-8、EAN-13、ITF、UPC-A、UPC-E
2D 格式：Aztec、Data Matrix、PDF417、二维码我
我们一起来看看Android的实现吧

导入

def camerax_version = "1.3.0-alpha02"
api "androidx.camera:camera-core:${camerax_version}"
api "androidx.camera:camera-camera2:${camerax_version}"
// If you want to additionally use the CameraX Lifecycle library
api "androidx.camera:camera-lifecycle:${camerax_version}"
// If you want to additionally use the CameraX View class
api "androidx.camera:camera-view:${camerax_version}"
api 'com.google.mlkit:barcode-scanning:17.0.3'

view_preview_view.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <androidx.camera.view.PreviewView
        android:id="@+id/pv_preview"
        android:layout_width="match_parent"
        android:fitsSystemWindows="true"
        android:layout_height="match_parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

CameraPreviewView.kt

import android.annotation.SuppressLint
import android.content.Context
import android.util.AttributeSet
import android.util.Log
import android.util.Size
import android.view.LayoutInflater
import android.widget.FrameLayout
import android.widget.Toast
import androidx.camera.core.*
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.view.PreviewView
import androidx.core.content.ContextCompat
import androidx.lifecycle.*
import com.google.mlkit.vision.barcode.BarcodeScanner
import com.google.mlkit.vision.barcode.BarcodeScannerOptions
import com.google.mlkit.vision.barcode.BarcodeScanning
import com.google.mlkit.vision.barcode.common.Barcode
import com.google.mlkit.vision.common.InputImage
import java.util.concurrent.Executors

/**
 *@author: JayQiu
 *@create: 2023/2/28
 *@description:
 */
class CameraPreviewView @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : FrameLayout(context, attrs, defStyleAttr) {
    private val TAG = CameraPreviewView::class.java.simpleName
    var mPreviewView: PreviewView
    private var mCamera: Camera? = null
    private var mScanner: BarcodeScanner? = null
    private var mCameraAnalysis: ImageAnalysis? = null
    private var mCameraProvider: ProcessCameraProvider? = null

    // 默认使用后置摄像头
    private var cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA//当前相机

    private val mPreview by lazy(LazyThreadSafetyMode.NONE) {
        Preview.Builder().setTargetAspectRatio((AspectRatio.RATIO_4_3)).build()
    }
    private var mOnScannerListener: OnScannerListener? = null

    init {
        inflate(context, R.layout.view_preview_view, this)
        mPreviewView = findViewById(R.id.pv_preview)
        val options = BarcodeScannerOptions.Builder().setBarcodeFormats(
            Barcode.FORMAT_QR_CODE, Barcode.FORMAT_AZTEC
        ).build()
        mScanner = BarcodeScanning.getClient(options)
    }

    fun startCamera(lifecycleOwner: LifecycleOwner) {
        val cameraProviderFuture = ProcessCameraProvider.getInstance(context)
        cameraProviderFuture.addListener({
            mCameraProvider = cameraProviderFuture.get()
            startPreview(lifecycleOwner)
        }, ContextCompat.getMainExecutor(context))
    }

    fun switchCamera(lifecycleOwner: LifecycleOwner) {
        cameraSelector = if (cameraSelector == CameraSelector.DEFAULT_BACK_CAMERA) {
            CameraSelector.DEFAULT_FRONT_CAMERA
        } else {
            CameraSelector.DEFAULT_BACK_CAMERA
        }
        startPreview(lifecycleOwner)
    }

    /**
     * 开启预览
     */
    private fun startPreview(lifecycleOwner: LifecycleOwner) {
        try {
            initCameraAnalysis()
            // 解除相机之前的所有绑定
            mCameraProvider?.unbindAll()
            // 绑定前面用于预览和拍照的UseCase到相机上
            mCamera = mCameraProvider?.bindToLifecycle(lifecycleOwner, cameraSelector, mPreview, mCameraAnalysis)
            // 设置用于预览的view
            mPreview.setSurfaceProvider(mPreviewView.surfaceProvider)

        } catch (exc: Exception) {
            exc.printStackTrace()
            Toast.makeText(context, "相机启动失败，${exc.message}", Toast.LENGTH_SHORT).show()
            mOnScannerListener?.onFailureListener(exc)
        }
    }

    @SuppressLint("UnsafeOptInUsageError")
    private fun initCameraAnalysis() {
        mCameraAnalysis = ImageAnalysis.Builder().setTargetResolution(Size(720, 1280))
            // 仅将最新图像传送到分析仪，并在到达图像时将其丢弃。
            .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST).setImageQueueDepth(1).build()
        mCameraAnalysis?.setAnalyzer(Executors.newSingleThreadExecutor()) { imageProxy ->
            val mediaImage = imageProxy.image
            if (mediaImage != null) {
                val image = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)
                mScanner?.process(image)?.addOnSuccessListener { barcodeList ->
                    val barcode = barcodeList.getOrNull(0)
                    // `rawValue` is the decoded value of the barcode
                    barcode?.rawValue?.let { value ->
                        Log.e(TAG, "==value=====$value")
                        mOnScannerListener?.onSuccessListener(value)
                    }
                }?.addOnFailureListener { e ->
                    mOnScannerListener?.onFailureListener(e)
                }?.addOnCompleteListener {
                    mediaImage.close()
                    imageProxy.close()
                }
            }
        }
    }

    fun addOnScannerListener(onScannerListener: OnScannerListener) {
        this.mOnScannerListener = onScannerListener
    }

    interface OnScannerListener {
        fun onSuccessListener(value: String)
        fun onFailureListener(e: Exception)
    }
}

pv_surface_preview.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <com.threehalf.scanning.CameraPreviewView
        android:layout_width="match_parent"
        android:id="@+id/pv_surface_preview"
        android:layout_height="match_parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>

/**
 *@author: JayQiu
 *@create: 2023/2/28
 *@description:
 */
class ActScanning : AppCompatActivity() {
    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.act_scanning)
       val view= findViewById<CameraPreviewView>(R.id.pv_surface_preview)
        view.startCamera(this)
    }
}