Android掃描二維碼

1.效果圖：

2.引用公共庫:builder.radle，在app目錄下

implementation 'com.google.android.gms:play-services-maps:17.0.0'
implementation 'com.google.android.gms:play-services-vision:19.0.0'
implementation 'com.google.android.gms:auth-api-impl:11.6.0'

3.清單文件，拍照權限申請 

<uses-permission android:name="android.permission.CAMERA" />

4.主界面：

package com.example.administrator.testz;


import android.Manifest;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.net.Uri;
import android.os.Bundle;
import android.os.PersistableBundle;
import android.os.Vibrator;
import android.util.Log;
import android.util.SparseArray;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.TextView;

import com.google.android.gms.vision.CameraSource;
import com.google.android.gms.vision.Detector;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;

import java.io.IOException;
import java.util.ArrayList;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;


public class MainActivity extends AppCompatActivity {

    SurfaceView surfaceView;
    CameraSource cameraSource;
    TextView qrCodeText;
    BarcodeDetector barcodeDetector;
    public static ArrayList<String> scannList;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        surfaceView = (SurfaceView) findViewById(R.id.qrView);
        qrCodeText = (TextView) findViewById(R.id.tv);
        scannList = new ArrayList<>();
        barcodeDetector = new BarcodeDetector.Builder(this)
                .setBarcodeFormats(Barcode.QR_CODE)
                .build();
        cameraSource = new CameraSource.Builder(this, barcodeDetector)
                .setRequestedPreviewSize(640, 480)
                .setAutoFocusEnabled(true)
                .build();
        surfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {
                if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                    return;
                }
                try {
                    cameraSource.start(holder);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

            }

            @Override
            public void surfaceDestroyed(SurfaceHolder holder) {
                cameraSource.stop();
            }
        });


        barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
            @Override
            public void release() {
            }

            @Override
            public void receiveDetections(Detector.Detections<Barcode> detections) {
                final SparseArray<Barcode> qrCode = detections.getDetectedItems();

                if (qrCode.size() != 0) {
                    qrCodeText.post(new Runnable() {
                        @Override
                        public void run() {
                            qrCodeText.setText(qrCode.valueAt(0).displayValue);
                            addInList(qrCode.valueAt(0).displayValue);
                        }
                    });
                }
            }
        });

    }

    private void addInList(String scannResult) {
        if (scannList.isEmpty()) {
            scannList.add(scannResult);
        } else {
            String a = scannList.get(scannList.size() - 1);
            if (!a.equals(scannResult)) {
                scannList.add(scannResult);
            }
        }
        for (String s : scannList) {
            Log.e("s", "onCreate: " + s);
        }
        Log.e("size", "addInList: " + scannList.size());

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

    }
}

5.佈局頁面：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.administrator.testz.MainActivity">


    <SurfaceView
        android:id="@+id/qrView"
        android:layout_width="300dp"
        android:layout_height="300dp"
        android:layout_marginStart="32dp"
        android:layout_marginLeft="32dp"
        android:layout_marginEnd="32dp"
        android:layout_marginRight="32dp"
        android:orientation="vertical" />

    <TextView
        android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:text="TextView"
        android:textSize="30sp" />


</RelativeLayout>

end