Android Studio+zxing二维码扫描的实现

前言

项目需要，只有单纯的二维码扫描识别，没有二维码的生成。
网上有很多教程，所以有借鉴其他人的代码，只是单纯记录一下~~

导入依赖

在build.gradle里面加入：

implementation 'com.journeyapps:zxing-android-embedded:3.6.0'

功能实现

自带扫描框

首先在布局文件中添加按钮，然后对按钮添加点击事件

btBarcode.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new IntentIntegrator(getActivity())
                        .setDesiredBarcodeFormats(IntentIntegrator.ALL_CODE_TYPES)// 扫码的类型,可选：一维码，二维码，一/二维码
                        .setPrompt("请对准二维码")// 设置提示语
                        .setCameraId(0)// 选择摄像头,可使用前置或者后置
                        .setBeepEnabled(true)// 是否开启声音,扫完码之后会"哔"的一声
                        .setCaptureActivity(CaptureActivity.class)//默认扫码界面（横屏）
                        .initiateScan();// 初始化扫码
            }
        });

然后在MainActivity.java里面重写onActivityResult函数，处理二维码扫描结果

@Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        /**
         * 处理二维码扫描结果
         */
        //扫码结果
        IntentResult intentResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
        if (intentResult != null) {
            if (intentResult.getContents() == null) {
                //扫码失败
                Toast.makeText(MainActivity.this, "扫码失败" , Toast.LENGTH_LONG).show();
            } else {
                String result = intentResult.getContents();//返回值
                Toast.makeText(MainActivity.this, "扫码结果：" + result, Toast.LENGTH_LONG).show();
            }
        }
    }

然后就可以简单实现二维码扫描并返回结果了。
但是自带的扫描框是横向的，而且没有边框之类的，可以自定义一个

自定义扫描框

添加一个CustomZxingView用于绘制自定义的扫描框

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Rect;
import android.graphics.Shader;
import android.util.AttributeSet;

import com.google.zxing.ResultPoint;
import com.journeyapps.barcodescanner.ViewfinderView;

import java.util.ArrayList;
import java.util.List;

public class CustomZxingView extends ViewfinderView {

    public int laserLinePosition = 0;
    public float[] position = new float[]{0f, 0.5f, 1f};
    public int[] colors = new int[]{0xff0699e6, 0xff0699e6, 0xff0699e6};
    public LinearGradient linearGradient;

    public CustomZxingView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * 重写draw方法绘制自己的扫描框
     *
     * @param canvas
     */
    @Override
    public void onDraw(Canvas canvas) {
        refreshSizes();
        if (framingRect == null || previewFramingRect == null) {
            return;
        }

        Rect frame = framingRect;
        Rect previewFrame = previewFramingRect;

        int width = canvas.getWidth();
        int height = canvas.getHeight();
        //绘制4个角

        paint.setColor(Color.parseColor("#139D57"));//定义画笔的颜色
        canvas.drawRect(frame.left, frame.top, frame.left + 100, frame.top + 10, paint);
        canvas.drawRect(frame.left, frame.top, frame.left + 10, frame.top + 100, paint);

        canvas.drawRect(frame.right - 100, frame.top, frame.right, frame.top + 10, paint);
        canvas.drawRect(frame.right - 10, frame.top, frame.right, frame.top + 100, paint);

        canvas.drawRect(frame.left, frame.bottom - 10, frame.left + 100, frame.bottom, paint);
        canvas.drawRect(frame.left, frame.bottom - 100, frame.left + 10, frame.bottom, paint);

        canvas.drawRect(frame.right - 100, frame.bottom - 10, frame.right, frame.bottom, paint);
        canvas.drawRect(frame.right - 10, frame.bottom - 100, frame.right, frame.bottom, paint);
        // Draw the exterior (i.e. outside the framing rect) darkened
        paint.setColor(resultBitmap != null ? resultColor : maskColor);
        canvas.drawRect(0, 0, width, frame.top, paint);
        canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
        canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, paint);
        canvas.drawRect(0, frame.bottom + 1, width, height, paint);

        if (resultBitmap != null) {
            // Draw the opaque result bitmap over the scanning rectangle
            paint.setAlpha(CURRENT_POINT_OPACITY);
            canvas.drawBitmap(resultBitmap, null, frame, paint);
        } else {
            int middle = frame.height() / 2 + frame.top;
            laserLinePosition = laserLinePosition + 5;
            if (laserLinePosition > frame.height()) {
                laserLinePosition = 0;
            }
            linearGradient = new LinearGradient(frame.left + 1, frame.top + laserLinePosition, frame.right - 1, frame.top + 10 + laserLinePosition, colors, position, Shader.TileMode.CLAMP);
            // Draw a red "laser scanner" line through the middle to show decoding is active
            paint.setShader(linearGradient);
            //绘制扫描线
            canvas.drawRect(frame.left + 1, frame.top + laserLinePosition, frame.right - 1, frame.top + 10 + laserLinePosition, paint);
            paint.setShader(null);
            float scaleX = frame.width() / (float) previewFrame.width();
            float scaleY = frame.height() / (float) previewFrame.height();

            List<ResultPoint> currentPossible = possibleResultPoints;
            List<ResultPoint> currentLast = lastPossibleResultPoints;
            int frameLeft = frame.left;
            int frameTop = frame.top;
            if (currentPossible.isEmpty()) {
                lastPossibleResultPoints = null;
            } else {
                possibleResultPoints = new ArrayList<>(5);
                lastPossibleResultPoints = currentPossible;
                paint.setAlpha(CURRENT_POINT_OPACITY);
                paint.setColor(resultPointColor);
                for (ResultPoint point : currentPossible) {
                    canvas.drawCircle(frameLeft + (int) (point.getX() * scaleX),
                            frameTop + (int) (point.getY() * scaleY),
                            POINT_SIZE, paint);
                }
            }
            if (currentLast != null) {
                paint.setAlpha(CURRENT_POINT_OPACITY / 2);
                paint.setColor(resultPointColor);
                float radius = POINT_SIZE / 2.0f;
                for (ResultPoint point : currentLast) {
                    canvas.drawCircle(frameLeft + (int) (point.getX() * scaleX),
                            frameTop + (int) (point.getY() * scaleY),
                            radius, paint);
                }
            }
            postInvalidateDelayed(16,
                    frame.left,
                    frame.top,
                    frame.right,
                    frame.bottom);
        }
    }
}

QrCodeActivity.java

import android.os.Bundle;
import android.os.PersistableBundle;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;

import com.journeyapps.barcodescanner.CaptureManager;
import com.journeyapps.barcodescanner.DecoratedBarcodeView;

import cn.edu.whu.bdmobile.R;

public class QrCodeActivity extends AppCompatActivity implements  DecoratedBarcodeView.TorchListener {

    private DecoratedBarcodeView decoratedBarcodeView;
    private CaptureManager captureManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_qr_code);

        decoratedBarcodeView=this.findViewById(R.id.decoratedBarcodeView);
        //重要代码，初始化捕获
        captureManager = new CaptureManager(this, decoratedBarcodeView);
        captureManager.initializeFromIntent(getIntent(), savedInstanceState);
        captureManager.decode();
        decoratedBarcodeView.setTorchListener(this);
    }

    @Override
    public void onTorchOn() {

    }

    @Override
    public void onTorchOff() {

    }

    @Override
    protected void onPause() {
        super.onPause();
        captureManager.onPause();
    }

    @Override
    protected void onResume() {
        super.onResume();
        captureManager.onResume();
    }

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

    @Override
    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
        super.onSaveInstanceState(outState, outPersistentState);
        captureManager.onSaveInstanceState(outState);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        return decoratedBarcodeView.onKeyDown(keyCode, event) || super.onKeyDown(keyCode, event);
    }
}

新增两个布局文件

activity_qr_code.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical">

    <com.journeyapps.barcodescanner.DecoratedBarcodeView
        android:id="@+id/decoratedBarcodeView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:zxing_framing_rect_height="250dp"
        app:zxing_framing_rect_width="250dp"
        app:zxing_preview_scaling_strategy="fitXY"
        app:zxing_scanner_layout="@layout/layout_zxing"
        app:zxing_use_texture_view="true" />

</LinearLayout>

layout_zxing.xml

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <com.journeyapps.barcodescanner.BarcodeView
        android:id="@+id/zxing_barcode_surface"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:zxing_framing_rect_height="300dp"
        app:zxing_framing_rect_width="300dp" />

    <cn.edu.whu.bdmobile.ui.view.CustomZxingView
        android:id="@+id/zxing_viewfinder_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:zxing_possible_result_points="#139D57"
        app:zxing_result_view="@color/zxing_custom_result_view"
        app:zxing_viewfinder_laser="#fff"
        app:zxing_viewfinder_mask="#60000000" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|center_horizontal"
        android:layout_marginBottom="20dp"
        android:text="请对准二维码开始扫描"
        android:textColor="#fff" />

</merge>

最后修改按钮点击事件，将CaptureActivity换成QrCodeActivity即可

btBarcode.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new IntentIntegrator(getActivity())
                        .setDesiredBarcodeFormats(IntentIntegrator.ALL_CODE_TYPES)// 扫码的类型,可选：一维码，二维码，一/二维码
                        .setPrompt("请对准二维码")// 设置提示语
                        .setCameraId(0)// 选择摄像头,可使用前置或者后置
                        .setBeepEnabled(true)// 是否开启声音,扫完码之后会"哔"的一声
                        //.setCaptureActivity(CaptureActivity.class)//默认扫码界面（横屏）
                        .setCaptureActivity(QrCodeActivity.class)//自定义扫码界面
                        .initiateScan();// 初始化扫码
            }
        });