Android使用ZXing实现二维码扫描功能（总结）

使用方式也很简单，首先在gradle中添加依赖

compile 'com.journeyapps:zxing-android-embedded:3.5.0'

1、自定义布局文件activity_custom_capture.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:gravity="center_horizontal"
    android:orientation="vertical">

    <com.journeyapps.barcodescanner.DecoratedBarcodeView
        android:id="@+id/Activity_Custom_Capture_customBDV"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:zxing_preview_scaling_strategy="fitXY" />

</LinearLayout>

2、自定义CustomCaptureActivity的代码如下：

package com.deepreality.zxingdemo;

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;
import android.view.Window;

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

public class CustomCaptureActivity extends AppCompatActivity {

    private CaptureManager capture;
    private DecoratedBarcodeView barcodeScannerView;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_custom_capture);// 自定义布局

        barcodeScannerView = (DecoratedBarcodeView) findViewById(R.id.Activity_Custom_Capture_customBDV);

        capture = new CaptureManager(this, barcodeScannerView);
        capture.initializeFromIntent(getIntent(), savedInstanceState);
        capture.decode();
    }

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

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

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

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        capture.onSaveInstanceState(outState);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
        capture.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }

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

3、在MainActivity中调用

package com.deepreality.zxingdemo;

import android.content.Intent;
import android.graphics.Bitmap;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.integration.android.IntentIntegrator;
import com.google.zxing.integration.android.IntentResult;
import com.journeyapps.barcodescanner.BarcodeEncoder;

import javax.xml.transform.Templates;

public class MainActivity extends AppCompatActivity {

    private Button btnMatch;
    private TextView tvResult;

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

        btnMatch = findViewById(R.id.main_btnMatch);
        tvResult = findViewById(R.id.main_tvResult);

        btnMatch.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startScanEcode();
            }
        });
    }

    /**
     * 将str内容生成二维码图片
     * @param str
     * @return
     */
    private Bitmap encodeAsBitmap(String str){
        Bitmap bitmap = null;
        BitMatrix result = null;
        MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
        try {
            result = multiFormatWriter.encode(str, BarcodeFormat.QR_CODE, 200, 200);
            // 使用 ZXing Android Embedded 要写的代码
            BarcodeEncoder barcodeEncoder = new BarcodeEncoder();
            bitmap = barcodeEncoder.createBitmap(result);
        } catch (WriterException e){
            e.printStackTrace();
        } catch (IllegalArgumentException iae){
            return null;
        }
        return bitmap;
    }

    /**
     * 开始扫码二维码
     */
    private void startScanEcode() {
        new IntentIntegrator(this)
                .setCaptureActivity(CustomCaptureActivity.class)//打开自定义的View
                .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
                .setBarcodeImageEnabled(true)// 扫完码之后生成二维码的图片
                .initiateScan();// 初始化扫码
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
        if(result != null) {
            if(result.getContents() == null) {
                Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(this, "Scanned: " + result.getContents(), Toast.LENGTH_LONG).show();
            }
        } else {
            super.onActivityResult(requestCode, resultCode, data);
        }
    }
}