Android zxing 解析二维码，生成二维码极简demo

zxing 官方的代码很多，看起来很费劲，此demo只抽取了有用的部分，实现了相机预览解码，解析本地二维码，生成二维码三个功能。

简化后的结构如下：

废话少说直接上代码：

BaseDecodeHandler：

package com.song.zxing.decode;

import android.graphics.Bitmap;
import android.os.Bundle;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.PlanarYUVLuminanceSource;

import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.Map;

/**
 * Created by Administrator on 2015/12/16.
 */
public class BaseDecodeHandler {
    MultiFormatReader multiFormatReader;

    public BaseDecodeHandler() {
        initReader();
    }

    private void initReader() {
        multiFormatReader = new MultiFormatReader();
        Map<DecodeHintType, Object> hints = new EnumMap<DecodeHintType, Object>(DecodeHintType.class);
        Collection<BarcodeFormat> decodeFormats = new ArrayList<BarcodeFormat>();
        decodeFormats.addAll(EnumSet.of(BarcodeFormat.QR_CODE));
        decodeFormats.addAll(EnumSet.of(BarcodeFormat.CODABAR));
        hints.put(DecodeHintType.POSSIBLE_FORMATS, decodeFormats);
        multiFormatReader.setHints(hints);
    }

    public Bundle getThumbData(PlanarYUVLuminanceSource source) {
        Bundle bundle = new Bundle();
        int[] pixels = source.renderThumbnail();
        int width = source.getThumbnailWidth();
        int height = source.getThumbnailHeight();
        Bitmap bitmap = Bitmap.createBitmap(pixels, 0, width, width, height, Bitmap.Config.ARGB_8888);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 50, out);
        bundle.putByteArray("data", out.toByteArray());
        return bundle;
    }
}

　　

PreviewDecodeHandler：

package com.song.zxing.decode;

import android.graphics.Rect;
import android.hardware.Camera;
import android.os.Handler;
import android.os.Message;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.PlanarYUVLuminanceSource;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;
import com.song.zxing.util.Constant;

/**
 * Created by Administrator on 2015/12/16.
 */
public class PreviewDecodeHandler extends BaseDecodeHandler implements Camera.PreviewCallback {
    private Rect rect;
    private boolean running;
    private Handler handler;

    public PreviewDecodeHandler(Rect rect, Handler handler) {
        this.rect = rect;
        this.handler = handler;
    }

    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        if (running) {
            return;
        }
        decode(data, camera);
    }

    private void decode(byte[] data, Camera camera) {
        Camera.Size size = camera.getParameters().getPreviewSize();
        running = true;
        // 这里需要将获取的data翻转一下，因为相机默认拿的的横屏的数据
        byte[] rotatedData = new byte[data.length];
        for (int y = 0; y < size.height; y++) {
            for (int x = 0; x < size.width; x++)
                rotatedData[x * size.height + size.height - y - 1] = data[x + y * size.width];
        }

        // 宽高也要调整
        int tmp = size.width;
        size.width = size.height;
        size.height = tmp;

        Result rawResult = null;
        // Go ahead and assume it's YUV rather than die.
        PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource(rotatedData, size.width, size.height, rect.left, rect.top, rect.width(), rect.height(), false);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
        try {
            rawResult = multiFormatReader.decodeWithState(bitmap);
        } catch (ReaderException re) {
            // continue
        } finally {
            multiFormatReader.reset();
        }
        if (rawResult != null) {
            if (handler != null) {
                Message msg = Message.obtain(handler, Constant.VALUE_DECODE_SUCCESS, rawResult.getText());
//                msg.setData(getThumbData(source)); // 去掉注释可以拿到最终图片
                msg.sendToTarget();
            }
        }
        running = false;
    }
}

　　

CameraView:

package com.song.zxing.ui;

import android.app.Activity;
import android.content.Context;
import android.hardware.Camera;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import com.song.zxing.App;
import com.song.zxing.util.AutoFocusManager;

import java.util.List;

/**
 * use decrypted Api mCamera
 */
public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
    private Camera mCamera;
    private SurfaceHolder mHolder;
    private AutoFocusManager autoFocusManager;

    public CameraView(Context context) {
        super(context);
        init();
    }

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

    public CameraView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        mHolder = getHolder();
        mHolder.addCallback(this);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        try {
            mCamera = Camera.open();
        } catch (Exception e) {
            e.printStackTrace();
            App.toast("相机打开失败");
            ((Activity) getContext()).finish();
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        if (mHolder.getSurface() == null) {
            return;
        }
        try {
            mCamera.setDisplayOrientation(90);
            mCamera.setPreviewDisplay(mHolder);
            setPreviewSize();
            start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

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

    private void setPreviewSize() {
        if (mCamera == null) return;
        Camera.Parameters parameters = mCamera.getParameters();
        Camera.Size cameraSize = getOptimalPreviewSize(parameters.getSupportedPreviewSizes(), App.getScreenHeight(), App.getScreenWidth());
        Camera.Size pictureSize = getOptimalPreviewSize(parameters.getSupportedPictureSizes(), App.getScreenHeight(), App.getScreenWidth());
        parameters.setPreviewSize(cameraSize.width, cameraSize.height);
        parameters.setPictureSize(pictureSize.width, pictureSize.height);
        mCamera.setParameters(parameters);
    }

    private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.1;
        double targetRatio = (double) w / h;
        if (sizes == null) return null;

        Camera.Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;

        for (Camera.Size size : sizes) {
            double ratio = (double) size.width / size.height;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
            if (Math.abs(size.height - h) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - h);
            }
        }

        // Cannot find the one match the aspect ratio, ignore the requirement
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Camera.Size size : sizes) {
                if (Math.abs(size.height - h) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - h);
                }
            }
        }
        return optimalSize;
    }

    public void capture(Camera.PictureCallback callback) {
        if (mCamera != null)
            mCamera.takePicture(null, null, callback);
    }

    public void stopPreview() {
        if (mCamera != null)
            mCamera.stopPreview();
    }

    public void setPreviewCallback(Camera.PreviewCallback callback) {
        if (mCamera != null) {
            mCamera.setPreviewCallback(callback);
        }
    }

    private void start() {
        if (mCamera != null) {
            mCamera.startPreview();
            autoFocusManager = new AutoFocusManager(mCamera);
            if (listener != null) {
                listener.initSuccess();
            }
        }
    }

    public void release() {
        if (mCamera != null) {
            mCamera.stopPreview();
            mCamera.setPreviewCallback(null);
            mCamera.release();
            mCamera = null;
        }
    }

    InitListener listener;

    public void setInitListener(InitListener listener) {
        this.listener = listener;
    }

    public interface InitListener {
        void initSuccess();
    }
}

　　

ScreenOverlay:

package com.song.zxing.ui;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;

import com.song.zxing.App;
import com.song.zxing.R;

/**
 * Created by Administrator on 2015/11/4.
 */
public class ScreenOverlay extends View {
    private RectF rectF;
    private Paint paint;
    private Bitmap rectBitmap;
    private Bitmap lineBitmap;
    private int lineOffset = 2;
    private int rectBitmapWidth;
    private int rectBitmapHeight;

    public ScreenOverlay(Context context) {
        super(context);
    }

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

    public ScreenOverlay(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    private void initPoint() {
        rectBitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.qr_capture);
        lineBitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.qr_scan_line);
        int mScreenWidth = App.getScreenWidth();
        int mScreenHeight = App.getScreenHeight();
        rectBitmapWidth = rectBitmap.getWidth();
        rectBitmapHeight = rectBitmap.getHeight();
        float left = (mScreenWidth - rectBitmapWidth) / 2;
        float top = (mScreenHeight - rectBitmapHeight - 20) / 2;
        float right = left + rectBitmapWidth;
        float bottom = top + rectBitmapHeight;
        rectF = new RectF(left, top, right, bottom);

        paint = new Paint();
        paint.setColor(Color.parseColor("#60000000"));
    }

    @Override
    public void draw(Canvas canvas) {
        super.draw(canvas);
        canvas.drawRect(0, 0, App.getScreenWidth(), rectF.top, paint);
        canvas.drawRect(0, rectF.top, rectF.left, rectF.bottom, paint);
        canvas.drawRect(0, rectF.bottom, App.getScreenWidth(), App.getScreenHeight(), paint);
        canvas.drawRect(rectF.right, rectF.top, App.getScreenWidth(), rectF.bottom, paint);
        canvas.drawBitmap(rectBitmap, rectF.left, rectF.top, paint);
        canvas.drawBitmap(lineBitmap, null, getDstRect(rectF, lineOffset), paint);
        lineOffset = lineOffset >= rectBitmapHeight - 10 ? 10 : lineOffset + 2;
        invalidate();
    }

    private Rect getDstRect(RectF rectF, int offset) {
        Rect rect = new Rect();
        rect.left = (int) rectF.left;
        rect.top = (int) rectF.top + offset;
        rect.bottom = rect.top + App.dp2Px(2);
        rect.right = (int) (rectF.left + rectBitmapWidth);
        return rect;
    }

    public RectF getPreviewRectF() {
        return rectF;
    }

    public Rect getPreviewRect() {
        Rect rect = new Rect();
        rectF.round(rect);
        return rect;
    }

    public void stopScan() {

    }
}

　　

TestActivity:

package com.song.zxing;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;

import com.song.zxing.decode.BitmapDecodeHandler;
import com.song.zxing.decode.PreviewDecodeHandler;
import com.song.zxing.encode.QRCreator;
import com.song.zxing.ui.CameraView;
import com.song.zxing.ui.ScreenOverlay;
import com.song.zxing.util.BitmapUtil;
import com.song.zxing.util.Constant;

/**
 * Created by Administrator on 2015/12/16.
 */
public class TestActivity extends Activity {
    CameraView cameraView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test);
        cameraView = (CameraView) findViewById(R.id.cameraView);
        final ScreenOverlay overlay = (ScreenOverlay) findViewById(R.id.overlay);
        cameraView.setInitListener(new CameraView.InitListener() {
            @Override
            public void initSuccess() {
                cameraView.setPreviewCallback(new PreviewDecodeHandler(overlay.getPreviewRect(), handler));
            }
        });
        findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new BitmapDecodeHandler().start(BitmapFactory.decodeFile(Environment.getExternalStorageDirectory() + "/fuck.png"), handler);
            }
        });
        findViewById(R.id.btn_createQr).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Bitmap bitmap = new QRCreator().createQRImage("this is a test string", 250, 250, BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher));
//                Bitmap bitmap = new QRCreator().createQRImage("this is a test string", 250, 250, null);
                BitmapUtil.write2File(bitmap, Environment.getExternalStorageDirectory() + "/fuck.png");
                App.toast("create complete!");
            }
        });
    }

    Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == Constant.VALUE_DECODE_SUCCESS) {
                App.toast((String) msg.obj);
                cameraView.setPreviewCallback(null);// stop decode
            } else if (msg.what == Constant.VALUE_DECODE_FAIL) {
                App.toast("decode Fail");
            }
        }
    };

    @Override
    protected void onDestroy() {
        super.onDestroy();
        cameraView.release();
        cameraView = null;
    }
}

　　详细代码见：http://download.csdn.net/detail/hesongxing/9365515

注：工程代码使用Android studio 开发。