ZXing 生成二维码，使用Canvas优化二维码显示速度

package com.mytian.lgwstory.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

import com.google.zxing.common.BitArray;
import com.google.zxing.common.BitMatrix;

public class BitMatrixView extends View {
    private BitMatrix mBitMatrix;

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

    public BitMatrixView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public BitMatrixView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    Paint paint;

    {
        paint = new Paint();
        paint.setColor(Color.BLACK);
        paint.setAntiAlias(false);
    }

    public void refresh(BitMatrix mBitMatrix) {
        this.mBitMatrix = mBitMatrix;
        invalidate();
    }

    @Override
    protected void onDraw(final Canvas canvas) {
        super.onDraw(canvas);
        if (null != mBitMatrix) {
            final float[] pts = new float[mBitMatrix.getWidth() * 2];
            final BitArray bitArray = new BitArray(mBitMatrix.getWidth());
            int i;
            canvas.scale(4, 4);
            for (int y = 0; y < mBitMatrix.getHeight(); ++y) {
                i = 0;
                mBitMatrix.getRow(y, bitArray);
                for (int x = 0; x < bitArray.getSize(); ++x) {
                    if (bitArray.get(x)) {
                        pts[i++] = x;
                        pts[i++] = y;
                    }
                }
                if (i > 0) {
                    canvas.drawPoints(pts, 0, i + 1, paint);
                }
            }
            canvas.scale(1, 1);
        }
    }
}

使用

 doPost(subscription = Observable.just(content).subscribeOn(Schedulers.computation()).map
                (new Func1<String, BitMatrix>() {
            @Override
            public BitMatrix call(String content) {
                try {
                    return new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE,
                            mBitCodeImageView.getWidth() / 4, mBitCodeImageView.getHeight() / 4,
                            hints);
                } catch (WriterException e) {
                    return null;
                }
            }
        }).observeOn(AndroidSchedulers.mainThread()).subscribe(new Action1<BitMatrix>() {
            @Override
            public void call(final BitMatrix matrix) {
                mBitCodeImageView.refresh(matrix);
                hideLoading();
                logo.setVisibility(View.VISIBLE);
            }
        }));