二维码问题（一）

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描述

Android用Zxing生中文二维码现问号。

分析

// 生二维矩阵（编码时指定大小，生图后缩放会模糊致识别失败）
BitMatrix matrix=null;
// 该法不支持生中文二维码
matrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, newsize, newsize);

解决

matrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, newsize, newsize);

改

matrix = new MultiFormatWriter().encode(new String(content.getBytes("UTF-8"), "ISO-8859-1"), BarcodeFormat.QR_CODE, newsize, newsize);

工具类

package widget.zxing.encoding;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.support.v4.content.ContextCompat;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;

/**
 * @decs: 二维码生成
 * @author: xxx
 * @date: 2018/3/30 20:16
 * @version: v 1.0
 */
public final class EncodingHandler {
    private static final int BLACK = 0xff000000;
    private static final int WHITE = 0xffffffff;

    public static Bitmap createQRCode(Context context, String str, int widthAndHeight, int colorRes) throws WriterException {
        Hashtable<EncodeHintType, String> hints = new Hashtable<>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        BitMatrix matrix = null;
        try {
            matrix = new MultiFormatWriter().encode(new String(str.getBytes("UTF-8"), "ISO-8859-1"), BarcodeFormat.QR_CODE, widthAndHeight, widthAndHeight);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        int[] pixels = new int[width * height];
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                if (matrix.get(x, y)) {
                    pixels[y * width + x] = ContextCompat.getColor(context, colorRes);
                }
            }
        }
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

    /**
     * 创二维码
     *
     * @param content   content
     * @param widthPix  widthPix
     * @param heightPix heightPix
     * @param logoBm    logoBm
     * @return 二维码
     */
    public static Bitmap createQRCode(String content, int widthPix, int heightPix, Bitmap logoBm) {
        try {
            if (content == null || "".equals(content)) {
                return null;
            }
            // 配参
            Map<EncodeHintType, Object> hints = new HashMap<>(2);
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            // 容错级别
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
            // 图像数据转换（用矩阵）
            BitMatrix bitMatrix = new QRCodeWriter().encode(content, BarcodeFormat.QR_CODE, widthPix, heightPix, hints);
            int[] pixels = new int[widthPix * heightPix];
            // 下面按二维码算法，逐生二维码图
            // 两for循环是图片横列扫描结果
            for (int y = 0; y < heightPix; y++) {
                for (int x = 0; x < widthPix; x++) {
                    if (bitMatrix.get(x, y)) {
                        pixels[y * widthPix + x] = 0xff000000;
                    } else {
                        pixels[y * widthPix + x] = 0xffffffff;
                    }
                }
            }
            // 生成二维码图格式（用ARGB_8888）
            Bitmap bitmap = Bitmap.createBitmap(widthPix, heightPix, Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, widthPix, 0, 0, widthPix, heightPix);
            if (logoBm != null) {
                bitmap = addLogo(bitmap, logoBm);
            }
            // 须用compress法存Bitmap到文件再读。直返Bitmap无任何压缩，内存消耗巨大。
            return bitmap;
        } catch (WriterException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 二维码中心添Logo图
     */
    private static Bitmap addLogo(Bitmap src, Bitmap logo) {
        if (src == null) {
            return null;
        }
        if (logo == null) {
            return src;
        }
        // 图宽高
        int srcWidth = src.getWidth();
        int srcHeight = src.getHeight();
        int logoWidth = logo.getWidth();
        int logoHeight = logo.getHeight();
        if (srcWidth == 0 || srcHeight == 0) {
            return null;
        }
        if (logoWidth == 0 || logoHeight == 0) {
            return src;
        }
        // Logo大小为二维码整体1/5
        float scaleFactor = srcWidth * 1.0f / 5 / logoWidth;
        Bitmap bitmap = Bitmap.createBitmap(srcWidth, srcHeight, Bitmap.Config.ARGB_8888);
        try {
            Canvas canvas = new Canvas(bitmap);
            canvas.drawBitmap(src, 0, 0, null);
            canvas.scale(scaleFactor, scaleFactor, srcWidth / 2, srcHeight / 2);
            canvas.drawBitmap(logo, (srcWidth - logoWidth) / 2, (srcHeight - logoHeight) / 2, null);
            // FIXME: 2018/8/24 升级28错: 无法将类 Canvas中的方法 save应用到给定类型; 需要: 没有参数 找到: int 原因: 实际参数列表和形式参数列表长度不同
            /*canvas.save(Canvas.ALL_SAVE_FLAG);*/
            canvas.restore();
        } catch (Exception e) {
            bitmap = null;
            e.getStackTrace();
        }
        return bitmap;
    }
}