Android之zxing二维码生成于识别

前言

二维码的应用现在随处可见，最近在弄即时通信软件，所以想添加二维码名片功能，所以就大概搜索了一下，目前二维码识别与生成比较常用的就是google老大的zxing，比较成熟、稳定，推荐使用。

zxing的引入可以采用源码或jar包引入的方式：

1、以源码引入
zxing的源码在github上的地址为：https://github.com/zxing/zxing，只需要下载core下面的源码就行；

2、以jar包方式引入
jar包下载地址为：
http://www.java2s.com/Code/Jar/z/Downloadzxing20corejar.htm，同样只需要下载core.jar就行；

生成二维码的方法很简单，如下面代码所示

// 生成QR图
private void createImage(String content) {
try {
// 把输入的文本转为二维码
            Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");

            BitMatrix bitMatrix = new QRCodeWriter().encode(content,
                    BarcodeFormat.QR_CODE, QR_WIDTH, QR_HEIGHT, hints);

int[] pixels = new int[QR_WIDTH * QR_HEIGHT];
for (int y = 0; y < QR_HEIGHT; y++) {
for (int x = 0; x < QR_WIDTH; x++) {
if (bitMatrix.get(x, y)) {
                        pixels[y * QR_WIDTH + x] = 0xff000000;
                    } else {
                        pixels[y * QR_WIDTH + x] = 0xffffffff;
                    }

                }
            }

            Bitmap bitmap = Bitmap.createBitmap(QR_WIDTH, QR_HEIGHT,
                    Bitmap.Config.ARGB_8888);

            bitmap.setPixels(pixels, 0, QR_WIDTH, 0, 0, QR_WIDTH, QR_HEIGHT);
if (bitmap != null) {
                resultImageView.setImageBitmap(bitmap);
            }

        } catch (WriterException e) {
            e.printStackTrace();
        }
    }

获取二维码图片的内容

获取内容方面比较麻烦，zxing中的LuminanceSource不能直接使用，所以需要写一个扩展的子类，用以专门解析二维码图片中的内容，由于上面生产的图片内容采用的是json数据的格式，所以在获取内容时也需要按json解析一下；
我封装的LuminanceSource的子类为RGBLuminanceSource，代码如下：

package com.lanou.zxingdemo;
import java.io.FileNotFoundException;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

import com.google.zxing.LuminanceSource;

public class RGBLuminanceSource extends LuminanceSource {
private final byte[] luminances;

public RGBLuminanceSource(Bitmap bitmap) {
super(bitmap.getWidth(), bitmap.getHeight());
//得到图片的宽高
int width = bitmap.getWidth();
int height = bitmap.getHeight();
//得到图片的像素
int[] pixels = new int[width * height];
//
        bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
//为了测量纯解码速度,我们将整个图像灰度阵列前面,这是一样的通道
// YUVLuminanceSource在现实应用。
//得到像素大小的字节数
        luminances = new byte[width * height];
//得到图片每点像素颜色
for (int y = 0; y < height; y++) {
int offset = y * width;
for (int x = 0; x < width; x++) {
int pixel = pixels[offset + x];
int r = (pixel >> 16) & 0xff;
int g = (pixel >> 8) & 0xff;
int b = pixel & 0xff;
//当某一点三种颜色值相同时，相应字节对应空间赋值为其值
if (r == g && g == b) {
                    luminances[offset + x] = (byte) r;
                } 
//其它情况字节空间对应赋值为：
else {  
                    luminances[offset + x] = (byte) ((r + g + g + b) >> 2);
                }
            }
        }
    }

public RGBLuminanceSource(String path) throws FileNotFoundException {
this(loadBitmap(path));
    }


@Override
public byte[] getMatrix() {
return luminances;
    }

@Override
public byte[] getRow(int arg0, byte[] arg1) {
if (arg0 < 0 || arg0 >= getHeight()) {
throw new IllegalArgumentException(
"Requested row is outside the image: " + arg0);
        }
int width = getWidth();
if (arg1 == null || arg1.length < width) {
            arg1 = new byte[width];
        }
        System.arraycopy(luminances, arg0 * width, arg1, 0, width);
return arg1;
    }

private static Bitmap loadBitmap(String path) throws FileNotFoundException {
        Bitmap bitmap = BitmapFactory.decodeFile(path);
if (bitmap == null) {
throw new FileNotFoundException("Couldn't open " + path);
        }
return bitmap;
    }
}

解析二维码内容的方法，代码如下：

// 解析QR图片
private void scanningImage() {
        BitmapDrawable drawable = (BitmapDrawable) resultImageView.getDrawable();
if (drawable == null) {
            Toast.makeText(this, "还没有图片，请先生成", Toast.LENGTH_LONG).show();
return;
        }
        Bitmap bitmap = drawable.getBitmap();

        Map<DecodeHintType, String> hints = new HashMap<DecodeHintType, String>();
        hints.put(DecodeHintType.CHARACTER_SET, "utf-8");

// 获得待解析的图片
        RGBLuminanceSource source = new RGBLuminanceSource(bitmap);
        BinaryBitmap bitmap1 = new BinaryBitmap(new HybridBinarizer(source));
        QRCodeReader reader = new QRCodeReader();
        Result result;
try {
            result = reader.decode(bitmap1, hints);
            JSONObject json = new JSONObject(result.getText());
// 得到解析后的文字
            String str =" name: "+json.getString("name")+" \n\r title: "+json.getString("title")+" \n\r url: "+json.getString("url");
            resultTv.setText(str);

        } catch (NotFoundException e) {
            e.printStackTrace();
        } catch (ChecksumException e) {
            e.printStackTrace();
        } catch (FormatException e) {
            e.printStackTrace();
        } catch (JSONException e) {
// TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

本demo就建了两个java类（MainActivity，RGBLuminanceSource），一个布局文件（activity_main.xml），引入了一个jar包（zxing-core-2.0.jar），完整代码如下：

MainActivity

package com.lanou.zxingdemo;

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

import org.json.JSONException;
import org.json.JSONObject;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.ChecksumException;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.FormatException;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.QRCodeReader;
import com.google.zxing.qrcode.QRCodeWriter;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {
    private Button encodeBtn,decodeBtn;
    private final int QR_WIDTH = 200, QR_HEIGHT = 200;
    private ImageView resultImageView;
    private TextView resultTv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        encodeBtn = (Button) findViewById(R.id.encodeBtn);
        decodeBtn = (Button) findViewById(R.id.decodeBtn);
        encodeBtn.setOnClickListener(this);
        decodeBtn.setOnClickListener(this);

        resultImageView = (ImageView) findViewById(R.id.resultImageView);
        resultTv = (TextView) findViewById(R.id.resultTv);

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.encodeBtn:

            JSONObject json = new JSONObject(); 
            try {
                json.put("name", "xiaoxiao");
                json.put("url", "http://www.baidu.com");
                json.put("title", "title");

                createImage(json.toString());

            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
break;
        case R.id.decodeBtn:
            scanningImage();
break;
        }
    }

    // 生成QR图
    private void createImage(String content) {
        try {
            // 把输入的文本转为二维码
            Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");

            BitMatrix bitMatrix = new QRCodeWriter().encode(content,
                    BarcodeFormat.QR_CODE, QR_WIDTH, QR_HEIGHT, hints);

            int[] pixels = new int[QR_WIDTH * QR_HEIGHT];
            for (int y = 0; y < QR_HEIGHT; y++) {
                for (int x = 0; x < QR_WIDTH; x++) {
                    if (bitMatrix.get(x, y)) {
                        pixels[y * QR_WIDTH + x] = 0xff000000;
                    } else {
                        pixels[y * QR_WIDTH + x] = 0xffffffff;
                    }

                }
            }

            Bitmap bitmap = Bitmap.createBitmap(QR_WIDTH, QR_HEIGHT,
                    Bitmap.Config.ARGB_8888);

            bitmap.setPixels(pixels, 0, QR_WIDTH, 0, 0, QR_WIDTH, QR_HEIGHT);
            if (bitmap != null) {
                resultImageView.setImageBitmap(bitmap);
            }

        } catch (WriterException e) {
            e.printStackTrace();
        }
    }

    // 解析QR图片
    private void scanningImage() {
        BitmapDrawable drawable = (BitmapDrawable) resultImageView.getDrawable();
        if (drawable == null) {
            Toast.makeText(this, "还没有图片，请先生成", Toast.LENGTH_LONG).show();
            return;
        }
        Bitmap bitmap = drawable.getBitmap();

        Map<DecodeHintType, String> hints = new HashMap<DecodeHintType, String>();
        hints.put(DecodeHintType.CHARACTER_SET, "utf-8");

        // 获得待解析的图片
        RGBLuminanceSource source = new RGBLuminanceSource(bitmap);
        BinaryBitmap bitmap1 = new BinaryBitmap(new HybridBinarizer(source));
        QRCodeReader reader = new QRCodeReader();
        Result result;
        try {
            result = reader.decode(bitmap1, hints);
            JSONObject json = new JSONObject(result.getText());
            // 得到解析后的文字
            String str =" name: "+json.getString("name")+" \n\r title: "+json.getString("title")+" \n\r url: "+json.getString("url");
            resultTv.setText(str);

        } catch (NotFoundException e) {
            e.printStackTrace();
        } catch (ChecksumException e) {
            e.printStackTrace();
        } catch (FormatException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="${relativePackage}.${activityClass}" >

<LinearLayout
 android:id="@+id/linear"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >

<Button
 android:id="@+id/encodeBtn"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="生成二维码图片" />

<Button
 android:id="@+id/decodeBtn"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="解析二维码图片中的内容" />
</LinearLayout>

<ImageView
 android:id="@+id/resultImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/linear" />

<TextView
 android:id="@+id/resultTv"
android:layout_marginTop="30dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/resultImageView" />

</RelativeLayout>

代码结构：

运行效果：