Android 开发中使用到二维码生成和解析

• 二维码生成

• 二维码解析

  在项目的开发中, 使用二维码作为数据传递 交换 已经是常态了! 在这我也讲讲自己在项目开发中使用到的二维码.

• 生成二维码的开发流程

  1 应用google 给我们提供的zxing.jar (建议官网下载)
  2 使用zxing.jar 的MultiFormatWriter 类 生成一张二维码图片

核心代码块
/**
     * 方法说明：生成无图片二维码
     */
    @SuppressWarnings("unused")
    private Bitmap createTwoCode(String content) throws WriterException {
        BitMatrix matrix = new MultiFormatWriter().encode(content,    BarcodeFormat.QR_CODE, 300, 300);
        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] = 0xff000000;
                }
            }
        }
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

    /**
     * 方法说明：生成有图片二维码
     */
    @SuppressWarnings("unused")
    private Bitmap createTwoCode(String str, int widthAndHeight) throws WriterException {
        Hashtable<DecodeHintType, String> hints = new Hashtable<DecodeHintType, String>();
        hints.put(DecodeHintType.CHARACTER_SET, "utf-8");
        BitMatrix matrix = new MultiFormatWriter().encode(str, BarcodeFormat.QR_CODE, widthAndHeight, widthAndHeight);
        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] = 0xff000000;
                }
            }
        }
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

全整的demo 代码

(1) res/layout 布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="create2Code"
        android:text="生成二维码" />

     <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="create2Code"
        android:text="扫码" />

    <ImageView
        android:id="@+id/activity_my_coupons_pic"
        android:layout_width="300dip"
        android:layout_height="300dip"
        android:layout_gravity="center" />

</LinearLayout>

(2) activity 中代码块

package com.gghl.view.wheelcity;

import java.util.Hashtable;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.zf.iosdialog.R;

public class NagitestActivty extends Activity {

    private ImageView activity_my_coupons_pic;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.nagi_testactivity);
        activity_my_coupons_pic = (ImageView) this.findViewById(R.id.activity_my_coupons_pic);
    }

    //生成二维码
    public void create2Code(View view) throws WriterException{
        String content = "毅神之怒";
        Bitmap bmp = createTwoCode(content,300);
        Bitmap logoBmp = small(BitmapFactory.decodeResource(getResources(), R.drawable.app_icon));
        Bitmap bitmap = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(bmp, 0, 0, null);
        canvas.drawBitmap(logoBmp, bmp.getWidth() / 2 - logoBmp.getWidth() / 2, bmp.getHeight() / 2 - logoBmp.getHeight() / 2, null);
        activity_my_coupons_pic.setImageBitmap(bitmap);
    }

    /**
     * 方法说明：生成无图片二维码
     */
    @SuppressWarnings("unused")
    private Bitmap createTwoCode(String content) throws WriterException {
        BitMatrix matrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, 300, 300);
        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] = 0xff000000;
                }
            }
        }
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

    /**
     * 方法说明：生成有图片二维码
     */
    @SuppressWarnings("unused")
    private Bitmap createTwoCode(String str, int widthAndHeight) throws WriterException {
        Hashtable<DecodeHintType, String> hints = new Hashtable<DecodeHintType, String>();
        hints.put(DecodeHintType.CHARACTER_SET, "utf-8");
        BitMatrix matrix = new MultiFormatWriter().encode(str, BarcodeFormat.QR_CODE, widthAndHeight, widthAndHeight);
        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] = 0xff000000;
                }
            }
        }
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

    /**
     * 方法说明：缩小Bitmap
     */
    @SuppressWarnings("unused")
    private static Bitmap small(Bitmap bitmap) {
        Matrix matrix = new Matrix();
        matrix.postScale(0.2f, 0.2f);
        Bitmap resizeBmp = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
                bitmap.getHeight(), matrix, true);
        return resizeBmp;
    }
}

最后的效果:

呵呵, 可以试试使用微信或支付宝扫一扫~~~~ 但是当在真实的项目中,大家改吧改吧就是你们的了!

二维码的扫描

对于二维码的扫描,我只是简单说说原理;
其实在二维码扫描就是读取二维码图片中信息, zxing.jar 也一样的封装好在LuminanceSource.Java 中

  // 解析QR图片
private void scanningImage() {

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

        // 获得待解析的图片
        Bitmap bitmap = ((BitmapDrawable) qr_image.getDrawable()).getBitmap();
        RGBLuminanceSource source = new RGBLuminanceSource(bitmap);
        BinaryBitmap bitmap1 = new BinaryBitmap(new HybridBinarizer(source));
        QRCodeReader reader = new QRCodeReader();
        Result result;
        try {
            result = reader.decode(bitmap1);
            result=reader.decode(bitmap1, hints );
            // 得到解析后的文字
            qr_result.setText(result.getText());
        } catch (NotFoundException e) {
            e.printStackTrace();
        } catch (ChecksumException e) {
            e.printStackTrace();
        } catch (FormatException e) {
            e.printStackTrace();
        }
    }

zxing.jar 中LuminanceSource 核心类

package com.example.ecodetest;

/*
* Copyright 2009 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

import java.io.FileNotFoundException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import com.google.zxing.LuminanceSource;

public final class RGBLuminanceSource extends LuminanceSource { 

       private final byte[] luminances; 

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

       public RGBLuminanceSource(Bitmap bitmap) { 
         super(bitmap.getWidth(), bitmap.getHeight()); 

         int width = bitmap.getWidth(); 
         int height = bitmap.getHeight(); 
         int[] pixels = new int[width * height]; 
         bitmap.getPixels(pixels, 0, width, 0, 0, width, height); 

         // In order to measure pure decoding speed, we convert the entire image to a greyscale array 
         // up front, which is the same as the Y channel of the YUVLuminanceSource in the real app. 
         luminances = new byte[width * height]; 
         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; 
             if (r == g && g == b) { 
               // Image is already greyscale, so pick any channel. 
               luminances[offset + x] = (byte) r; 
             } else { 
               // Calculate luminance cheaply, favoring green. 
               luminances[offset + x] = (byte) ((r + g + g + b) >> 2); 
             } 
           } 
         } 
       } 

       public byte[] getRow(int y, byte[] row) { 
         if (y < 0 || y >= getHeight()) { 
           throw new IllegalArgumentException("Requested row is outside the image: " + y); 
         } 
         int width = getWidth(); 
         if (row == null || row.length < width) { 
           row = new byte[width]; 
         } 

         System.arraycopy(luminances, y * width, row, 0, width); 
         return row; 
       } 

       // Since this class does not support cropping, the underlying byte array already contains 
       // exactly what the caller is asking for, so give it to them without a copy. 
       public byte[] getMatrix() { 
         return luminances; 
       } 

       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; 
       } 

     } 

看到这里大家可能有一个疑问, 二维码支付是什么做的!

这个时候就是需要与服务器进行交互了, 在我做的这个第三方支付项目中,

我们通过一个Timer定时器不断从访问服务询问用户客户端是否已经支付,

这有点像tcp 协议中的三次握手;

 Timer timer = new Timer();
    TimerTask task = new TimerTask() {
        @Override
        public void run() {

            runOnUiThread(new Runnable() {      // UI thread
                @Override
                public void run() {
                    recLen--;
                    if(recLen < 0){
                        //获得支付状态
                        getPayStatus();
                        recLen = 3;

                    }
                }
            });
        }
    };
    timer.schedule(task, 1000, 1000); 

如果大家在这一点还是不理解的话, 大家可以看看支付宝的支付宝二维码管理接口api 文档

里面的写的非常详细.

duang~~~ 最后相信大家基本了解二维码了吧!