二维码生成

首先依赖一个包

然后写builder.gradle

android {    compileSdkVersion 24    buildToolsVersion "24.0.3"    defaultConfig {        applicationId "com.bawei.myzxingdemo"        minSdkVersion 16        targetSdkVersion 24        versionCode 1        versionName "1.0"        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"    }    buildTypes {        release {            minifyEnabled false            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'        }    }}dependencies {    compile fileTree(dir: 'libs', include: ['*.jar'])    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {        exclude group: 'com.android.support', module: 'support-annotations'    })    compile 'com.android.support:appcompat-v7:24.2.1'    testCompile 'junit:junit:4.12'    compile project(':libzxing')}

xml里的布局是：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.bawei.myzxingdemo.MainActivity"    android:orientation="vertical">    <EditText        android:id="@+id/editText1"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <Button        android:id="@+id/button1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="生成二维码"/>    <ImageView        android:id="@+id/img1"        android:layout_width="150dp"        android:layout_height="150dp" />    <Button        android:id="@+id/button2"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="识别二维码（识别图片）"/>    <Button        android:id="@+id/button3"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="识别二维码（使用摄像头）"/></LinearLayout>

然后创建

RGBLuminanceSource

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;    }}

然后写Main

public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private static final int CHOOSE_PIC = 0;    private static final int PHOTO_PIC = 1;    private EditText contentEditText = null;    private ImageView qrcodeImageView = null;    private String  imgPath = null;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        setupViews();    }    private void setupViews() {        contentEditText = (EditText) findViewById(R.id.editText1);        findViewById(R.id.button1).setOnClickListener(this);        findViewById(R.id.button2).setOnClickListener(this);        findViewById(R.id.button3).setOnClickListener(this);        qrcodeImageView = (ImageView) findViewById(R.id.img1);    }    //解析二维码图片,返回结果封装在Result对象中    private com.google.zxing.Result  parseQRcodeBitmap(String bitmapPath){        //解析转换类型UTF-8        Hashtable<DecodeHintType, String> hints = new Hashtable<DecodeHintType, String>();        hints.put(DecodeHintType.CHARACTER_SET, "utf-8");        //获取到待解析的图片        BitmapFactory.Options options = new BitmapFactory.Options();        //如果我们把inJustDecodeBounds设为true，那么BitmapFactory.decodeFile(String path, Options opt)        //并不会真的返回一个Bitmap给你，它仅仅会把它的宽，高取回来给你        options.inJustDecodeBounds = true;        //此时的bitmap是null，这段代码之后，options.outWidth 和 options.outHeight就是我们想要的宽和高了        Bitmap bitmap = BitmapFactory.decodeFile(bitmapPath,options);        //我们现在想取出来的图片的边长（二维码图片是正方形的）设置为400像素        /**         options.outHeight = 400;         options.outWidth = 400;         options.inJustDecodeBounds = false;         bitmap = BitmapFactory.decodeFile(bitmapPath, options);         */        //以上这种做法，虽然把bitmap限定到了我们要的大小，但是并没有节约内存，如果要节约内存，我们还需要使用inSimpleSize这个属性        options.inSampleSize = options.outHeight / 400;        if(options.inSampleSize <= 0){            options.inSampleSize = 1; //防止其值小于或等于0        }        /**         * 辅助节约内存设置         *         * options.inPreferredConfig = Bitmap.Config.ARGB_4444;    // 默认是Bitmap.Config.ARGB_8888         * options.inPurgeable = true;         * options.inInputShareable = true;         */        options.inJustDecodeBounds = false;        bitmap = BitmapFactory.decodeFile(bitmapPath, options);        //新建一个RGBLuminanceSource对象，将bitmap图片传给此对象        RGBLuminanceSource rgbLuminanceSource = new RGBLuminanceSource(bitmap);        //将图片转换成二进制图片        BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(rgbLuminanceSource));        //初始化解析对象        QRCodeReader reader = new QRCodeReader();        //开始解析        Result result = null;        try {            result = reader.decode(binaryBitmap, hints);        } catch (Exception e) {            // TODO: handle exception        }        return result;    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        imgPath = null;        if(resultCode == RESULT_OK){            switch (requestCode) {                case CHOOSE_PIC:                    String[] proj = new String[]{MediaStore.Images.Media.DATA};                    Cursor cursor = MainActivity.this.getContentResolver().query(data.getData(), proj, null, null, null);                    if(cursor.moveToFirst()){                        int columnIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);                        System.out.println(columnIndex);                        //获取到用户选择的二维码图片的绝对路径                        imgPath = cursor.getString(columnIndex);                    }                    cursor.close();                    //获取解析结果                    Result ret = parseQRcodeBitmap(imgPath);                    Toast.makeText(MainActivity.this,"解析结果：" + ret.toString(), Toast.LENGTH_LONG).show();                    break;                case PHOTO_PIC:                    String result = data.getExtras().getString("result");                    Toast.makeText(MainActivity.this,"解析结果：" + result, Toast.LENGTH_LONG).show();                    break;                default:                    break;            }        }    }    @SuppressLint("InlinedApi")    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.button1:                //获取界面输入的内容                String content = contentEditText.getText().toString();                //判断内容是否为空                if (null == content || "".equals(content)) {                    Toast.makeText(MainActivity.this, "请输入要写入二维码的内容...",                            Toast.LENGTH_SHORT).show();                    return;                }                try {                    //生成二维码图片，第一个参数是二维码的内容，第二个参数是正方形图片的边长，单位是像素                    Bitmap qrcodeBitmap = EncodingUtils.createQRCode(content,500,500,null);                    qrcodeImageView.setImageBitmap(qrcodeBitmap);                } catch (Exception e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }                break;            case R.id.button2:                //跳转到图片选择界面去选择一张二维码图片                Intent intent1 = new Intent();//          if(android.os.Build.VERSION.SDK_INT < 19){//              intent1.setAction(Intent.ACTION_GET_CONTENT);//          }else{//              intent1.setAction(Intent.ACTION_OPEN_DOCUMENT);//          }                intent1.setAction(Intent.ACTION_PICK);                intent1.setType("image/*");                Intent intent2 =  Intent.createChooser(intent1, "选择二维码图片");                startActivityForResult(intent2, CHOOSE_PIC);                break;            case R.id.button3:                //跳转到拍照界面扫描二维码                Intent intent3 = new Intent(MainActivity.this, CaptureActivity.class);                startActivityForResult(intent3, PHOTO_PIC);                break;            default:                break;        }    }}