Java Android 使用 ZXing 生成二维码

Android Using ZXing Generate QR Code

提问by

I was having some problem when trying to generate QR code in Android Programming. Here is the TutorialI followed. When my generate button on click, I am calling this method:

尝试在 Android 编程中生成二维码时遇到了一些问题。这是我遵循的教程。当我点击生成按钮时，我正在调用这个方法：

private void generateQR(){
    String qrInputText = "test";

    //Find screen size
    WindowManager manager = (WindowManager) getSystemService(WINDOW_SERVICE);
    Display display = manager.getDefaultDisplay();
    Point point = new Point();
    display.getSize(point);
    int width = point.x;
    int height = point.y;
    int smallerDimension = width < height ? width : height;
    smallerDimension = smallerDimension * 3/4;

    //Encode with a QR Code image
    QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(
        qrInputText, 
        null, 
        Contents.Type.TEXT,  
        BarcodeFormat.QR_CODE.toString(), 
        smallerDimension
    );
    try {
        Bitmap bitmap = qrCodeEncoder.encodeAsBitmap();
        ImageView myImage = (ImageView) findViewById(R.id.ivImage);
        myImage.setImageBitmap(bitmap);
    } catch (WriterException e) {
        e.printStackTrace();
    }
}

And then for the QRCodeEncoder and Contents classes, I followed the one in the tutorial. However, when I click on generate, I am getting the error message as:

然后对于 QRCodeEncoder 和 Contents 类，我遵循了教程中的那个。但是，当我单击生成时，我收到错误消息：

01-30 16:37:03.093: I/dalvikvm(1069): Could not find method com.google.zxing.BarcodeFormat.valueOf, referenced from method com.example.qrcodescan.QRCodeEncoder.encodeContents
01-30 16:37:03.093: W/dalvikvm(1069): VFY: unable to resolve static method 338: Lcom/google/zxing/BarcodeFormat;.valueOf (Ljava/lang/String;)Lcom/google/zxing/BarcodeFormat;
01-30 16:37:03.093: D/dalvikvm(1069): VFY: replacing opcode 0x71 at 0x0005
01-30 16:37:03.093: W/dalvikvm(1069): VFY: unable to resolve static field 287 (QR_CODE) in Lcom/google/zxing/BarcodeFormat;
01-30 16:37:03.093: D/dalvikvm(1069): VFY: replacing opcode 0x62 at 0x0011
01-30 16:37:03.093: W/dalvikvm(1069): VFY: unable to resolve static field 287 (QR_CODE) in Lcom/google/zxing/BarcodeFormat;
01-30 16:37:03.093: D/dalvikvm(1069): VFY: replacing opcode 0x62 at 0x0015
01-30 16:37:03.093: W/dalvikvm(1069): VFY: unable to resolve static field 294 (CHARACTER_SET) in Lcom/google/zxing/EncodeHintType;
01-30 16:37:03.093: D/dalvikvm(1069): VFY: replacing opcode 0x62 at 0x0018
01-30 16:37:03.093: E/dalvikvm(1069): Could not find class 'com.google.zxing.MultiFormatWriter', referenced from method com.example.qrcodescan.QRCodeEncoder.encodeAsBitmap
01-30 16:37:03.093: W/dalvikvm(1069): VFY: unable to resolve new-instance 150 (Lcom/google/zxing/MultiFormatWriter;) in Lcom/example/qrcodescan/QRCodeEncoder;
01-30 16:37:03.093: D/dalvikvm(1069): VFY: replacing opcode 0x22 at 0x001d
01-30 16:37:03.093: D/dalvikvm(1069): DexOpt: unable to opt direct call 0x0159 at 0x1f in Lcom/example/qrcodescan/QRCodeEncoder;.encodeAsBitmap
01-30 16:37:03.093: D/AndroidRuntime(1069): Shutting down VM
01-30 16:37:03.093: W/dalvikvm(1069): threadid=1: thread exiting with uncaught exception (group=0x40c341f8)
01-30 16:37:03.101: E/AndroidRuntime(1069): FATAL EXCEPTION: main
01-30 16:37:03.101: E/AndroidRuntime(1069): java.lang.NoClassDefFoundError: com.google.zxing.BarcodeFormat
01-30 16:37:03.101: E/AndroidRuntime(1069):     at com.example.qrcodescan.MainActivity.generateQR(MainActivity.java:95)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at com.example.qrcodescan.MainActivity.access
dependencies {
    ....
    compile 'com.google.zxing:core:3.2.1'
}
(MainActivity.java:77)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at com.example.qrcodescan.MainActivity.onClick(MainActivity.java:54)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.view.View.performClick(View.java:3620)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.view.View$PerformClick.run(View.java:14292)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.os.Handler.handleCallback(Handler.java:605)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.os.Handler.dispatchMessage(Handler.java:92)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.os.Looper.loop(Looper.java:137)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.app.ActivityThread.main(ActivityThread.java:4512)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at java.lang.reflect.Method.invokeNative(Native Method)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at java.lang.reflect.Method.invoke(Method.java:511)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:982)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:749)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at dalvik.system.NativeStart.main(Native Method)

I did added the core.jar under libs folder. Any ideas? Thanks in advance.

我确实在 libs 文件夹下添加了 core.jar。有任何想法吗？提前致谢。

回答by Alexander Farber

Here is how you can generate an image with QR code from a string -

以下是如何从字符串中生成带有二维码的图像 -

First add the following line to build.gradlefile in your Android Studioproject:

首先将以下行添加到Android Studio项目中的build.gradle文件：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ImageView imageView = (ImageView) findViewById(R.id.qrCode);
    try {
        Bitmap bitmap = encodeAsBitmap(STR);
        imageView.setImageBitmap(bitmap);
    } catch (WriterException e) {
        e.printStackTrace();
    }
}

Bitmap encodeAsBitmap(String str) throws WriterException {
    BitMatrix result;
    try {
        result = new MultiFormatWriter().encode(str, 
            BarcodeFormat.QR_CODE, WIDTH, WIDTH, null);
    } catch (IllegalArgumentException iae) {
        // Unsupported format
        return null;
    }
    int w = result.getWidth();
    int h = result.getHeight();
    int[] pixels = new int[w * h];
    for (int y = 0; y < h; y++) {
        int offset = y * w;
        for (int x = 0; x < w; x++) {
            pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
        }
    }
    Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
    bitmap.setPixels(pixels, 0, width, 0, 0, w, h);
    return bitmap;
}

Or if still using Eclipse with ADT-pluginadd ZXing's core.jarfrom Maven repositoryto the libssubdir of your Eclipse ADT project (here fullscreen):

或者，如果仍然使用带有 ADT 插件的 Eclipse，请将 ZXing 的core.jar从Maven 存储库添加到Eclipse ADT 项目的libs子目录（此处为全屏）：

And then use the sample code from my MainActivity.java:

然后使用我的MainActivity.java 中的示例代码：

public static int white = 0xFFFFFFFF;
public static int black = 0xFF000000;
public final static int WIDTH = 500;


try
    {
        Bitmap bmp =  encodeAsBitmap("Life is a bitch");
        imgView.setImageBitmap(bmp);
    } catch (Exception e) {
        e.printStackTrace();
    }


Bitmap encodeAsBitmap(String str) throws WriterException {
    BitMatrix result;
    Bitmap bitmap=null;
    try
    {
        result = new MultiFormatWriter().encode(str,
                BarcodeFormat.QR_CODE, WIDTH, WIDTH, null);

        int w = result.getWidth();
        int h = result.getHeight();
        int[] pixels = new int[w * h];
        for (int y = 0; y < h; y++) {
            int offset = y * w;
            for (int x = 0; x < w; x++) {
                pixels[offset + x] = result.get(x, y) ? black:white;
            }
        }
        bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, WIDTH, 0, 0, w, h);
    } catch (Exception iae) {
        iae.printStackTrace();
        return null;
    }
    return bitmap;
}

回答by Anirudh

compile 'com.google.zxing:core:3.2.1'

回答by user6017633

ZXing library can provide easy way.

ZXing 库可以提供简单的方法。

Origin is : Generate QRCode Android Example

来源是：生成二维码 Android 示例

add in dependencies

添加依赖项

private Bitmap TextToImageEncode(String Value) throws WriterException {
        BitMatrix bitMatrix;
        try {
            bitMatrix = new MultiFormatWriter().encode(
                    Value,
                    BarcodeFormat.DATA_MATRIX.QR_CODE,
                    QRcodeWidth, QRcodeWidth, null
            );

        } catch (IllegalArgumentException Illegalargumentexception) {

            return null;
        }
        int bitMatrixWidth = bitMatrix.getWidth();

        int bitMatrixHeight = bitMatrix.getHeight();

        int[] pixels = new int[bitMatrixWidth * bitMatrixHeight];

        for (int y = 0; y < bitMatrixHeight; y++) {
            int offset = y * bitMatrixWidth;

            for (int x = 0; x < bitMatrixWidth; x++) {

                pixels[offset + x] = bitMatrix.get(x, y) ?
                        getResources().getColor(R.color.black):getResources().getColor(R.color.white);
            }
        }
        Bitmap bitmap = Bitmap.createBitmap(bitMatrixWidth, bitMatrixHeight, Bitmap.Config.ARGB_4444);

        bitmap.setPixels(pixels, 0, 500, 0, 0, bitMatrixWidth, bitMatrixHeight);
        return bitmap;
    }

Here is the method to conver string into QR Image

这是将字符串转换为 QR 图像的方法

 public String saveImage(Bitmap myBitmap) {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        myBitmap.compress(Bitmap.CompressFormat.JPEG, 90, bytes);
        File wallpaperDirectory = new File(
                Environment.getExternalStorageDirectory() + IMAGE_DIRECTORY);
        // have the object build the directory structure, if needed.

        if (!wallpaperDirectory.exists()) {
            Log.d("dirrrrrr", "" + wallpaperDirectory.mkdirs());
            wallpaperDirectory.mkdirs();
        }

        try {
            File f = new File(wallpaperDirectory, Calendar.getInstance()
                    .getTimeInMillis() + ".jpg");
            f.createNewFile();   //give read write permission
            FileOutputStream fo = new FileOutputStream(f);
            fo.write(bytes.toByteArray());
            MediaScannerConnection.scanFile(this,
                    new String[]{f.getPath()},
                    new String[]{"image/jpeg"}, null);
            fo.close();
            Log.d("TAG", "File Saved::--->" + f.getAbsolutePath());

            return f.getAbsolutePath();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        return "";

    }

Save geneated qr image

保存生成的 qr 图像

...
String QRcode = "...";
new generateQrcode(qrcodeImageview).execute(QRcode);
...
private class generateQrcode extends AsyncTask<String, Void, Bitmap> {
        public final static int WIDTH = 400;
        ImageView bmImage;

        public generateQrcode(ImageView bmImage) {
            this.bmImage = bmImage;
        }

        protected Bitmap doInBackground(String... urls) {
            String Value = urls[0];
            com.google.zxing.Writer writer = new QRCodeWriter();
            Bitmap bitmap = null;
            BitMatrix bitMatrix = null;
            try {
                bitMatrix = writer.encode(Value, com.google.zxing.BarcodeFormat.QR_CODE, WIDTH, WIDTH,
                        ImmutableMap.of(EncodeHintType.MARGIN, 1));
                bitmap = Bitmap.createBitmap(400, 400, Bitmap.Config.ARGB_8888);
                for (int i = 0; i < 400; i++) {
                    for (int j = 0; j < 400; j++) {
                        bitmap.setPixel(i, j, bitMatrix.get(i, j) ? Color.BLACK
                                : Color.WHITE);
                    }
                }
            } catch (WriterException e) {
                e.printStackTrace();
            }
            return bitmap;
        }

        protected void onPostExecute(Bitmap result) {
            bmImage.setImageBitmap(result);
        }
    }

回答by Programmer

Following code worked for me:

以下代码对我有用：

##代码##