Android使用ZXing生成二维码

Question

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，我调用了这个方法：

 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();
    }
}

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，我收到如下错误消息：

 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$0(MainActivity.java:77)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at com.example.qrcodescan.MainActivity$2.onClick(MainActivity.java:54)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.view.View.performClick(View.java:3620)
01-30 16:37:03.101: E/AndroidRuntime(1069):     at android.view.View$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)

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

原文由 user2531590 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

我已经 在 Github 上更新了我的小型演示项目， 并在下面更新了 2022 年的答案：

将 ZXing 库添加到您的 app/build.gradle 文件中：

 implementation 'com.google.zxing:core:3.4.1'

然后在 MainActivity.java 中使用以下函数从字符串中生成二维码图像：

 Bitmap encodeAsBitmap(String str) throws WriterException {
    QRCodeWriter writer = new QRCodeWriter();
    BitMatrix bitMatrix = writer.encode(str, BarcodeFormat.QR_CODE, 400, 400);

    int w = bitMatrix.getWidth();
    int h = bitMatrix.getHeight();
    int[] pixels = new int[w * h];
    for (int y = 0; y < h; y++) {
        for (int x = 0; x < w; x++) {
            pixels[y * w + x] = bitMatrix.get(x, y) ? Color.BLACK : Color.WHITE;
        }
    }

    Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
    bitmap.setPixels(pixels, 0, w, 0, 0, w, h);
    return bitmap;
}

原文由 Alexander Farber 发布，翻译遵循 CC BY-SA 4.0 许可协议