我正在使用新的 google plays 服务:条形码检测器，对于这个海豚，我正在学习这个教程:https://search-codelabs.appspot.com/codelabs/bar-codes
但是当我在我的真实设备(Asus Nexus 7)上运行应用程序时，应用程序的 TextView 总是显示“无法设置检测器”，我不知道如何让它工作 > < ...
这里是一些用于快速调试的代码:
public class DecoderBar extends Activity implements View.OnClickListener{
private TextView txt;
private ImageView img;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_decoder);
Button b = (Button) findViewById(R.id.button);
txt = (TextView) findViewById(R.id.txtContent);
img = (ImageView) findViewById(R.id.imgview);
b.setOnClickListener(this);
}
// [...]
@Override
public void onClick(View v) {
Bitmap myBitmap = BitmapFactory.decodeResource(getApplicationContext().getResources(),R.drawable.popi);
img.setImageBitmap(myBitmap);
BarcodeDetector detector = new BarcodeDetector.Builder(getApplicationContext())
.setBarcodeFormats(Barcode.DATA_MATRIX | Barcode.QR_CODE)
.build();
if(!detector.isOperational()){
// Always show this message, so, never is operational!
txt.setText("Could not set up the detector!");
return;
}
Frame frame = new Frame.Builder().setBitmap(myBitmap).build();
SparseArray<Barcode> barcodes = detector.detect(frame);
Barcode thisCode = barcodes.valueAt(0);
txt.setText(thisCode.rawValue);
}
}
最佳答案
看起来像是第一次在每台设备上使用条形码检测器，一些下载是由 Google Play 服务完成的。这是链接:
https://developers.google.com/vision/multi-tracker-tutorial
这是摘录:
The first time that an app using barcode and/or face APIs is installed on a device, GMS will download a libraries to the device in order to do barcode and face detection. Usually this is done by the installer before the app is run for the first time.
关于java - detector.isOperational() 在 android 上总是 false，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32202685/