我正在尝试使用ML Kit在android studio中构建条形码扫描仪。我有一个可以正常工作的代码，它仅检测QR码。我想让条形码扫描仪读取所有类型的条形码，主要是用于食品的条形码。我试图获取条形码的原始值，以便在数据库中进行搜索并将相关信息显示在屏幕上。
下面是我用来检测QR码的代码。
public class MainActivity extends AppCompatActivity {
CameraView camera_view;
boolean isDetected = false;
private Button btn_start_again;
FirebaseVisionBarcodeDetectorOptions options;
FirebaseVisionBarcodeDetector detector;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Dexter.withActivity(this)
.withPermissions(new String [] {Manifest.permission.CAMERA,Manifest.permission.RECORD_AUDIO})
.withListener(new MultiplePermissionsListener() {
@Override
public void onPermissionsChecked(MultiplePermissionsReport report) {
setUpCamera();
}
@Override
public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {
Toast.makeText(getApplicationContext(),"You must accept the permissions",Toast.LENGTH_LONG).show();
}
}).check();
}
private void setUpCamera() {
btn_start_again =(Button)findViewById(R.id.btn_again);
btn_start_again.setEnabled(false);
btn_start_again.setOnClickListener((View v) -> isDetected = !isDetected);
camera_view = (CameraView) findViewById(R.id.cameraview);
camera_view.setLifecycleOwner(this);
camera_view.addFrameProcessor(new FrameProcessor() {
@Override
public void process(@NonNull Frame frame) {
processImage(getVisionImageFromFrame(frame));
}
});
FirebaseVisionBarcodeDetectorOptions options =
new FirebaseVisionBarcodeDetectorOptions.Builder()
.setBarcodeFormats(
FirebaseVisionBarcode.FORMAT_QR_CODE,
FirebaseVisionBarcode.FORMAT_AZTEC)
.build();
detector = FirebaseVision.getInstance().getVisionBarcodeDetector(options);
}
private void processImage(FirebaseVisionImage image) {
if(!isDetected){
detector.detectInImage(image)
.addOnSuccessListener(new OnSuccessListener<List<FirebaseVisionBarcode>>() {
@Override
public void onSuccess(List<FirebaseVisionBarcode> firebaseVisionBarcodes) {
processResult(firebaseVisionBarcodes);
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(getApplicationContext(),"e.getMessage()",Toast.LENGTH_LONG).show();
}
});
}
}
private void processResult(List<FirebaseVisionBarcode> firebaseVisionBarcodes) {
if(firebaseVisionBarcodes.size() > 0 ){
isDetected = true;
btn_start_again.setEnabled(isDetected);
for (FirebaseVisionBarcode item:firebaseVisionBarcodes){
Rect bounds = item.getBoundingBox();
Point[] corners = item.getCornerPoints();
String rawValue = item.getRawValue();
int value_type = item.getValueType();
switch (value_type){
case FirebaseVisionBarcode.TYPE_TEXT:
{
createDialog(item.getRawValue());
}
break;
case FirebaseVisionBarcode.TYPE_URL:
{
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(item.getRawValue()));
startActivity(intent);
}
case FirebaseVisionBarcode.TYPE_CONTACT_INFO:
{
String info = new StringBuilder("Name:")
/*.append(item.getContactInfo().getName().getFormattedName())
.append("\n")*/
.append("Address")
.append(item.getContactInfo().getAddresses().get(0).getAddressLines())
.append("\n")
.append("Email:")
.append(item.getContactInfo().getEmails().get(0).getAddress())
.toString();
createDialog(info);
}
break;
default:
{
createDialog(rawValue);
}
break;
}
}
}
}
private void createDialog(String text) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(text);
builder.setPositiveButton("OK", ((DialogInterface dialog, int i) -> dialog.dismiss()));
AlertDialog dialog = builder.create();
dialog.show();
}
private FirebaseVisionImage getVisionImageFromFrame(Frame frame) {
byte[] data = frame.getData();
FirebaseVisionImageMetadata metadata = new FirebaseVisionImageMetadata.Builder()
.setFormat(FirebaseVisionImageMetadata.IMAGE_FORMAT_NV21)
.setHeight(frame.getSize().getHeight())
.setWidth(frame.getSize().getWidth())
.build();
//.setRotation(frame.getRotation())
return FirebaseVisionImage.fromByteArray(data,metadata);
}
}
答案 0 :(得分：2)
您还有硬件问题。
Android设备的摄像头通常仅在条形码正确聚焦的情况下读取条形码，而条形码仅在后置摄像头发生，因为前置摄像头通常不具有自动对焦功能。
相反，即使没有很好地聚焦QR码，也会读取它们。
此外，普通相机的条形码读取速度较慢，如果您希望使用内置条形码读取器快速读取所有代码的设备寻找条形码，则它们被称为PDA，尽管它们比智能手机贵得多。