How to read barcodes with the camera on Android?
I want my application to recognize barcodes taken by camera. Is it possibl开发者_开发百科e using Android SDK?
Something like this: Barcode Scanner
It's not built into the SDK, but you can use the Zxing library. It's free, open source, and Apache-licensed.
The 2016 recommendation is to use the Barcode API, which also works offline.
2016 update
With the latest release of Google Play Services, v7.8, you have access to the new Mobile Vision API. That's probably the most convenient way to implement barcode scanning now, and it also works offline.
From the Android Barcode API:
The Barcode API detects barcodes in real-time, on device, in any orientation. It can also detect multiple barcodes at once.
It reads the following barcode formats:
- 1D barcodes: EAN-13, EAN-8, UPC-A, UPC-E, Code-39, Code-93, Code-128, ITF, Codabar
- 2D barcodes: QR Code, Data Matrix, PDF-417, AZTEC
It automatically parses QR Codes, Data Matrix, PDF-417, and Aztec values, for the following supported formats:
- URL
- Contact information (VCARD, etc.)
- Calendar event
- Phone
- SMS
- ISBN
- WiFi
- Geo-location (latitude and longitude)
- AAMVA driver license/ID
Here is sample code using camera api
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseArray;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.io.IOException;
import com.google.android.gms.vision.CameraSource;
import com.google.android.gms.vision.Detector;
import com.google.android.gms.vision.Frame;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;
public class MainActivity extends AppCompatActivity {
TextView barcodeInfo;
SurfaceView cameraView;
CameraSource cameraSource;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
cameraView = (SurfaceView) findViewById(R.id.camera_view);
barcodeInfo = (TextView) findViewById(R.id.txtContent);
BarcodeDetector barcodeDetector =
new BarcodeDetector.Builder(this)
.setBarcodeFormats(Barcode.CODE_128)//QR_CODE)
.build();
cameraSource = new CameraSource
.Builder(this, barcodeDetector)
.setRequestedPreviewSize(640, 480)
.build();
cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
cameraSource.start(cameraView.getHolder());
} catch (IOException ie) {
Log.e("CAMERA SOURCE", ie.getMessage());
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
cameraSource.stop();
}
});
barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
@Override
public void release() {
}
@Override
public void receiveDetections(Detector.Detections<Barcode> detections) {
final SparseArray<Barcode> barcodes = detections.getDetectedItems();
if (barcodes.size() != 0) {
barcodeInfo.post(new Runnable() { // Use the post method of the TextView
public void run() {
barcodeInfo.setText( // Update the TextView
barcodes.valueAt(0).displayValue
);
}
});
}
}
});
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
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.example.gateway.cameraapibarcode.MainActivity">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<SurfaceView
android:layout_width="640px"
android:layout_height="480px"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"
android:id="@+id/camera_view"/>
<TextView
android:text=" code reader"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/txtContent"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Process"
android:id="@+id/button"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imgview"/>
</LinearLayout>
</RelativeLayout>
build.gradle(Module:app)
add compile 'com.google.android.gms:play-services:7.8.+' in dependencies
Here is a sample code: my app uses ZXing Barcode Scanner.
You need these 2 classes: IntentIntegrator and IntentResult
Call scanner (e.g. OnClickListener, OnMenuItemSelected...), "PRODUCT_MODE" - it scans standard 1D barcodes (you can add more).:
IntentIntegrator.initiateScan(this, "Warning", "ZXing Barcode Scanner is not installed, download?", "Yes", "No", "PRODUCT_MODE");Get barcode as a result:
public void onActivityResult(int requestCode, int resultCode, Intent intent) { switch (requestCode) { case IntentIntegrator.REQUEST_CODE: if (resultCode == Activity.RESULT_OK) { IntentResult intentResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent); if (intentResult != null) { String contents = intentResult.getContents(); String format = intentResult.getFormatName(); this.elemQuery.setText(contents); this.resume = false; Log.d("SEARCH_EAN", "OK, EAN: " + contents + ", FORMAT: " + format); } else { Log.e("SEARCH_EAN", "IntentResult je NULL!"); } } else if (resultCode == Activity.RESULT_CANCELED) { Log.e("SEARCH_EAN", "CANCEL"); } } }
contents holds barcode number
module app:
implementation 'com.google.zxing:core:3.2.1'
implementation 'com.journeyapps:zxing-android-embedded:3.2.0@aar'
AndroidManifest.xml
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus"/>
MainActivity.java
public class MainActivity extends AppCompatActivity {
Button BarCode;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
BarCode = findViewById(R.id.button_barcode);
final Activity activity = this;
BarCode.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
IntentIntegrator intentIntegrator = new IntentIntegrator(activity);
intentIntegrator.setDesiredBarcodeFormats(intentIntegrator.ALL_CODE_TYPES);
intentIntegrator.setBeepEnabled(false);
intentIntegrator.setCameraId(0);
intentIntegrator.setPrompt("SCAN");
intentIntegrator.setBarcodeImageEnabled(false);
intentIntegrator.initiateScan();
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
IntentResult Result = IntentIntegrator.parseActivityResult(requestCode , resultCode ,data);
if(Result != null){
if(Result.getContents() == null){
Log.d("MainActivity" , "cancelled scan");
Toast.makeText(this, "cancelled", Toast.LENGTH_SHORT).show();
}
else {
Log.d("MainActivity" , "Scanned");
Toast.makeText(this,"Scanned -> " + Result.getContents(), Toast.LENGTH_SHORT).show();
}
}
else {
super.onActivityResult(requestCode , resultCode , data);
}
}
}
You can also use barcodefragmentlib which is an extension of zxing but provides barcode scanning as fragment library, so can be very easily integrated.
Here is the supporting documentation for usage of library
With Google Firebase ML Kit's barcode scanning API, you can read data encoded using most standard barcode formats.
https://firebase.google.com/docs/ml-kit/read-barcodes?authuser=0
You can follow this link to read barcodes efficiently.
There are two parts in building barcode scanning feature, one capturing barcode image using camera and second extracting barcode value from the image.
Barcode image can be captured from your app using camera app and barcode value can be extracted using Firebase Machine Learning Kit barcode scanning API.
Here is an example app https://www.zoftino.com/android-barcode-scanning-example
Firebase Barcode scanning API has been deprecated.
You can use Googles ML Kit to recognize and decode barcodes without help of firebase.
Add in your gradle(app)
implementation 'com.google.mlkit:barcode-scanning:17.1.1'
for more details have a look on this official guideline
I had an issue with the parseActivityForResult arguments. I got this to work:
package JMA.BarCodeScanner;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class JMABarcodeScannerActivity extends Activity {
Button captureButton;
TextView tvContents;
TextView tvFormat;
Activity activity;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
activity = this;
captureButton = (Button)findViewById(R.id.capture);
captureButton.setOnClickListener(listener);
tvContents = (TextView)findViewById(R.id.tvContents);
tvFormat = (TextView)findViewById(R.id.tvFormat);
}
public void onActivityResult(int requestCode, int resultCode, Intent intent)
{
switch (requestCode)
{
case IntentIntegrator.REQUEST_CODE:
if (resultCode == Activity.RESULT_OK)
{
IntentResult intentResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
if (intentResult != null)
{
String contents = intentResult.getContents();
String format = intentResult.getFormatName();
tvContents.setText(contents.toString());
tvFormat.setText(format.toString());
//this.elemQuery.setText(contents);
//this.resume = false;
Log.d("SEARCH_EAN", "OK, EAN: " + contents + ", FORMAT: " + format);
} else {
Log.e("SEARCH_EAN", "IntentResult je NULL!");
}
}
else if (resultCode == Activity.RESULT_CANCELED) {
Log.e("SEARCH_EAN", "CANCEL");
}
}
}
private View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View v) {
IntentIntegrator integrator = new IntentIntegrator(activity);
integrator.initiateScan();
}
};
}
Latyout for Activity:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:id="@+id/capture"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Take a Picture"/>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/tvContents"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/tvFormat"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
加载中,请稍侯......
精彩评论