Android QR Code scanner

This post is in response to queries posted by few users for my article “Android Barcode Scanner”

In this post I will re-use the code which I have written in my old post, here is a quick summery,

I have written an application to scan barcodes.
My requirement was not to depend on any other application to scan barcodes

So after some R&D online I came across an awesome library called Zxing (Zebra crossing)

This library offers scanning UPC-A, UPC-E, EAN-8, EAN-13, QR Code, RSS-14, RSS Expanded, Data Matrix, Aztec, PDF 417, Codabar, ITF, Codes 39, 93, and 128. So I will extend my old application and add feature to scan Bar code and QR code.

Step 1 : create a project and add ZXing library in you app

I have written step by step instructions on how to do this in my prevous post click here for reference.

Step 2 : update layout

We will add a button in our activity layout and add a onclick function named “scanQR”


 <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/scan_qrcode"
        android:onClick="scanQR"
        android:id="@+id/btn_qrcode"
        android:layout_marginBottom="@dimen/activity_vertical_margin" />

Step 3 : Create the method “scanQR” in your activity class

In the code below, function “scanQR” is similar to function “scanNow” detailed in my old post for scanning barcodes, except for the DesiredBarcodeFormat which is “QR_CODE_TYPES”. This is where I am selecting QR code to be scanned.

 
public void scanQR(View view){
        IntentIntegrator integrator = new IntentIntegrator(this);
        integrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE_TYPES);
        integrator.setPrompt(String.valueOf(R.string.txt_scan_qr_code));
        integrator.setResultDisplayDuration(0);     
        integrator.setCameraId(0);  // Use a specific camera of the device
        integrator.initiateScan();
    }

Below is the OnActivityResult function to handle the result. I am displaying the format and content (URL) of QR code on screen in text views you can open a browser and open the URL.


 public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        //retrieve scan result
        IntentResult scanningResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);

        if (scanningResult != null) {
            //we have a result
            String scanContent = scanningResult.getContents();
            String scanFormat = scanningResult.getFormatName();

            // display it on screen
            formatTxt.setText("FORMAT: " + scanFormat);
            contentTxt.setText("CONTENT: " + scanContent);

        }else{
            Toast toast = Toast.makeText(getApplicationContext(),"No scan data received!", Toast.LENGTH_SHORT);
            toast.show();
        }
    }

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34 Responses to “Android QR Code scanner”

May 26, 2015
Roman Reply

Hi, please, sir, the formatTxt and contentTxt is red in my Android Studio. It writes: “cannot resolve symbol-formatTxt-“. Do you know why?
- May 27, 2015
  Rajinder Deol Reply
  
  Hi Roman,
  
  these are two text views that you need to create in your layout. Check line number 18 to 26 in code here : https://github.com/rajdeol/android-barcode-scanner/blob/master/app/src/main/java/in/whomeninja/android_barcode_scanner/HomeActivity.java
June 27, 2015
Ted Reply

Hi Raj,

Thank you very very very much for these great tutorials. I had been struggling all day long trying to figure out the way to integrate Zxing github project into my project, until finally found your tutorial. They work like magics.

Could you please make another example showing the way to generate “QR code”?

Do you know anywhere to find a good documentation to use this zxing-android-embedded?
June 28, 2015
Rajinder Deol Reply

Hi Ted,

there are a lot of libraries available to generate QR code. I would recommend generating QR code on server side rather than on your device.

For server side QR code generation we have an awesome library : http://phpqrcode.sourceforge.net/

However if you still want to generate QR code in your application then we can use the same Zxing library. I will post a tutorial real soon.
July 25, 2015
wer Reply

How to add another activity that will input strings and then it will generate into qr code, can you make another example please..
July 27, 2015
Rajinder Deol Reply

Hi Wer,

I am already writing an article to generate QR code from android app, Will update the link very soon.
September 16, 2015
Alexander Reply

En el método scanQR muestra los errores:

Cannot resolve symbol txt_scan_qr_code:

integrator.setPrompt(String.valueOf(R.string.txt_scan_qr_code);

Cannot resolve method:

integrator.setResultDisplayDuration(0);
January 24, 2016
Matias Reply

Hi! thank you for this tutorial it was very usefull, i would like to know how to change the orientation of the scanner to portrait.
Thanks!!!
- February 15, 2017
  Rajinder Deol Reply
  
  Hi Matias,
  
  I have written a detailed post on how to change orientation to portrait please read : https://rajislearning.com/android-barcode-scanner-vertical-orientation-and-camera-flash/
February 22, 2016
bhawesh Reply

Hi,

I am a newbie and tried the same but getting below error while clicking scan button
CaptureActivity: Unexpected error initializing camera
java.lang.RuntimeException: Fail to connect to camera service

Any idea?
- February 22, 2016
  bhawesh Reply
  
  I Added the below snippet but no luck..
  - February 22, 2016
    bhawesh Reply
    
    uses-permission android:name=”android.permission.CAMERA”
March 25, 2016
firdaus Reply

do you have source code for this one?
- March 26, 2016
  Rajinder Deol Reply
  
  Hi Firdaus,
  
  the source code is available on my Github below is the link to the code :
  
  https://github.com/rajdeol/android-barcode-scanner
  
  The post is for Android Barcode Scanner but if you read my blog post above I have detailed the steps you need to do to make the code work for QR code scanning
  
  Regards
  Raj
April 5, 2016
chetan joshi Reply

hi sir,it is showing
Error:Execution failed for task ‘:app:dexDebug’.
com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process ‘command ‘C:\Program Files\Java\jdk1.8.0_51\bin\java.exe” finished with non-zero exit value 2
- April 30, 2016
  Rajinder Deol Reply
  
  Are you using android studio for your project..?
July 4, 2016
Ralph Reply

Hi Mr. Rajinder,

Thank you for this tutorial. I would like to ask how to continuously scan a QR Code. Thanks.
March 9, 2017
Moon Sabeen Reply

Hi Raj,

Thank you for this tutorial. Please note I am getting below error in public void scanQR(View view) method:

Cannot resolve symbol txt_scan_qr_code:
integrator.setPrompt(String.valueOf(R.string.txt_scan_qr_code);

I tried to resolve it by declaring it as a string variable, but it does not resolved. Please guide.

Thanks in advance.
- March 9, 2017
  Rajinder Deol Reply
  
  Hi Moon,
  
  That is just a prompt message on the scan screen at the bottom, what I have done in my updated code is to use a string instead of using a value from the String resource.
  
  Check my code here : https://github.com/rajdeol/android-aadhaar-card-scanner/blob/master/app/src/main/java/com/rajdeol/aadhaarreader/HomeActivity.java#L78
  
  Alternatively you can use any variable holding string value here.
  - March 12, 2017
    Moon Sabeen Reply
    
    Hello Raj,
    
    Thanks for your quick response.
    One more thing I want to share. After connecting physical device, the app starts, scan screen appears but it does not scan any QR code and gives following error:
    
    “Unfortunately QRApp has stopped”
    
    I am trying to figure out what could be the issue. I would be thankful if you can also guide in this regard.
    
    Thanking you.
    - March 15, 2017
      Rajinder Deol Reply
      
      Hi Moon,
      
      connect you android device with Android studio and put it in debug mode this will generate logs in Android studio which you can view and see the error.
      
      Errors will be visible on “log cat”, share the error output and I will have a look at it. Also please check the API version of your app as well, try and match it with API version in my app.
      - March 16, 2017
        Moon Sabeen Reply
        
        Hi Raj,
        
        Thank you for your time and response.
        
        I checked the version thing but still I get the following highlighted errors in logs. I tried to resolve but unfortunately no luck.
        (If you would suggest I can share complete logs).
        
        1) E/dalvikvm: Could not find class ‘android.graphics.drawable.RippleDrawable’, referenced from method android.support.v7.widget.AppCompatImageHelper.hasOverlappingRendering
        
        2) E/AndroidRuntime: FATAL EXCEPTION: main
        java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=49374, result=-1, data=Intent { act=com.google.zxing.client.android.SCAN flg=0x80000 (has extras) }} to activity {ad.qr_scan_app_test1/ad.qr_scan_app_test1.MainActivity}: java.lang.NullPointerException
        at android.app.ActivityThread.deliverResults(ActivityThread.java:3145)
        at android.app.ActivityThread.handleSendResult(ActivityThread.java:3188)
        at android.app.ActivityThread.access$1100(ActivityThread.java:134)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4744)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
        at dalvik.system.NativeStart.main(Native Method)
        Caused by: java.lang.NullPointerException
        at ad.qr_scan_app_test1.MainActivity.onActivityResult(MainActivity.java:81)
        at android.app.Activity.dispatchActivityResult(Activity.java:5192)
        at android.app.ActivityThread.deliverResults(ActivityThread.java:3141)
        at android.app.ActivityThread.handleSendResult(ActivityThread.java:3188)
        at android.app.ActivityThread.access$1100(ActivityThread.java:134)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4744)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
        at dalvik.system.NativeStart.main(Native Method)
        
        Thank you once again.
        
        March 17, 2017
        Rajinder Deol Reply
        
        Hi Moon,
        
        seems like you have not compiled the support libraries for your version of android sdk.
        
        Can you please share your version sdk you are using for your app.
        
        Also a useful link related to this error:
        http://stackoverflow.com/questions/37108618/could-not-find-class-android-graphics-drawable-rippledrawable
April 13, 2017
Pradnya Patil Reply

Hi Sir
Your Barcode Scanner Tutorial is very helpful for me. so Thanks
April 13, 2017
Pradnya Patil Reply

Sir I want imageslider dynamically in android
add images through admin panel see in app.
Sir please help me
- April 18, 2017
  Rajinder Deol Reply
  
  Hi Pradnya,
  
  you can use wordpress as your admin panel and it comes with a great admin panel. Then you can use wordpress REST API to fetch the uploaded images into your app. Read https://rajislearning.com/writing-secure-rest-webservices-with-php-for-android/ for WordPress REST API.
  
  Also read my post Writing Secure REST webservices with PHP for Android on how to fetch data from REST API.
April 17, 2017
jawahar Reply

Really nice post.. thank you very much bro..
- April 18, 2017
  Rajinder Deol Reply
  
  Thanks for the kind words Jawahar, let me know if you need more help.
June 9, 2017
Habib Reply

Hi,
Thanks for useful posts.
I want to know if it is possible to scan Barcode and QR code together. (I mean only by one button)

Regards,
Habib
- June 13, 2017
  Rajinder Deol Reply
  
  Hi Habib,
  
  I think you can do that but the scan will be really slow. This library scans image taken by camera to decide which barcode format is in the image and then decodes it. Specifying the format at the beginning just make the scan more quick.
November 30, 2017
admin Reply

hi,
i have two barcode matches then get the json data in dialogbox ,how to apply this
- November 30, 2017
  Rajinder Deol Reply
  
  Hi,
  
  you need to specify some more details, I think what you are saying is, you scan a QR-code and get JSON string in return. If that is the case then you need to parse the JSON string and extract the data. If you have a QR-Code which I can look at I will be able to guide you more.
  - December 22, 2017
    admin Reply
    
    Sir, i want a match barcode and get json data in android dialogbox…
    plzzz sir help me
December 22, 2017
admin Reply

sir, i want a match barcode and get json data in android dialogbox ..
plzz sir help me

Android QR Code scanner

Step 1 : create a project and add ZXing library in you app

Step 2 : update layout

Step 3 : Create the method “scanQR” in your activity class

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Android QR Code scanner

Step 1 : create a project and add ZXing library in you app

Step 2 : update layout

Step 3 : Create the method “scanQR” in your activity class

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34 Responses to “Android QR Code scanner”

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