[android] Android, How to read QR code in my application?

In my application I need to read Qr code. I searched the net and found Zing codes however lots of developers had problem with using it and it seems it is buggy!

If i assume that my customers has qr reader installed on their device, how can i use those applications and call them via implicit intents?

if user doesn't have any qr reader, what will happen to the application? if it crashes, may i ask user to download for example QrDroid and after that use it?

Use a QR library like ZXing... I had very good experience with it, QrDroid is much buggier. If you must rely on an external reader, rely on a standard one like Google Goggles!

I've created a simple example tutorial. You can read this and use in your application.

http://ribinsandroidhelper.blogspot.in/2013/03/qr-code-reading-on-your-application.html

Through this link you can download the qrcode library project and import into your workspace and add library to your project

and copy this code to your activity

 Intent intent = new Intent("com.google.zxing.client.android.SCAN");
 startActivityForResult(intent, 0);

 public void onActivityResult(int requestCode, int resultCode, Intent intent) {
     if (requestCode == 0) {
         if (resultCode == RESULT_OK) {
             String contents = intent.getStringExtra("SCAN_RESULT");
             String format = intent.getStringExtra("SCAN_RESULT_FORMAT");
             Toast.makeText(this, contents,Toast.LENGTH_LONG).show();
             // Handle successful scan
         } else if (resultCode == RESULT_CANCELED) {
             //Handle cancel
         }
     }
}

if user doesn't have any qr reader, what will happen to the application? if it crashes, may i ask user to download for example QrDroid and after that use it?

Interestingly, Google now introduced Mobile Vision APIs, they are integrated in play services itself.

In your Gradle file just add:

compile 'com.google.android.gms:play-services-vision:11.4.0'

Taken from this QR code tutorial.

UPDATE 2020:

Now QR code scanning is also a part of ML Kit, so you can bundle the model inside the app and use it by integrating the following gradle dependency:

dependencies {
  // ...
  // Use this dependency to bundle the model with your app
  implementation 'com.google.mlkit:barcode-scanning:16.0.3'
}

Or you can use the following gradle dependency to dynamically download the models from Google Play Services:

dependencies {
  // ...
  // Use this dependency to use the dynamically downloaded model in Google Play Services
  implementation 'com.google.android.gms:play-services-mlkit-barcode-scanning:16.1.2'
}

Taken from this link.

In android studio, You can use bellow process to create & Read QR Code &image look like bellw

1. Create a android studio empty project

2. Add library in app.gradle

   compile 'com.google.zxing:core:3.2.1'
   compile 'com.journeyapps:zxing-android-embedded:3.2.0@aar'
   

3. In activity.main xml use bellow..

    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.enamul.qrcode.MainActivity">
   
   <LinearLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:layout_margin="20dp"
     android:orientation="vertical">
   
   
   <EditText
       android:id="@+id/editText"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:gravity="center"
       android:hint="Enter Text Here" />
   
   <Button
       android:id="@+id/button"
       android:layout_width="fill_parent"
       android:layout_height="50dp"
       android:layout_below="@+id/editText"
       android:text="Click Here TO generate qr code"
       android:textAllCaps="false"
       android:textSize="16sp" />
   
   
   <Button
       android:id="@+id/btnScan"
       android:layout_width="fill_parent"
       android:layout_height="50dp"
       android:layout_below="@+id/editText"
       android:text="Scan Your QR Code"
       android:textAllCaps="false"
       android:textSize="16sp" />
   
   <TextView
       android:id="@+id/tv_qr_readTxt"
       android:layout_width="match_parent"
       android:layout_height="wrap_content" />
   
   
   <ImageView
       android:id="@+id/imageView"
       android:layout_width="match_parent"
       android:layout_height="200dp"
       android:layout_below="@+id/button"
       android:src="@android:drawable/ic_dialog_email" />
   
   
   </LinearLayout>
   
   </LinearLayout>
   

4. In MainActivity you can use bellow code

   public class MainActivity extends AppCompatActivity {
     ImageView imageView;
     Button button;
     Button btnScan;
     EditText editText;
     String EditTextValue ;
     Thread thread ;
     public final static int QRcodeWidth = 350 ;
     Bitmap bitmap ;
   
     TextView tv_qr_readTxt;
   
    @Override
    protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
   
       imageView = (ImageView)findViewById(R.id.imageView);
       editText = (EditText)findViewById(R.id.editText);
       button = (Button)findViewById(R.id.button);
       btnScan = (Button)findViewById(R.id.btnScan);
        tv_qr_readTxt = (TextView) findViewById(R.id.tv_qr_readTxt);
   
   button.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View view) {
   
   
   
           if(!editText.getText().toString().isEmpty()){
               EditTextValue = editText.getText().toString();
   
               try {
                   bitmap = TextToImageEncode(EditTextValue);
   
                   imageView.setImageBitmap(bitmap);
   
               } catch (WriterException e) {
                   e.printStackTrace();
               }
           }
           else{
               editText.requestFocus();
               Toast.makeText(MainActivity.this, "Please Enter Your Scanned Test" , Toast.LENGTH_LONG).show();
           }
   
         }
     });
   
   
   btnScan.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View view) {
   
           IntentIntegrator integrator = new IntentIntegrator(MainActivity.this);
           integrator.setDesiredBarcodeFormats(IntentIntegrator.ALL_CODE_TYPES);
           integrator.setPrompt("Scan");
           integrator.setCameraId(0);
           integrator.setBeepEnabled(false);
           integrator.setBarcodeImageEnabled(false);
           integrator.initiateScan();
   
        }
      });
       }
   
   
    Bitmap TextToImageEncode(String Value) throws WriterException {
      BitMatrix bitMatrix;
       try {
       bitMatrix = new MultiFormatWriter().encode(
               Value,
               BarcodeFormat.DATA_MATRIX.QR_CODE,
               QRcodeWidth, QRcodeWidth, null
       );
   
       } catch (IllegalArgumentException Illegalargumentexception) {
   
        return null;
      }
     int bitMatrixWidth = bitMatrix.getWidth();
   
     int bitMatrixHeight = bitMatrix.getHeight();
   
     int[] pixels = new int[bitMatrixWidth * bitMatrixHeight];
   
     for (int y = 0; y < bitMatrixHeight; y++) {
         int offset = y * bitMatrixWidth;
   
        for (int x = 0; x < bitMatrixWidth; x++) {
   
            pixels[offset + x] = bitMatrix.get(x, y) ?
                   getResources().getColor(R.color.QRCodeBlackColor):getResources().getColor(R.color.QRCodeWhiteColor);
         }
       }
       Bitmap bitmap = Bitmap.createBitmap(bitMatrixWidth, bitMatrixHeight, Bitmap.Config.ARGB_4444);
   
      bitmap.setPixels(pixels, 0, 350, 0, 0, bitMatrixWidth, bitMatrixHeight);
      return bitmap;
   }
   
   
   
   
     @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.e("Scan*******", "Cancelled scan");
   
        } else {
           Log.e("Scan", "Scanned");
   
           tv_qr_readTxt.setText(result.getContents());
           Toast.makeText(this, "Scanned: " + result.getContents(), Toast.LENGTH_LONG).show();
        }
     } else {
         // This is important, otherwise the result will not be passed to the fragment
       super.onActivityResult(requestCode, resultCode, data);
        }
      }
    }
   

5. You can download full source code from GitHub. GitHub link is : https://github.com/enamul95/QRCode

Zxing is an excellent library to perform Qr code scanning and generation. The following implementation uses Zxing library to scan the QR code image Don't forget to add following dependency in the build.gradle

implementation 'me.dm7.barcodescanner:zxing:1.9'

Code scanner activity:

    public class QrCodeScanner extends AppCompatActivity implements ZXingScannerView.ResultHandler {
        private ZXingScannerView mScannerView;

        @Override
        public void onCreate(Bundle state) {
            super.onCreate(state);
            // Programmatically initialize the scanner view
            mScannerView = new ZXingScannerView(this);
            // Set the scanner view as the content view
            setContentView(mScannerView);
        }

        @Override
        public void onResume() {
            super.onResume();
            // Register ourselves as a handler for scan results.
            mScannerView.setResultHandler(this);
            // Start camera on resume
            mScannerView.startCamera();
        }

        @Override
        public void onPause() {
            super.onPause();
            // Stop camera on pause
            mScannerView.stopCamera();
        }

        @Override
        public void handleResult(Result rawResult) {
            // Do something with the result here
            // Prints scan results
            Logger.verbose("result", rawResult.getText());
            // Prints the scan format (qrcode, pdf417 etc.)
            Logger.verbose("result", rawResult.getBarcodeFormat().toString());
            //If you would like to resume scanning, call this method below:
            //mScannerView.resumeCameraPreview(this);
            Intent intent = new Intent();
            intent.putExtra(AppConstants.KEY_QR_CODE, rawResult.getText());
            setResult(RESULT_OK, intent);
            finish();
        }
    }

Easy QR Code Library

A simple Android Easy QR Code Library. It is very easy to use, to use this library follow these steps.

For Gradle:

Step 1. Add it in your root build.gradle at the end of repositories:

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Step 2. Add the dependency:

dependencies {
        compile 'com.github.mrasif:easyqrlibrary:v1.0.0'
}

For Maven:

Step 1. Add the JitPack repository to your build file:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

Step 2. Add the dependency:

<dependency>
    <groupId>com.github.mrasif</groupId>
    <artifactId>easyqrlibrary</artifactId>
    <version>v1.0.0</version>
</dependency>

For SBT:

Step 1. Add the JitPack repository to your build.sbt file:

resolvers += "jitpack" at "https://jitpack.io"

Step 2. Add the dependency:

libraryDependencies += "com.github.mrasif" % "easyqrlibrary" % "v1.0.0"

For Leiningen:

Step 1. Add it in your project.clj at the end of repositories:

:repositories [["jitpack" "https://jitpack.io"]]

Step 2. Add the dependency:

:dependencies [[com.github.mrasif/easyqrlibrary "v1.0.0"]]

Add this in your layout xml file:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="20dp"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:id="@+id/tvData"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="No QR Data"/>
    <Button
        android:id="@+id/btnQRScan"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="QR Scan"/>

</LinearLayout>

Add this in your activity java files:

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    TextView tvData;
    Button btnQRScan;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvData=findViewById(R.id.tvData);
        btnQRScan=findViewById(R.id.btnQRScan);

        btnQRScan.setOnClickListener(this);
    }

    @Override
    public void onClick(View view){
        switch (view.getId()){
            case R.id.btnQRScan: {
                Intent intent=new Intent(MainActivity.this, QRScanner.class);
                startActivityForResult(intent, EasyQR.QR_SCANNER_REQUEST);
            } break;
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode){
            case EasyQR.QR_SCANNER_REQUEST: {
                if (resultCode==RESULT_OK){
                    tvData.setText(data.getStringExtra(EasyQR.DATA));
                }
            } break;
        }
    }
}

For customized scanner screen just add these lines when you start the scanner Activity.

Intent intent=new Intent(MainActivity.this, QRScanner.class);
intent.putExtra(EasyQR.IS_TOOLBAR_SHOW,true);
intent.putExtra(EasyQR.TOOLBAR_DRAWABLE_ID,R.drawable.ic_audiotrack_dark);
intent.putExtra(EasyQR.TOOLBAR_TEXT,"My QR");
intent.putExtra(EasyQR.TOOLBAR_BACKGROUND_COLOR,"#0588EE");
intent.putExtra(EasyQR.TOOLBAR_TEXT_COLOR,"#FFFFFF");
intent.putExtra(EasyQR.BACKGROUND_COLOR,"#000000");
intent.putExtra(EasyQR.CAMERA_MARGIN_LEFT,50);
intent.putExtra(EasyQR.CAMERA_MARGIN_TOP,50);
intent.putExtra(EasyQR.CAMERA_MARGIN_RIGHT,50);
intent.putExtra(EasyQR.CAMERA_MARGIN_BOTTOM,50);
startActivityForResult(intent, EasyQR.QR_SCANNER_REQUEST);

You are done. Ref. Link: https://mrasif.github.io/easyqrlibrary