How To Generate QR Code In Android

Introduction: 

In this article, we will learn how to generate QR Code in Android. Quick Response Code (QR Code in short) is a 2-Dimensional matrix type barcode used to store data. It is more popular because of its storage capacity and fast readability.

Zxing & QR Generator Library:

Zebra Crossing (Zxing) is an awesome library used to generate and read QR codes in mobile apps. But it is bigger in size. So, we have to go for another one, QR Generator which is a tiny, open source library. In this article, we will learn how to create & save the QR Code in Android programmatically.

Steps:

I have split this part into 4 steps as in the following.

1. Creating a New Project with Empty Activity.
2. Setting up the library and manifest.
3. Generating QR Code.
4. Saving QR Code.

Step 1 - Creating New Project with Empty Activity

1. Open Android Studio and Select create a new project.
2. Name the project as per your wish and select an Empty activity.
   
   
3. Click “finish” button to create a new project in Android Studio.

Step 2 - Setting up the library and manifest

1. Open App level gradle file and import the library.

   implementation 'androidmads.library.qrgenearator:QRGenearator:1.0.3'

2. The, click “Sync Now”.
3. Then, open your Manifest file and add the following permissions. It is used to save QR Code to file storage.

   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

4. We need to handle runtime permissions from Android Version 6.0.

Step 3 - Generating QR Code

In this step, we will learn how to generate QR Code in Android. Open your MainActivity.java file and add the following lines.

QRGEncoder qrgEncoder = new QRGEncoder(inputValue, null, QRGContents.Type.TEXT, smallerDimension);

- Here, inputValue is an input to be converted to QR Code.
- Input Type also can be specified while initializing the library.
- We can specify the dimensions also.
Then, add the following lines to create QR Code and encode that into Bitmap Format.

try {  
  // Getting QR-Code as Bitmap  
  bitmap = qrgEncoder.encodeAsBitmap();  
  // Setting Bitmap to ImageView  
  qrImage.setImageBitmap(bitmap);  
} catch (WriterException e) {  
  Log.v(TAG, e.toString());  
}

qrImage is an ImageView used to preview the generated QR code bitmap.

Step 4 - Saving QR Code

QR Generator has an option to save the generated QR Code Bitmap to storage using the following lines.

// Save with location, value, bitmap returned and type of Image(JPG/PNG).  
QRGSaver.save(savePath, edtValue.getText().toString().trim(), bitmap, QRGContents.ImageType.IMAGE_JPEG);

We can save QR Code in PNG & JPG format also. We have to handle runtime permissions from Android version 6.0.

Full Code

You can find the full code implementation here.

public class MainActivity extends AppCompatActivity {  
  
    String TAG = "GenerateQRCode";  
    EditText edtValue;  
    ImageView qrImage;  
    Button start, save;  
    String inputValue;  
    String savePath = Environment.getExternalStorageDirectory().getPath() + "/QRCode/";  
    Bitmap bitmap;  
    QRGEncoder qrgEncoder;  
  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
  
        qrImage = (ImageView) findViewById(R.id.QR_Image);  
        edtValue = (EditText) findViewById(R.id.edt_value);  
        start = (Button) findViewById(R.id.start);  
        save = (Button) findViewById(R.id.save);  
  
        start.setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View view) {  
                inputValue = edtValue.getText().toString().trim();  
                if (inputValue.length() > 0) {  
                    WindowManager manager = (WindowManager) getSystemService(WINDOW_SERVICE);  
                    Display display = manager.getDefaultDisplay();  
                    Point point = new Point();  
                    display.getSize(point);  
                    int width = point.x;  
                    int height = point.y;  
                    int smallerDimension = width < height ? width : height;  
                    smallerDimension = smallerDimension * 3 / 4;  
  
                    qrgEncoder = new QRGEncoder(  
                            inputValue, null,  
                            QRGContents.Type.TEXT,  
                            smallerDimension);  
                    try {  
                        bitmap = qrgEncoder.encodeAsBitmap();  
                        qrImage.setImageBitmap(bitmap);  
                    } catch (WriterException e) {  
                        Log.v(TAG, e.toString());  
                    }  
                } else {  
                    edtValue.setError("Required");  
                }  
            }  
        });  
  
        save.setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View v) {  
                boolean save;  
                String result;  
                try {  
                    save = QRGSaver.save(savePath, edtValue.getText().toString().trim(), bitmap, QRGContents.ImageType.IMAGE_JPEG);  
                    result = save ? "Image Saved" : "Image Not Saved";  
                    Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG).show();  
                } catch (Exception e) {  
                    e.printStackTrace();  
                }  
            }  
        });  
  
    }  
}

Download Code

You can download the full source code of the article in GitHub. If you like this article, do star the repo in GitHub.