Skip to content

Instantly share code, notes, and snippets.

@adrianoluis
Created February 8, 2017 02:51
Embed
What would you like to do?
Simple utility class to create QR Code as Bitmap on Android using ZXing library
import android.graphics.Bitmap;
import android.graphics.Color;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
public class QRCodeUtil {
private QRCodeUtil() {}
public static Bitmap encodeAsBitmap(String source, int width, int height) {
BitMatrix result;
try {
result = new MultiFormatWriter().encode(source, BarcodeFormat.QR_CODE, width, height, null);
} catch (IllegalArgumentException | WriterException e) {
// Unsupported format
return null;
}
final int w = result.getWidth();
final int h = result.getHeight();
final int[] pixels = new int[w * h];
for (int y = 0; y < h; y++) {
final int offset = y * w;
for (int x = 0; x < w; x++) {
pixels[offset + x] = result.get(x, y) ? Color.BLACK : Color.WHITE;
}
}
final Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
bitmap.setPixels(pixels, 0, width, 0, 0, w, h);
return bitmap;
}
}
@vijaypatidar
Copy link

Thank you!

@yihongyuelan
Copy link

Kotlin version

import android.graphics.Bitmap
import android.graphics.Color
import com.google.zxing.BarcodeFormat
import com.google.zxing.MultiFormatWriter
import com.google.zxing.common.BitMatrix

fun encodeAsBitmap(source: String, width: Int, height: Int):Bitmap? {

    val result: BitMatrix = try {
        MultiFormatWriter().encode(source, BarcodeFormat.QR_CODE, width, height, null)
    } catch (e: Exception) {
        return null
    }

    val w = result.width
    val h = result.height
    val pixels = IntArray(w * h)

    for (y in 0 until h) {
        val offset = y * w
        for (x in 0 until w) {
            pixels[offset + x] = if (result[x, y]) Color.BLACK else Color.WHITE
        }
    }

    val bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)
    bitmap.setPixels(pixels, 0, width, 0, 0, w, h)

    return bitmap
}

@taimoorgit
Copy link

Do this to minimize the margins:

// Use a hintmap to minimize margins
HashMap hintMap = new HashMap();
hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.Q);
hintMap.put(EncodeHintType.MARGIN, 0);

result = new MultiFormatWriter().encode(source, BarcodeFormat.QR_CODE, width, height, hintMap);

Note that there will still be a white margin, since if you have a black background the QR code would be unreadable.

@Mubeyd
Copy link

Mubeyd commented Apr 22, 2022

It was very useful, Thanks. 👍

@PistonDragon
Copy link

Great!
HelpFULL!
I tried to get image from text, but the most of codes gave error.
Only your code SUCCESS.
thanks

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment