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QR/Barcode Scanning

What is a Code Scanner?​

A Code Scanner is a separate Camera output (just like photo or video) that can detect a variety of machine-readable codes, such as:

  • QR: Square QR codes
  • Aztec: Square Aztec codes
  • Data Matrix: Square Data Matrix codes
  • Barcode (EAN): EAN-13 or EAN-8 Barcodes
  • Barcode (Code): Code-128, Code-39 or Code-93 Barcodes
  • Barcode (other): Codabar, ITF-14, UPC-E or PDF-417 Barcodes

Setup​

On iOS, the Code Scanner uses the platform-native APIs and can be used out of the box.

On Android, the MLKit Vision Barcode Scanning API will be used, and the model (2.2MB) needs to be downloaded first.

To download the model when the user installs your app, add this to your AndroidManifest.xml file:

<application ...>
...
<meta-data
android:name="com.google.mlkit.vision.DEPENDENCIES"
android:value="barcode" />
</application>

Usage​

To use a codescanner, simply create a CodeScanner and pass it to the <Camera>:

const codeScanner = useCodeScanner({
codeTypes: ['qr', 'ean-13'],
onCodeScanned: (codes) => {
console.log(`Scanned ${codes.length} codes!`)
}
})

return <Camera {...props} codeScanner={codeScanner} />

The result of this will automatically be memoized.

Separate Output​

Since the Code Scanner is a separate camera output (just like photo or video), it cannot be attached simultaneously with photo and video enabled. You need to disable either photo, video, or the codeScanner.

Code result​

The Code Scanner will call your onCodeScanned callback with all detected codes (Code), including their decoded string value, and their coordinates on the screen relative to the Preview.


🚀 Next section: Frame Processors​