BarcodeDetector - Web APIs 编辑

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Secure context

This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The BarcodeDetector interface of the Barcode Detection API allows detection of linear and two dimensional barcodes in images.

Constructors

BarcodeDetector.BarcodeDetector()

Creates and returns a BarcodeDetector object, with optional barcodeDetectorOptions

Methods

detect()

Returns a Promise which fulfills with an array of detectedBarcode objects with the following properties:

• boundingBox: A DOMRectReadOnly, which returns the dimensions of a rectangle representing the extent of a detected barcode, aligned with the image.
• cornerPoints: The x and y co-ordinates of the four corner points of the detected barcode relative to the image, starting with the top left and working clockwise. This may not be square due to perspective distortions within the image.
• format: The detected barcode format. (For a full list of formats see the [landing page])
• rawValue: A String decoded from the barcode data.

getSupportedFormats()

Returns a Promise which fulfills with an Array of supported barcode format types.

Examples

Creating A Detector

This example creates a new barcode detector object, with specified supported formats and tests for browser compatibility.

// create new detector
var barcodeDetector = new BarcodeDetector({formats: ['code_39', 'codabar', 'ean_13']});

// check compatibility
if (barcodeDetector) {
  console.log('Barcode Detector supported!');
} else {
  console.log('Barcode Detector is not supported by this browser.');
}

Getting Supported Formats

The following example calls the getSupportFormat() static method and logs the results to the console.

// check supported types
BarcodeDetector.getSupportedFormats()
  .then(formats => {
    supportedFormats.forEach(format => console.log(format));
  });

Detect Barcodes

This example uses the detect() method to detect the barcodes within the given image. These are iterated over and the barcode data is logged to the console.

  barcodeDetector.detect(imageEl)
    .then(barcodes => {
      barcodes.forEach(barcode => console.log(barcode.rawData));
    }
    .catch(err => {
      console.log(err);
    })
  

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• barcodefaq.com: A website with information about different barcodes and examples of the different types.
• Accelerated Shape Detection in Images