Deprecation warning

Please note that this is outdated documentation for an older release of the Scandit Barcode Scanner SDK.

We are deprecating the 5.x API on all platforms (except Linux). Release 5.19 in April 2021 will be our final. Applications running 5.x will continue to work, and we will continue to release critical bug fixes and security patches only, for one year. We encourage you to migrate to 6.x and take advantage of our latest / advanced features and improved performance.

You'll find the updated documentation at: Data Capture SDK Documentation for React Native

Define the scanning area

By default the Scandit Barcode Scanner searches the entire camera feed for barcodes. Under certain conditions it is helpful to restrict the area in which barcodes are recognized, for example if:

  • you only show a part of the barcode picker, codes that are not visible should generally not be recognized.
  • there are multiple barcodes close together and the user has to be able to select a specific one.

Restrict the scanning area

Restricting the scanning area is done through activeScanningAreaPortrait and activeScanningAreaLandscape on the settings object. The two properties allow you to have different scanning areas dependent on the device orientation. The area itself is specified as a rectangle with coordinates relative to the camera preview's size where the top-left corner is 0/0 and the bottom-right corner is 1/1. Setting Scandit.Rect(left:0.0, top:0.0, width:1.0, height:1.0) would set the scanning area to the entire camera preview.


The following sets the portrait's scanning area to 90% of the camera preview width and 10% of the preview height (centered).

this.settings = new ScanSettings();
this.settings.activeScanningAreaPortrait = new Rect(0.05, 0.45, 0.9, 0.1);

Adjust the viewfinder to match the scanning area

The viewFinder is the white rectangle that helps the user to aim for the barcode. If you restricted the scanning area, you most likely want to adjust the viewFinder's size accordingly. You can do this by setting the viewfinder dimension on the BarcodePicker. The coordinate system here is relative to the BarcodePicker's size.

To adjust the viewFinder's size to the previous example (90% width, 10% height):

picker.setViewfinderDimension(0.9, 0.1, 0.9, 0.1);

Alternatively, you can use the laser GUI style. It will display a laser line instead of the white rectangle. This style is useful when you want to scan in a small horizontal strip centered on the scanline in the center of the preview as it guides the user to place the code along the laser line.