Issues with completed event and datamatrix barcode special characters

[Andy]

Hi everyone,

I got issues with the following constellation:

The application is a solution for logistics. There are cases where the user enters product codes by software keyboard or scans product labels with the built in barcode scan unit (Datalogic and Zebra Devices).

To cover both requirements I'm using the SfCombobox to show suggestions (works fine) or let the user scan a label. After the completed event, there is a web api request to find the requested product inside of the products database.

And here comes the problem:

When the user scans a datamatrix barcode, there is a chance of likely 50% that the completed event is firing "too early" after one of the barcode's special characters:

- In this example, the correct barcode should be 

"[)>[RS]06[GS]9N111234568408[GS]1TBTE4GAM[GS]D310822[GS]SST4102VGAARWAA[RS][EOT]".

- Inside the completed event, I compared the received string with the expected barcode and filled an error list if neccessary.

- As we can see, the completed event is firing randomly after one of the three special characters (RS, GS und EOT) and the scanned product code is incomplete:

And there are also cases where the received string is totally fine and equals the expected one.

Entrys work 100% accurate, but I need to cover both requirements in one control.

Please help :)

[Ruba Shanmugam]

Hi Maria,

We have validated your query and based on the provided details we don’t know the exact concept of scanning a data matrix barcode and how you assigning to the SfComboBox control. Can you share the below details,

1. How are you setting the text to SfComboBox on scanning
2. Where are you invoke the Completed event in SfComboBox

Please share the issue reproduced sample or code snippet with replication steps. This will be helpful to provide the solution earlier.

Regards,

Ruba Shanmugam

[Andy]

Thank you for the response.

The client device has a built in barcode scan unit. The scanned input is treated like keyboard input.

So when you are scanning a barcode, the scanned information appears inside the current focused control. Including all the special characters which are used as separators. And as you can see in the screenshot, one of these special characters raises randomly the completed event.

The scan unit also sends a line feed after the payload to trigger completed events. When using entry controls, this works 100% correct. 

However, something raises the completed event of the combobox too early and the list of failures suggests that the special characters are responsible. And it's really strange that it completes randomly after the first, second etc. special character.

The unicode representations of these special characters are:

\0x1D for GS

\0x1E for RS

\0x04 for EOT

And there is also a link where you find the official specifications, those types of barcodes are mandatory in some european countries for medical products e.

https://www.barcodefaq.com/2d/data-matrix/iso-iec-15434/

Thank you!

[Ruba Shanmugam]

Hi Maria,

We have prepared a sample with the SfComboBox and Completed event and we couldn’t able to replicate the reported issue. We have attached a sample for your reference. Please get it from the attachment.

Could you please share the issue replication sample it would be helpful for us to check on it and provide you solution at the earliest?

Regards,

Ruba Shanmugam

Attachment: ComboBoxSample_CompletedEvent_a510abe.zip

[Andy]

Hi,

thank you for the reply.

I can reproduce the same behaviour using the sample application when I'm scanning datamatrix barcodes with separator characters.

Is there a chance that we find a solution? SfCombobox is the only control that behaves like this and it would be very disappointing if we have to replace it by another control. 

[Ruba Shanmugam]

Hi Maria,

If possible can you please share your replication sample with us then only we proceed further on this.

Regards,

Ruba Shanmugam