Hi Rei,
Thank you for using Syncfusion products.
We have prepared a workaround sample for ignoring the NumberGroupSeparator in SfNumericTextBox. In the sample, we have set the Culture.NumberFormat.NumberGroupSeparator to empty string, so that comma will be ignored in any case. Text entered in SfNumericTextBox will be parsed to value when focus change events are fired. So we couldn’t ignore comma when SfNumericTextBox is focused and include comma when SfNumericTextBox is lost focus in sample. Also setting FormatString property will not ignore comma in SfNumericTextBox when focused. Please find the sample and online documentation for FormatString property in following link,
http://help.syncfusion.com/UG/winrt/documents/numberformatting.htmSample:
NumericTextBox_FormatString.zipPlease let us know if you need further assistance on this.
Regards,
Jessie