SimpleCurrency | A simple application that converts currency

I'd like to be able to display the value entered in TextFormField with NumberFormat('###,##0.00', 'en_US').

There are no issues in the conversion, but I'm having issues displaying the value of formattedPrice in the TextFormField. I'd also like to set the default value of TextFormField as '0.00'. In my sample code below, the TextFormField restricts input to only have a single decimal symbol/separator and two decimal values.

I'm fine with .00 decimals not displayed when there are no decimals present in the TextFormField value during input, but I'd like the two decimal places format be placed when the value is entered.

I am using NumberFormat.simpleCurrency to format dollar amounts in my flutter app. It works great if trxns.contractPrice is not null. When it is null I get the following error: The getter 'isNegative' was called on null. Receiver: null Tried calling: isNegative

Here is the code snippet:

I have my app translated to different languages (https://pub.dev/packages/flutter_translate) and I also provide the option to select a specific currency (https://pub.dev/packages/country_currency_pickers):

first 2 options

When I select the currency I get this:

Now that everything is selected I need to update my currency and for that I can do:

I am trying to format the number according to selected currency without translating it. For example the