Flutter TextFormField controller into Text - flutter

Question

i have a problem :( I have a Detailform with Text Widget wehre im getting values from my DB.
I have one TextFormField with a controller, because i need to set the actual price, after i submitted it, the new value will updated in a TextValueField, but i want it to show on a normal Text widget.
i hope you can understand my problem. but here my code
TextField(
decoration: InputDecoration(labelText: 'actual cost'),
controller: _profitController,
keyboardType:
TextInputType.numberWithOptions(decimal: true),
onSubmitted: (val) {
double amount =
double.parse(selectedEntry.amount); // 1 value
double aktPrice =
double.parse(val); // 2 value from this textfield
double profit = aktPrice * amount; // calc
_endProfitController.text = profit.toString();
newProfit = profit;
},
),
TextFormField(
readOnly: true,
decoration: InputDecoration(labelText: "profit"),
controller:
_endProfitController, //this is getting updated with the controller
textAlign: TextAlign.left,
style: TextStyle(
fontSize: 20,
color: Colors.grey[700],
),
),
Text(
'test profit: ' +
_endProfitController.text.toString() + newProfit.toString() +
' €', // this is not getting updated, and newProfit says "Null"...
textAlign: TextAlign.left,
style: TextStyle(
fontSize: 20,
color: Colors.grey[700],
),
),
alright, how can i get the value in my Text Widget ?
I tried to setState in the onSubmitted but then the controller also isn't updating.
I tried to declare a new double newProfit but after submit it still gives me null back....
hope someone can help me :)
best regards
And thanks for your time :)

Answer 1

Its not updating because the widgets are already built when you change the text value of the controller if you are creating the form inside a stateful widget you can call setState() inside the onChanged so the value of the field updates the String you'll use to show the text, something like this.
TextFormField(
decoration: InputDecoration(labelText: "profit"),
controller:
_endProfitController, //this is getting updated with the controller
textAlign: TextAlign.left,
onChanged: (value) {
setState(() {
valueText = _endProfitController.text;
});
print(valueText);
},
style: TextStyle(
fontSize: 20,
color: Colors.grey[700],
),
),
Text(
'test profit: ' +
valueText +
' €', // this is not getting updated, and newProfit says "Null"...
style: TextStyle(
fontSize: 20,
color: Colors.grey[700],
),
),
The variable that will get the value of the controller's text has to be outside the build method
String valueText = '';
If you are not building this inside a stateful widget you can look at the Provider package to update a value that has no state