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Accepted
Lucas Tomic
Asked: 2022-07-22 11:18:44 +0800 CST 2022-07-22 11:18:44 +0800 CST

Why is this Widget not redrawing correctly?

  • 772

I have a form and I want it to redraw when I press the submit button and go from saying "Enter" to "Please wait".

For this I use a StatefullWidgetwith the property isLoadingthat changes when the button is pressed with a setStatefrom false to true. The button's text is rendered based on the value of the boolean isLoading, however pressing the button does not re-draw it correctly and still shows the text "Enter".

    class _LoginForm extends StatefulWidget {

  @override
  State<_LoginForm> createState() => _LoginFormState();
}

class _LoginFormState extends State<_LoginForm> {
  @override
  Widget build(BuildContext context) {

    bool isLoading = false;

    return Container(
      child: Form(
        child: Column(
          children: [
            TextFormField(
            ),

//Botón en cuestion
            MaterialButton(
              onPressed:(){
              setState(() {
                isLoading=true; //setState donde debería redibuujarse el botón
              });
              } ,
              child:Container(
                child:Text(isLoading ? 'Espere' : 'Ingresar', style:TextStyle(color:Colors.white)),//Texto que se renderiza según isLoading, pero que no se redibuja como debería
              ),
              )
          ],
        ),
      ),
    );
  }
}
flutter

1 Answers

  1. Best Answer

    You are making a mistake, the variable isLoadingmust go outside the method build, put it outside the method buildand it will work correctly.

        class _LoginFormState extends State<_LoginForm> {
     bool isLoading = false;
    @override
    Widget build(BuildContext context) {
    return Container(
      child: Form(
        child: Column(
          children: [
            TextFormField(
            ),
            //Botón en cuestion
            MaterialButton(
              onPressed:(){
              setState(() {
                isLoading=true; 
              });
              } ,
              child:Container(
                child:Text(isLoading ? 'Espere' : 'Ingresar', 
             style:TextStyle(color:Colors.white)),
              ),
              )
          ],
        ),
      ),
    );
  }
}
    • 4