flutter - 按下按钮时颤动更改文本

Question

伙计们，我会尝试在单击按钮时更改文本...

我的代码：

         bool pressGeoON = false;
         bool cmbscritta = false;
           RaisedButton(
                  shape: new RoundedRectangleBorder(
                      borderRadius: new BorderRadius.circular(18.0),
                      side: BorderSide(color: Colors.red)),
                  color: pressGeoON ? Colors.blue: Colors.red,
                  textColor: Colors.white,
                  child:  cmbscritta ? Text("GeoOn"): Text("GeoOFF"),
                  //    style: TextStyle(fontSize: 14)

                  onPressed: () {
                    setState(() => pressGeoON = !pressGeoON);
                    setState(() => cmbscritta = !cmbscritta);
                  },
                )

dart Analisys 没有任何建议，但不起作用...帮助！

标签： flutterdart

Answer 1

你的班级必须是有状态的才能改变活动状态

变量也必须全局声明

class MyClass extends StatefulWidget {
  @override
  _MyClassState createState() => _MyClassState();
}

class _MyClassState extends State<MyClass> {
  bool pressGeoON = false;
  bool cmbscritta = false;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: RaisedButton(
          shape: new RoundedRectangleBorder(
              borderRadius: new BorderRadius.circular(18.0),
              side: BorderSide(color: Colors.red)),
          color: pressGeoON ? Colors.blue : Colors.red,
          textColor: Colors.white,
          child: cmbscritta ? Text("GeoOn") : Text("GeoOFF"),
          //    style: TextStyle(fontSize: 14)
            onPressed: () {
              setState(() {
                pressGeoON = !pressGeoON;
                cmbscritta = !cmbscritta;
              });
            }
        ),
      ),
    );
  }
}