使用按鈕 flutter 不更新 BottomSheet 值

Question

我有一個底部表，其中包含一組按鈕。 我使用按鈕更改 pinString 的值和顯示pinString的pinString 。 單擊按鈕時，文本的值不會更新。 如何解決這個問題

  showNumberPad(BuildContext context) {
    showModalBottomSheet(
      context: context,
      builder: (context) {
        return StatefulBuilder(builder: (context, setState) {
          return Container(
            height: 550.0,
            child: Column(
              children: <Widget>[
                Text(
                  "$pinString",
                ),
                KeyboardNumber(
                  n: 1,
                  onPressed: () {
                     pinIndexSetup("1");
                     setState1() {
                       pinString = "New Pin";
                     }
                  },
                ),
              ],
            ),
          );
        });
      },
    );
  }

KeyboardNumber 是一個自定義的有狀態小部件，我想將 onPressed 作為參數傳遞。 鍵盤編號代碼：

class KeyboardNumber extends StatefulWidget {
  final int n;
  final onPressed;

  const KeyboardNumber({Key key, this.n, this.onPressed}) : super(key: key);

  @override
  _KeyboardNumberState createState() => _KeyboardNumberState();
}

class _KeyboardNumberState extends State<KeyboardNumber> {
  @override
  Widget build(BuildContext context) {
    return Container(
      width: 60.0,
      height: 60.0,
      decoration: BoxDecoration(
        color: teal2,
        borderRadius: BorderRadius.all(
          Radius.circular(10),
        ),
      ),
      alignment: Alignment.center,
      child: FlatButton(
        padding: EdgeInsets.all(8.0),
        onPressed: widget.onPressed,
        height: 90.0,
        child: Text(
          "${widget.n}",
          textAlign: TextAlign.center,
          style: TextStyle(
            fontSize: 16,
            color: Colors.white,
            fontWeight: FontWeight.bold,
          ),
        ),
      ),
    );
  }
}

Answer 1

您在另一個state 中定義 pinString 並在bottomeSheet state中更改它，您必須在此行中定義它：

    showModalBottomSheet(
      context: context,
      builder: (context) {
        String pinString = 'hi';
        return StatefulBuilder(builder: (BuildContext context, StateSetter setState){
          return Container(
            height: 550.0,
            child: Column(
              children: <Widget>[
                Text(
                  "$pinString",
                ),
                FlatButton(
                  child: Text("Update"),
                  onPressed: () {
                    setState(() => pinString = 'new');
                  },
                ),
              ],
            ),
          );
        });
      },
    );
  }

Answer 2

請注意，新的setState將覆蓋您的主小部件setState但確保您可以重命名它，以便您能夠設置父小部件的 state 和模態的

這是更新的代碼。

showNumberPad(BuildContext context) {
    showModalBottomSheet(
      context: context,
      builder: (context) {
        return StatefulBuilder(builder: (context, SetState1) {
          return Container(
            height: 550.0,
            child: Column(
              children: <Widget>[
                Text(
                  "$pinString",
                ),
                FlatButton(
                  child: Text("Update"),
                  onPressed: () {
                    SetState1(() {
                      pinString = "New Pin";
                    });
                  },
                ),
              ],
            ),
          );
        });
      },
    );
  }