showDialog(
        context: context,
        builder: (BuildContext context) {
          return AlertDialog(
            content: Container(
              width: double.maxFinite,
              height: 500,
              child: ListView(
                padding: EdgeInsets.zero,
                scrollDirection: Axis.vertical,
                children: [
                  Theme(
                    data: ThemeData(
                      checkboxTheme: CheckboxThemeData(
                        shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(25),
                        ),
                      ),
                      unselectedWidgetColor: Color(0xFF95A1AC),
                    ),
                    child: CheckboxListTile(
                      value: checkboxListTileValue9 ??= false,
                      onChanged: (newValue) =>
                          setState(() => checkboxListTileValue9 = newValue!),
                      title: Text(
                        'Wafer Chuck',
                      ),
                      subtitle: Text(
                        '14.400,00 €',
                      ),
                      tileColor: Color(0xFFF5F5F5),
                      activeColor: Colors.black,
                      dense: false,
                      controlAffinity: ListTileControlAffinity.trailing,
                    ),
                  ),
                ],
              ),
            ),
          );
        });
  }

above is my code. I want to make a selection with the checkboxlist I added in the AlertDialog, but my selection appears when the alertdialog is closed. In other words, there is no change when Alertdialog is open. How can I fix this.

CodePudding user response：

Wrap your AlertDialog with StatefulBuilder and use its setState.

showDialog(
  context: context,
  builder: (BuildContext context) {
    return StatefulBuilder(
      builder: (context, setState) =>  
        AlertDialog(
        content: Container(
          width: double.maxFinite,
          height: 500,
          child: ListView(
            padding: EdgeInsets.zero,
            scrollDirection: Axis.vertical,
            children: [
              Theme(
                data: ThemeData(
                  checkboxTheme: CheckboxThemeData(
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(25),
                    ),
                  ),
                  unselectedWidgetColor: Color(0xFF95A1AC),
                ),
                child: CheckboxListTile(
                  value: checkboxListTileValue9 ??= false,
                  onChanged: (newValue) =>
                      setState(() => checkboxListTileValue9 = newValue!),
                  title: Text(
                    'Wafer Chuck',
                  ),
                  subtitle: Text(
                    '14.400,00 €',
                  ),
                  tileColor: Color(0xFFF5F5F5),
                  activeColor: Colors.black,
                  dense: false,
                  controlAffinity: ListTileControlAffinity.trailing,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  });