如何在flutter中更改showDateRangePicker（）或showDateRangePicker（）的TextStyle

Question

要在Flutter中更改helpText中showDateRangePicker()的文本样式。

任何人都可以帮忙。

---

  buildMaterialDatePicker({BuildContext context, SearchVM model}) 
   async {
    final DateTimeRange picked = await showDateRangePicker(
      context: context,
      firstDate: initialDate,
      helpText: 'Select a Date or Date-Range',
      fieldStartHintText: 'Start Booking date',
      fieldEndHintText: 'End Booking date',
      currentDate: initialDate,
      lastDate: DateTime(2020, initialDate.month + 1, 
      initialDate.day),
      builder: (BuildContext context, Widget child) {
        return Theme(
          data: ThemeData.dark().copyWith(
            colorScheme: ColorScheme.dark(
              primary: Colors.greenAccent,
              onPrimary: oppColor,
              surface: Colors.greenAccent,
              onSurface: oppColor,
            ),
            dialogBackgroundColor: mainColor,
          ),
          child: child,
        );
      },
    );
  }

Answer 1

要更改颜色，字体等，必须将元素包装到主题中：

Widget returnRangePicker(BuildContext context) {
    return Theme(
      data: Theme.of(context).copyWith(
          accentColor: Colors.green,
          primaryColor: Colors.blue,
          buttonTheme: ButtonThemeData(
              highlightColor: Colors.green,
              buttonColor: Colors.green,
              colorScheme: Theme.of(context).colorScheme.copyWith(
                  secondary: epapGreen,
                  background: Colors.white,
                  primary: Colors.green,
                  primaryVariant: Colors.green,
                  brightness: Brightness.dark,
                  onBackground: Colors.green),
              textTheme: ButtonTextTheme.accent)),
      child: Builder(
        builder: (context) => FlatButton(
          onPressed: () async {
            final List<DateTime> picked = await DateRangePicker.showDatePicker(
                context: context,
                initialFirstDate: DateTime.now(),
                initialLastDate:
                    DateTime.now()).add(Duration(days: 7),
                firstDate: DateTime(2015),
                lastDate: DateTime(2020));
            if (picked != null && picked.length == 2) {
              print(picked);
            }
          },
          child: Text(
            "Choose range",
            style: TextStyle(color: Colors.green),
          ),
        ),
      ),
    );
  }

有关更多信息，您可以查看docs。或检查此link

Answer 2

因此，根据abbas jafary的答案。 我深入研究了showDateRangePicker()的文档（您可以使用Ctrl+ Right-Clicking来进行查找），并发现它用于该texstTheme的{​​{1}}。

Text

因此，然后我用 Text( helpText, style: textTheme.overline.apply( color: headerForeground,), ), 包装了窗口小部件并更新了Theme字段。

textTheme