小编Chi*_*iaz的帖子

带有图标的列表（IconData）需要很长时间才能加载，大约一分钟。以前，不存在这样的问题 - 列表在几秒钟内加载完毕。我尝试在 SSD 上重新安装 Flutter 和 Android Studio，但没有帮助。

如何解决这个问题？

Android Studio Arctic Fox | 2020.3.1 Patch 3
Build #AI-203.7717.56.2031.7784292, built on October 1, 2021
Runtime version: 11.0.10+0-b96-7249189 amd64
VM: OpenJDK 64-Bit Server VM by Oracle Corporation
Windows 10 10.0
GC: G1 Young Generation, G1 Old Generation
Memory: 1280M
Cores: 16
Registry: external.system.auto.import.disabled=true
Non-Bundled Plugins: com.intellij.marketplace, Dart, com.thoughtworks.gauge, org.jetbrains.kotlin, io.flutter, org.intellij.plugins.markdown

Dart: 203.8452
Flutter: 62.0.1

如何重置或选择 DropdownButtonFormField 中的第一个值？这里的How to Reset value in Flutter DropdownButtonFormField的答案已经过时，不适合较新的flutter版本。

下拉按钮表单字段：

final etSkillScore1Key = GlobalKey<FormState>();
...
DropdownButtonFormField(
          key: etSkillScore1Key,
          decoration: const InputDecoration(labelText: 'Select value'),
          onChanged: (val) async {
            setState(() {
              etSkillScore1 = val as int;
            });

            FocusScope.of(context).requestFocus(FocusNode());
          },
          value: etSkillScore1,
          items: priorities2.map((db.Priority priorities) {
            return DropdownMenuItem(
              child: Text(priorities.name),
              value: priorities.value,
            );
          }).toList(),
        ),

重置值按钮：

IconButton(
              onPressed: () {
                //ERORR: Null check operator used on a null value
                etSkillScore1Key.currentState!.reset();
              },
              icon: Icon(
                Icons.close,
              ))

错误：

======== Exception caught by gesture …

我需要从共享首选项中获取一个存储值并将其放入文本小部件中。如果没有未来的建造者，我该如何做到这一点？

_currPage() async {
  SharedPreferences prefs = await SharedPreferences.getInstance();
  int page = prefs.getInt('currPage') ?? 0;
  return page;
}

class _AllTasksPageState extends State<AllTasksPage> {
  @override
  Widget build(BuildContext context) {
  ...
  Text(_currPage()); //not working
  ...
  }
}