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来自另一屏幕的颤振更新状态

setstate flutter

2

Ale · 技术社区 · 6 年前

ListView . 在第一个元素中,我显示变量的值 selectedObject .

ListTile 按下时,打开第二个屏幕。我想更新 选定对象 从第二个屏幕返回后的值。

result 致变量。

我想我得打电话给 setState 方法,但我不知道怎么做。

class _FilterTaskState extends State<FilterTask> {
List taskList;

String selectedObject = "initial value";

@override
Widget build(BuildContext context) {
return new Scaffold(
  appBar: _buildAppBar(context, "AppBar Title"),
  body: Center(
    child: new ListView(
      children: <Widget>[
         new ListTile(
          leading: new Icon(Icons.home, color: Colors.black),
          title: new Text("Selected Object", style: styleTitle),
          subtitle: new Text(selectedObject),
          trailing: new Icon(Icons.play_arrow, color: Colors.black),
          onTap: () => _navigateToFilterObject(context),
        ),

        ...

      ],
     )
   ),
  );
 }
}


 _navigateToFilterObject(BuildContext context) async {
    final result = await Navigator.push(context, 
    MaterialPageRoute(builder: (context) => FilterObject()),);

    /// I want to set the 'selectedObject' value
    /// selectedObject = result;

}

1 回复 | 直到 6 年前

1

4

diegoveloper 6 年前

关于你的 FilterObject 小部件在选择如下项时返回值:

        Navigator.of(context).pop(theValueYouWantToReceive);

result 变量:

final result = await Navigator.push(context, MaterialPageRoute(builder: (context) => FilterObject()),);

最终代码

     _navigateToFilterObject(BuildContext context) async {
            final result = await Navigator.push(context, 
            MaterialPageRoute(builder: (context) => FilterObject()),);
             //refresh the state of your Widget
                 setState(() {
              selectedObject = result;
            });

     }

_navigateToFilterObject 一定在你的身体里 _FilterTaskState

了解导航器弹出窗口: https://docs.flutter.io/flutter/widgets/Navigator/pop.html