@diegoveloper的回答几乎可以，一个没有涉及的小问题是：它不会将单击Switch进一步传播到ExpansionTile，因此如果您单击外部开关，它会扩展，而单击Switch则不会执行任何操作。用IgnorePointer Package 它，并在扩展事件中设置switch的值。这是一个有点落后的逻辑，但工作得很好。

...
        return ExpansionTile(
          onExpansionChanged: _onExpansionChanged,
          // IgnorePointeer propogates touch down to tile
          trailing: IgnorePointer(
            child: Switch(
                value: isExpanded,
                onChanged: (_) {},
             ),
          ),
          title: Row(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: [
            Text(root.title),
          ]),
          children: root.children.map((entry) => EntryItem(entry)).toList(),
        );
...

• 我认为这将帮助你*initiallyExpanded：真实

itemBuilder: (context, index) {                        
                    return Column(
                      children: <Widget>[
                        Divider(
                          height: 17.0,
                          color: Colors.white,
                        ), 
                              ExpansionTile(  

                                    key: Key(index.toString()), //attention                                                                  
                                    initiallyExpanded : true,
                                    leading: Icon(Icons.person, size: 50.0, color: Colors.black,),
                                    title: Text('Faruk AYDIN ${index}',style: TextStyle(color: Color(0xFF09216B), fontSize: 17.0, fontWeight: FontWeight.bold)), 
                                    subtitle: Text('Software Engineer', style: TextStyle(color: Colors.black, fontSize: 13.0, fontWeight: FontWeight.bold),),
                                    children: <Widget>[                                       
                                      Padding(padding: EdgeInsets.all(25.0), 
                                                  child : Text('DETAİL ${index} \n' + 'It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using "Content here, content here", making it look like readable English.',)
                                                  ) 
                                    ],
                                    onExpansionChanged: ((newState){
                                        if(newState)
                                            setState(() {
                                              Duration(seconds:  20000);
                                              selected = index; 
                                            });
                                            else setState(() {
                                              selected = -1; 
                                            });        
                                    })
                                  ),
                             
                          ]
                        );

是的，这是可能的，我修改了你的代码一点：

class EntryItem extends StatefulWidget {
          const EntryItem(this.entry);
          final Entry entry;

          @override
          EntryItemState createState() {
            return new EntryItemState();
          }
        }

        class EntryItemState extends State<EntryItem> {
          var isExpanded = false;

          _onExpansionChanged(bool val) {
            setState(() {
              isExpanded = val;
            });
          }

          Widget _buildTiles(Entry root) {
            if (root.children.isEmpty)
              return Container(
                  child: Padding(
                      padding: const EdgeInsets.symmetric(
                        vertical: 8.0,
                        horizontal: 32.0,
                      ),
                      child: Row(
                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: [
                            Text(root.title),
                            Divider(
                              height: 10.0,
                            ),
                            root.question == 'text'
                                ? Container(
                                    width: 100.0,
                                    child: TextField(
                                        decoration: const InputDecoration(
                                            helperText: "question")),
                                  )
                                : Divider()
                          ])));
            return ExpansionTile(
              onExpansionChanged: _onExpansionChanged,
              trailing: Switch(
                value: isExpanded,
                onChanged: (_) {},
              ),
              //key: PageStorageKey<Entry>(root),
              title: Row(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: [
                Text(root.title),
              ]),
              children: root.children.map((entry) => EntryItem(entry)).toList(),
            );
          }

          @override
          Widget build(BuildContext context) {
            return _buildTiles(widget.entry);
          }
        }

基本上，我从Stateless改为Stateful，因为您需要处理Switch小部件的状态。
在ExpansionTile中有一个trailing属性，我在其中放置了Switch，以默认删除arrow小部件。
收听onExpansionChanged: _onExpansionChanged,，以更改交换机的状态。
最后将子组件构建为新的widget：

children: root.children.map((entry) => EntryItem(entry)).toList(),

**简答：**设置initiallyExpanded为true或false，相应的可以借助onExpansionChanged。但请记住initiallyExpanded仅适用于初始状态，因此应更改小部件的键以应用更改。现在要更改关键点，解决方法是：

ExpansionTile(
     key: PageStorageKey("${DateTime.now().millisecondsSinceEpoch}"),
     initiallyExpanded: ....
     onExpansionChanged: ....
     .
     .
     .
)

initiallyExpanded = true，这个答案是正确的，但是如果我们在ExpansionTile的子元素中有一个TextFiled，那么键盘会自动隐藏（bug）。所以我的解决方案是用Visibilitywidget和控件visibilty Package 孩子。初始声明**bool _expansionVisibility = false;**

ExpansionTile(
            onExpansionChanged: (changed) {
              setState(() {
                print("changed $changed");
                if (changed) {
                  _expansionVisibility = true;
                } else {
                  _expansionVisibility = false;
                }
              });
            },
            title: Text(
              "Change Password",
            ),
            children: <Widget>[
              Visibility(
                visible: _expansionVisibility,
                child: Container(),
              ),
            ],
          ),

现在有一个ExpansionTileController，它可以用编程方式关闭切片，如docs中所解释的。