当点击另一个 ExpansionTile 时关闭一个 ExpansionTile

Question

我有一个 ExpansionTile 列表，抽屉里有一个 ListTile 列表。我想要实现的是，当我按下一个 ExpansionTile 时，另一个 ExpansionTile 必须折叠。我被这个问题困扰了两天，找不到答案。有人知道如何以编程方式折叠 ExpansionTile 吗？

笔记：

我不想弄乱小部件的动画。

这是我的代码，

ListView.builder(
                itemCount: userList.length,
                shrinkWrap: true,
                itemBuilder: (BuildContext context, findex) {
                  return ExpansionTile(
                    key: Key(findex.toString()),
                    title: Text(userList[findex].parentdata[0].title,
                      style: TextStyle(fontSize: 15.0, fontWeight: FontWeight.bold,color: Colors.black),
                    ),
                    onExpansionChanged: (value) {
                    },
                    children: [
                      ListView.builder(
                        itemCount: userList[findex].document.length,
                        shrinkWrap: true,
                        itemBuilder: (BuildContext context, sindex) {
                          return ListTile(
                            title: Text(
                                userList[findex].document[sindex].title,
                              style: TextStyle(fontSize: 15.0, fontWeight: FontWeight.bold,color: Colors.black),
                            ),
                            onTap: () {
                              print(
                                  userList[findex].document[sindex].title);
                            },
                          );
                        },
                      ),
                    ],
                  );
                },
              ),

Answer 1

尝试下面的代码

声明一个 int 变量

int selectedTile = -1;

你的小部件

ListView.builder(
  key: Key(selectedTile.toString()),
  itemCount: 5,
  itemBuilder: (context, index) {
    return ExpansionTile(
      key: Key(index.toString()),
      initiallyExpanded: index == selectedTile,
      title: Text('ExpansionTile $index'),
      subtitle: Text('Trailing expansion arrow icon'),
      children: [
        ListTile(
          title: Text('This is tile number $index'),
        ),
      ],
      onExpansionChanged: ((newState) {
        if (newState)
          setState(() {
            selectedTile = index;
          });
        else
          setState(() {
            selectedTile = -1;
          });
      }),
    );
  },
);

Answer 2

尝试这个：

创建一个变量：int selected = -1;

和listview：

ListView.builder(
          itemCount: 10,
          shrinkWrap: true,
          itemBuilder: (BuildContext context, findex) {
            return ExpansionTile(
              initiallyExpanded: findex == selected,
              key: Key(selected.toString()),
              title: Text(userList[findex].parentdata[0].title,
                style: TextStyle(fontSize: 15.0, fontWeight: FontWeight.bold,color: Colors.black),
              ),
              onExpansionChanged: (newState) {
                setState(() {
                  selected = findex;
                });
              },
              children: [
                ListView.builder(
                  itemCount: 10,
                  shrinkWrap: true,
                  itemBuilder: (BuildContext context, sindex) {
                    return ListTile(
                      title: Text(
                        userList[findex].document[sindex].title,
                        style: TextStyle(fontSize: 15.0, fontWeight: FontWeight.bold,color: Colors.black),
                      ),
                      onTap: () {
                        print(userList[findex].document[sindex].title);
                      },
                    );
                  },
                ),
              ],
            );
          },
        ),