Flutter 跳转到颤振碎片列表中的特定碎片
如何以编程方式跳转(或滚动)到条子列表中条子高度不同的特定条子?下面的代码将书籍文本加载到自定义滚动视图中,每个小部件都有一个章节。当按下操作按钮时,我希望视图跳到第3章,但什么也没有发生。我做错了什么Flutter 跳转到颤振碎片列表中的特定碎片,flutter,key,flutter-sliver,customscrollview,Flutter,Key,Flutter Sliver,Customscrollview,如何以编程方式跳转(或滚动)到条子列表中条子高度不同的特定条子?下面的代码将书籍文本加载到自定义滚动视图中,每个小部件都有一个章节。当按下操作按钮时,我希望视图跳到第3章,但什么也没有发生。我做错了什么 class BookPage extends StatefulWidget { BookPage({Key? key, this.title = "book"}) : super(key: key); String title; final _chapter
class BookPage extends StatefulWidget {
BookPage({Key? key, this.title = "book"}) : super(key: key);
String title;
final _chapter3key = new GlobalKey(debugLabel: "chap3key");
get chapter3Key => _chapter3key;
@override
_BookState createState() => _BookState();
}
class _BookState extends State<BookPage> {
ScrollController? scrollController = new ScrollController();
Map<int, String> chapterHTML = {};
String title = "";
final chapterCount=10;
void fetchText() async {
for (int i = 1; i <= 10; i++) {
chapterHTML[i] = await getChapterHtml(i);
}
setState(() {});
}
_BookState() {
fetchText();
}
Widget chapterSliver(int i) {
if (i==3) {
return Html(key: widget.chapter3Key, data: chapterHTML[i] ?? "", );
}
return Html(
data: chapterHTML[i] ?? "",
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: CustomScrollView(controller: scrollController, slivers: [
SliverList(
delegate: SliverChildBuilderDelegate ((BuildContext context, int index) {
if (index > chapterCount) return null;
return chapterSliver(index);
}// first sliver is empty (chapter 0!)
))
]),
floatingActionButton: FloatingActionButton(onPressed: () {
Scrollable.ensureVisible(widget.chapter3Key.currentContext);
})
);
}
}
class BookPage扩展StatefulWidget{
BookPage({Key?Key,this.title=“book”}):超级(Key:Key);
字符串标题;
最终的_chapter3key=新的GlobalKey(调试标签:“chapter3key”);
get chapter3Key=>\u chapter3Key;
@凌驾
_BookState createState()=>\u BookState();
}
类_BookState扩展状态{
ScrollController?ScrollController=新的ScrollController();
Map chapterHTML={};
字符串标题=”;
最终章节数=10;
void fetchText()异步{
for(int i=1;i chapterCount)返回null;
返回章条(索引);
}//第一条是空的(第0章!)
))
]),
浮动操作按钮:浮动操作按钮(按下时:(){
可滚动。可确保可修改(widget.chapter3Key.currentContext);
})
);
}
}
对于任何发现此问题的人,我已经找到了解决方案-使用scrollablePositionedList-