Flutter语言 - 如何在PageView中重置当前页面索引(刷卡后)?

Question

我有一个简单的PageView.builder:

@override
void initState() {
super.initState();
_pageController =
PageController(initialPage: 0, keepPage: true, viewportFraction: 1);
_pageController.addListener(() {
setState(() {
_activeImageIndex = _pageController.page!.toInt();
});
});
}

……

child: PageView.builder(
scrollDirection: Axis.vertical,
controller: _pageController,
itemCount: lstUserImages.length,
onPageChanged: (page) {
setState(() {
_activeImageIndex = page;
});
},
itemBuilder: (context, index) {
return GestureDetector(
child: Image.asset(
lstUserImages[index],
fit: BoxFit.cover,
),
);
}),

它工作得很好，除了当我刷卡时，它不会将页面索引重置为0(对于下一张卡)。因此，如果对于一张卡，我正在查看第三张图像(index = 2)，那么在我刷那张卡之后，下一张卡将加载显示的第三张图像。

我有onswipeccomplete可用:

swipeCompleteCallback:
(CardSwipeOrientation orientation, int index) {

setState(() {
//WHAT DO I DO HERE SO THAT THE PAGE INDEX IS SET TO ZERO AGAIN..??

//isCardChanged = true;
//_pageController.jumpToPage(0);
_pageController = PageController(
initialPage: 0, keepPage: true, viewportFraction: 1);
});
},

Answer 1

只需将TinderSwapCard内容更新为

TinderSwapCard(
orientation: AmassOrientation.BOTTOM,
totalNum: 3,
stackNum: 3,
swipeEdge: 4.0,
maxWidth: MediaQuery.of(context).size.width * 0.9,
maxHeight: MediaQuery.of(context).size.width * 0.9,
minWidth: MediaQuery.of(context).size.width * 0.8,
minHeight: MediaQuery.of(context).size.width * 0.8,
cardBuilder: (context, index) {
/// to reset the [_pageController] to a new value
/// preventing the "multiple PageViews are attached to the same PageController" from appears
_pageController = PageController(
initialPage: 0, keepPage: true, viewportFraction: 1);
return PageView.builder(
scrollDirection: Axis.vertical,
controller: _pageController,
itemCount: lstUserImages.length,
onPageChanged: (page) => setState(() => _activeImageIndex = page),
itemBuilder: (context, index) {
return Image.network(
lstUserImages[index],
fit: BoxFit.cover,
);
});
},
cardController: cardController,
swipeCompleteCallback: (CardSwipeOrientation orientation, int index) {
/// at [TinderSwapCard] swiping ensure the [_pageController] scrolled to the zero index
setState(() {
_pageController.jumpToPage(0);
});
},
)