我正在尝试使用Sliver来实现可折叠的列表头。当我将小部件从普通窗口小部件更改为小窗口窗口小部件时,我经常会出现这样的错误:
I/flutter ( 3141): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 3141): The following assertion was thrown building NotificationListener<ScrollNotification>():
I/f
我在构建navigationDrawer时遇到了错误,tootlip小部件需要materialApp作为祖先。
错误是这样说的:
I/flutter ( 5780): _TooltipState#bc79e(ticker inactive)):
I/flutter ( 5780): No Overlay widget found.
I/flutter ( 5780): Tooltip widgets require an Overlay widget ancestor for correct operation.
I/flutter ( 5780): The most common way t
在树构建逻辑中添加条件构造会导致挂载/卸载小部件。如果小部件内部带有控制器,这反过来又会导致恼人的动画问题。
您如何告诉Flutter阻止widget状态被释放,而是在树的另一部分中搜索它?
build(BuildContext context) {
var value = controller.value;
/// Let's avoid blinking at high opacity, save CPU at the same time
/// commenting this line will result in smooth animation
/// w
我有一个小部件,当点击时,保存一个ID号,覆盖1000ms的CircularProgressIndicator,然后弹出进度指示器,并将用户路由到另一个页面。
这个带有ProgressIndicator和计时器的位是新的,它破坏了我的单元测试,现在给出了以下错误:
The following assertion was thrown running a test:
'package:flutter_test/src/binding.dart': Failed assertion: line 574 pos 12: '() {
'A Timer is