英文:
How to update a StateProvider when disposing a widget?
问题
Code:
@override
void dispose() {
// 重置任何请求映射的初始状态
ref.read(fsdMapStateProvider.notifier).state = null;
super.dispose();
}
Error:
════════════════════════════════════ 错误信息 ════════════════════════════════════
在构建小部件树完成时，抛出了以下断言：
查找已停用小部件的祖先是不安全的。
此时，小部件元素树的状态不再稳定。
为了安全地在dispose()方法中引用小部件的祖先，请在小部件的didChangeDependencies()方法中调用dependOnInheritedWidgetOfExactType()来保存对祖先的引用。
英文:
If I try and update the stateProvider by overriding the widgets dispose method I get an exception as shown below. Any idea how to update the state, so that the next time this widget is rebuilt it's using the state of null:
Code:
@override
void dispose() {
//reset any request map initial bounds
ref.read(fsdMapStateProvider.notifier).state = null;
super.dispose();
}
Error:
════════ Exception caught by widgets library ═══════════════════════════════════
The following assertion was thrown while finalizing the widget tree:
Looking up a deactivated widget's ancestor is unsafe.
At this point the state of the widget's element tree is no longer stable.
To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method.
答案1
得分: 2
尝试使用deactivate方法而不是dispose。
此方法在小部件从小部件树中移除之前调用，也就是在小部件完全被处理之前调用。
@override
void deactivate() {
// 重置任何请求映射的初始边界
ref.read(fsdMapStateProvider.notifier).state = null;
super.deactivate();
}
文档链接：deactivate方法
英文:
Try the deactivate method rather than the dispose.
This method gets called before the widget is removed from the widget tree, meaning just before the widget gets fully disposed.
@override
void deactivate() {
//reset any request map initial bounds
ref.read(fsdMapStateProvider.notifier).state = null;
super.deactivate();
}
Docs: deactivate method
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