如何将参数从一个选项卡传递到另一个选项卡？

Question

My application has two tabs. One contains the Chapter and second tab contains the Lessons. The number of lessons on second tab is dynamic and depends on from which Chapter it is building. I could move from First Tab to Second using the DefaultTabController.of(context).animateTo(1) But how can I pass the chapter index to second tab like the arguments in Navigator.push ?

Answer 1

A possible solution could arrive with the provider package. Do not place it at the top of your widget tree if you don't need it, you'll avoid potential useless rebuilds.

Probably you want to do this:

class Data {
  String something;
}

And then at some point in your widget tree, above the page with the tabs, you use:

Provider(
  create: (_) => Data(),
  child: YourWidgetWithTabs()
)

Childs will be able to call Provider.of<Data>(context) to get the data. It's usually better to use Consumer which gives you more control on rebuilds and consequently it improves performance.

You will crate a proper Data class (not like mine, it just gives the idea).

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The general point is to have a "data holder" at the top of the tree that you use to read/write data. If you also need to listen to changes made to the data source, use ChangeNotifierProvider .