Provider.of(context，listen:false)是否等效于context.read()? [英] Is Provider.of(context, listen: false) equivalent to context.read()?

问题描述

// Are these the same?
final model = Provider.of<Model>(context, listen: false); 
final model = context.read<Model>(); 

// Are these the same?
final model = Provider.of<Model>(context);
final model = context.watch<Model>();

它们是相同的还是不是?如果是，那么为什么在Provider.of()起作用的情况下在build()方法中使用read时出现此错误?

Are they the same or aren't they? If they are, then why do I get this error when I use read inside the build() method, while Provider.of() works?

试图在提供程序的build方法或update回调中使用context.read<Model>.

Tried to use context.read<Model> inside either a build method or the update callback of a provider.

推荐答案

嗯，它们不一样.

您不应在build方法内使用read.而是坚持使用古老的金色图案:

You shouldn't use read inside the build method. Instead stick to the old is gold pattern:

final model = Provider.of<Model>(context, listen: false); 

read用于要在回调中使用上述模式的情况，例如，当按下按钮时，可以说它们都在执行相同的操作.

read is used when you want to use the above pattern in a callback, for instance, when a button is pressed, then we can say they both are performing the same action.

onPressed: () {
  final model = context.read<Model>(); // recommended
  final model = Provider.of<Model>(context, listen: false); // works too
}

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