为什么需要Context才能在Android中启动活动

Question

我了解什么是上下文，以及为什么需要它，但是为什么需要它来启动活动，为什么不能仅通过静态加载它们或调用其构造函数来完成它。

Answer 1

Why I cannot create and launch an activity like this: ActivityToLaunch activity = new ActivityToLaunch()

Short answer: because you don't own an Activity .

That is, an Activity is a special component managed by the Android framework, but that allows you to add your application logic in predefined methods like onCreate() , onResume() , etc, etc, that are called later by the system.

...

Imagine that you want to lunch a third party app from your application, for example the default file manager to allow the user to pick a file from the SD Card. Obviously you will not be able to do something like this:

  FileManager manager = new FileManager()

because the FileManager classes (or any other third-party app's classes) are not accessible in your application code, so... hopefully you can see already a limitation with this approach. That's why Android allows us to create an Intent where metadata about an Activity is given, pass it to startActivity(...) , and afterwards the system takes care of creating the started activity.

This was just one example, pretty sure there are other reasons why Android was designed like this.