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Public onCreate () or protected onCreate ()?

When reading the book "Hello, Android", I noticed that:

Each java file using the method onCreate(Bundle savedInstanceState)has a secure EXCEPT access key in the main activity of the program [, which has: public void onCreate(Bundle savedInstanceState)].

Why is the method onCreate publicin the main activity of the program, but protectedeverywhere?

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4 answers

onCeate () is protected to avoid calling it from an activity object.

MyActivity activity = new MyActivity();
activity.onCreate(args);  // which doesn't make sense because activity is not yet created

Since this method is only called when an activity is created, calling it yourself will most likely give you a nullpointerException , since this activity has not yet been created. S / O Message

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It can also be protected. There is nothing important or wise in this.

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There is no reason to make this method publicly available (but it does not affect anything). You should not call it manually anyway.

By the way, Intellij IDEA has a public activity template onCreate. This may be the reason this method is published in the book.

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