Geek asks and answers

What is Bundle, View, Context?

Guys I watched a YouTube tutorial about an android that has 200 videos, but didn't explain what Bundle, View, and Context are.

1st question , what is a bundle?

Second question What is a bunch inside the onCreate method , where does this come from ? what's inside this package?

3rd question What is context? I found that Activity expands the context, is it right to say that Context is the activity itself? or context of this activity?

Fourth Question What is View? I found that TextView extends View and other widgets like Button EditText extend TextView, which means that they also extend the view. I also found that the syntax of Button, EditText, and other widgets is ...

TextView(Context);
Button(Context);
EditText(Context);

so my assumption is that "Context = Activity = Screen" and that "View = Button = TextView = EditText"

therefore in this example

public Example extends Activity{

    onCreate(){
        Button buttonObj = new Button(this):
    }
}

Button buttonObj = new Button(this);
" Example, Activity. " , View , , "?
, Button? , Activity.

5- , ?

add.setOnClickListener(new View.OnClickListener() {

    public void onClick(View v) {
        // TODO Auto-generated method stub

        //code here

    }
});

View.onclickListener()?? , , onClickListener??

?

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3

Bundle ~ a Bundle - . ( onCreate), Android ( !) . , HashMap? -, .

OnCreate Bundle ~ Android. , . , ( ?). , "" ( setExtra). onCreate, .

~ , . , , . , , , . , : . .

~ - , .

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OnCreate(): to onCreate() onDestroy(). "" onCreate() OnDestroy(). , , , onCreate(), OnDestroy(). OnCreate , . - , .. Bundle , , .

: - , View. . . (, ) , , , . , - , . , , . Android (), - , , , , ..

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, , , .

, .

Bundle - . , - , , .

- . ( ), . "this", . , , - . , , , .

- . , TextViews ( ), , , .

:

public Example extends Activity{
     onCreate(){
          Button buttonObj = new Button(this):
          }

} - , Activity. "" , onCreate. , "" , .

setOnClickListener . , onClick, - , , .

If you want to get into programming on Android, you really need to first read the FAQ on this site. You should only post answer questions, without requiring opinions such as a good book. Hundreds of people have already asked this question, and if you cannot perform a simple Google search, you may need a training program.

But I am very pleased that here are a few online tutorials that will help you get started and explain some things you are confused about:

http://developer.android.com/guide/index.html http://www.codeproject.com/Articles/102065/Android-A-beginner-s-guide

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