importance of Context in android

Question

Possible Duplicate:
What is Context in Android?

i read context in android current state of the application/object

   Intent intent=new Intent(this,SecondaryActivity.class);
   startActivity(intent);

in the place of this we can use getApplicationContext() but in an

@Override
public void onClick(View view) {

Toast.makeText(getApplicationContext(), "Hai",Toast.LENGTH_LONG).show();
}

we can't use this here i mean in getApplicationContext() why this also refers to the current object ,hence am confused about this and context help me to study this,an reference share me..

i already read that one ,but didnt get reason of that qn – J.K Aug 13 '12 at 13:39 — J.K, Aug 13 '12 at 13:39

Caner · Answer 1 · 2012-08-13T13:49:47.953

1

Activity is a sublcass of context so all Activity objects are also a Context:

android.content.Context
   ↳    android.content.ContextWrapper
       ↳    android.view.ContextThemeWrapper
           ↳    android.app.Activity

So if you can't use this than it means this is not an instance of an Context class or its subclass.

edited Aug 13 '12 at 13:49

answered Aug 13 '12 at 13:36

Caner

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score 1 · Accepted Answer · answered Aug 13 '12 at 13:41

1

When you pass this to method, you mean that this reference is an instance of Context, so if you are in Activity you can pass this instead of Context. But when you are in anonymous class:

button.setOnClickListener(new OnClickListener(){
     @Override
     public void onClick(){
         //here this is a reference to OnClickListener instance
     }

To pass Context in onClick method you can write

MyActivity.this

answered Aug 13 '12 at 13:41

No enclosing instance of the type MyActivity is accessible in scope :MyActivity.this – J.K Aug 13 '12 at 13:45
MyActivity should be replaced with your activity class name. – Aug 13 '12 at 13:45
oh i forgot that,youre right thanks – J.K Aug 13 '12 at 13:47

importance of Context in android

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