Why use the getbasecontext () method instead of this?

Q:ThisThe current context is often referenced. HoweverGetbasecontext ()To replaceThis. That is to say, useThisAn error is thrown.
Example:

Spinner spinner = (Spinner) findViewById(R.id.spinner);spinner.setAdapter(adapter);            spinner.setOnItemSelectedListener(new OnItemSelectedListener() {    @Override    public void onItemSelected(AdapterView<?>arg0, View arg1, int arg2, long arg3){       Toast.makeText(getBaseContext(),"SELECTED", Toast.LENGTH_SHORT).show(); //this line    }

WhenGetbasecontext ()ChangeThisThere will be errors.
Why must I useGetbasecontext ()Method, but cannot useThisWhat about it?

A:

1.Getapplicationcontext ()Method returns the context of the entire application lifecycle when the application is to be destroyed.
2.ThisThe application context returns the current context of the activity, which belongs to the activity. When it is destroyed, the activity is also destroyed. But in your case, it refers to the spinner instance, because weNitemselected (adapterview <?> Arg0, view arg1, int arg2, long arg3)Method. This method is from the spinner class, whileAdapterview. onitemselectedlistenerInterface to inherit this method.
3.Getbasecontext ()YesContextwrapper.

 

Reference: http://ask.csdn.net/questions/942

Why use the getbasecontext () method instead of this? (Transfer)