[android help] Why getApplicationContext() in constructor of Activity throws null pointer exception?

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	After some time spent bug hunting it turns out that : public class MainActivity extends BaseActivity { // BaseActivity extends Activity public MainActivity() { super(); getApplicationContext(); // NPE here } } Why ? Where is this documented ? Froyo asked Apr 14 at 22:03

	Wait for the end of onCreate to call this method. public class MainActivity extends BaseActivity { public onCreate(Bundle savedInstanceState) { super(savedInstanceState); getApplicationContext(); //activity has a context now } } answered Apr 14 at 22:11

Just to get a feeling of what's going on. Activity extends ContextThemeWrapper which extends ContextWrapper from whom Activity inherits getApplicationContext(). ContextWraper implements it as : @Override public Context getApplicationContext() { return mBase.getApplicationContext(); // mBase is a Context } The only public constructor of ContextWrapper is : public ContextWrapper(Context base) { mBase = base; } in ContextThemeWrapper we have : public ContextThemeWrapper() { super(null); } and since Activity does not define an explicit constructor the constructor above is called - mBase == null in Activity's constructor - boom. Links from 4.2.2_r1 answered 20 mins ago

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