将Intent传递给函数将引发NullPointerException

Question

In an Android I would like to pass an Intent Object to a function, but consistently get a NullPointerException.

I could not find any source citing that this is not possible.

basically I have this:

 public Intent intent;

    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    intent = getIntent();
    int check = elsewhere.chk_intent(intent); //<=THROWS ERROR

     }

chk_intent() performs some functions on data transmitted with the intent, especieally if some extra fields are present.

I tried to move getIntent() into this function, but this is not allowed.

Any help would be much appreciated

Answer 1

Is this activity called by another activity? The intent will not be null only if previous activity supplies an intent to the current activity:

// previous activity
Intent intent = new Intent(FirstActivity.class, SecondActivity.class);
int value = 10;
intent.putIntExtra("key", value);
startActivity(intent);

// use this if want to return data 
//startActivityForResult(intent);

If this activity is the starting (main) activity or it is not called by any previous activity, then getIntent() is null, you need to initialize your own new Intent object.

// current activity in onCreate() method
if(getIntent() == null) {
    Intent intent = new Intent();
    int check = elsewhere.chk_intent(intent);
}