CODEWITHSUNDEEP
androidandroid-layout
James
James

Reputation: 191

Use a subclass to modify view of main activity

I have a main activity with TextViews and class that want's modify the main activity's TextViews.

I keep generating NullPointerException errors in my findViewbyID method in my class. I'm assuming because I'm not passing the View to the class method. How do I got about doing this?

Upvotes: 0

Views: 639

Answers (2)

Aditya Kushwaha
Aditya Kushwaha

Reputation: 837

In your Activity , if you use setcontentView(R.layout.yourlayout) then all the subsequent findViewById() correspond to the views in yourlayout.xml. In the second activity your are trying to find views of the layout of the first activity, that is why you are getting the NullPointerException. Why do you want to manipulate views of this activity in another activity ? I suggest you manipulate the views in the first activity.

Upvotes: 0

ρяσѕρєя K
ρяσѕρєя K

Reputation: 132992

you will need to to pass Activity instance to your non Activity class using constructor to access all UI elements from non Activity Class as :

public class NonActivity{
Activity activity;
Context context;

public NonActivity(Activity activity,Context context) {
  this.activity=activity;
  this.context=context;
 }

}

now you can access UI elements from Activity in NonActivity class as:

 TextView textview=(TextView)activity.findViewbyID(R.id.textview);

Upvotes: 4

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