FindViewById In A Subclassed SurfaceView Throwing RuntimeException

This code works fine if I move the findViewById call in to the Activity. Any hints as to why it doesn't work from inside the LearningView class? I've tried moving the TextView insi

Solution 1:

You are crashing because your TextView is null after findViewById(). The TextView is not a child of the SurfaceView, therefore calling findViewById() with the SurfaceView as the starting point will not find it.

Solution 2:

You can cast the context as an Activity and find the view as follows:

(TextView) ((Activity) context).findViewById(R.id.contents);

Now it won't be null.

Solution 3:

I was having the same problem and the answer provided by Loke resolved my issue. I don't know if casting is a good clean way to program for android sdk. here is what my code ended up like:

my activity had:

setContentView(R.layout.game);

my game.xml:

<TextView  
    android:text="@string/text_foul_counter_1"  
    android:layout_height="wrap_content"  
    android:background="#fff"  
    android:gravity="center"  
    android:textColor="#000"  
    android:id="@+id/TextViewFoulCounter1"  
    android:layout_width="wrap_content"  
    android:layout_below="@+id/TextViewFoul1" 
    android:padding="2dp"></TextView>

and calling finViewById from within my class: public class PlayerView extends Activity implements OnClickListener, OnLongClickListener {...}

without casting I used to get a null pointer exception. below is the code line that works now.

foulsTextViewTeam1 = (TextView) ((Activity) context).findViewById(R.id.TextViewFoulCounter1);