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Android Android Fragments Tablet Time Adapt Together

Guy Bridge
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Guy Bridge
Android Development Techdegree Graduate 24,991 Points
Posted by Guy Bridge
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Guy Bridge
Android Development Techdegree Graduate 24,991 Points

Getting NPE now that I have created the RecyclerAdapter class

Hi,

I have just completed the steps in this video where we create the RecyclerAdapter class. The exception is:

FATAL EXCEPTION: main Process: au.com.wsit.smellslikebakin, PID: 6420 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageResource(int)' on a null object reference at au.com.wsit.smellslikebakin.RecyclerAdapter$ListViewHolder.bindView(RecyclerAdapter.java:59) at au.com.wsit.smellslikebakin.RecyclerAdapter.onBindViewHolder(RecyclerAdapter.java:31) at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5453)

Guy Bridge
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Guy Bridge
Android Development Techdegree Graduate 24,991 Points
Guy Bridge
.a{fill-rule:evenodd;}techdegree seal-36
Guy Bridge
Android Development Techdegree Graduate 24,991 Points

Line 59 looks like:

public void bindView(int position) { mIndex = position; mTextView.setText(Recipes.names[position]); mImageView.setImageResource(Recipes.resourceIds[position]); }

Seth Kroger
Seth Kroger
56,414 Points
Seth Kroger
Seth Kroger
56,414 Points

Code?

It looks like mImageView wasn't set correctly, though mTextView apparently was. You would have gotten a null pointer error on that line first if it wasn't.

Oziel Perez
Oziel Perez
61,321 Points
Oziel Perez
Oziel Perez
61,321 Points

In my case, I couldn't even get an error! App just closed at start up and there was no stacktrace in the logcat. If you are experiencing this, check if the answer below will help you.

3 Answers

Seth Kroger
Seth Kroger
56,414 Points
Seth Kroger
Seth Kroger
56,414 Points

In the two layout files that you choose from, grid_item.xml and list_item.xml, the ImageViews have different id names. Only one id is used in RecyclerAdapter. You need to have the same id name in both layouts for it to work.

Guy Bridge
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Guy Bridge
Android Development Techdegree Graduate 24,991 Points
Guy Bridge
.a{fill-rule:evenodd;}techdegree seal-36
Guy Bridge
Android Development Techdegree Graduate 24,991 Points

Thanks Seth, Yes that's working now.

I also had to surround the isTablet = getResources().getBoolean(R.bool.is_tablet); in a try catch block.

It seems that when the device is not a tablet this causes an exception;

 try
        {
            isTablet = getResources().getBoolean(R.bool.is_tablet);
        }
        catch(Exception e)
        {
            isTablet = false;
        }
Cindy Lea
PLUS
Cindy Lea
Courses Plus Student 6,497 Points
Cindy Lea
Cindy Lea
Courses Plus Student 6,497 Points

Please link your code. I wish everyone wouldnt just post errors & expect us to figure it out. Its much efficient if we see the code.