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Android Build a Weather App (2015) Hooking Up the Model to the View Plugging in the Data

Posted by Antwain Smith
Antwain Smith
414 Points

Plugging in the Data Video

To plug in my data I had to use the newest version of Butterknife. Instead of using the @InjectView annotation, I am using the @BindView annotation, which does the same thing. I'm receiving a null pointer exception whenever I try to include the method updateDisplay. java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference Should I be converting this information to a String? If so, how? I have tried Double.toString() method, for whatever reason that didn't work and tried to force me to declare the variable as a string and then try that method, which still did not work. I'm at a total loss as to what to do next. Please help!

1 Answer

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

Let's break down what "Attempt to invoke virtual method ... on a null object reference" You are trying to call a method (call and invoke are synonyms here). That method is setText(), which you are calling on the object to the left, a TextView. So the error message is saying that the TextView is null, not that there's any problem the data you're passing setText().

The most likely cause is a mismatch/typo in the id's you're binding between the Activity and XML for the layout, but htere can be other causes as well.