CODEWITHSUNDEEP
javaandroid
Rhys Drury
Rhys Drury

Reputation: 315

Scrolling crashes program when scrolling through grid view

When I try to scroll through my word search, my program crashes throwing a null pointer exception. However I have no idea why,

my grid view is created with an array

    String [] WordSearch =  new String[FormattedWords.length];

    for(int i = 1; i<FormattedWords.length ;i++)
    {
        WordSearch[i-1] = FormattedWords[i];
    }

, the logcat is giving me this also

04-17 14:19:37.623: E/AndroidRuntime(5969): FATAL EXCEPTION: main
04-17 14:19:37.623: E/AndroidRuntime(5969): java.lang.NullPointerException
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:394)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.AbsListView.obtainView(AbsListView.java:2267)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.GridView.makeAndAddView(GridView.java:1331)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.GridView.makeRow(GridView.java:331)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.GridView.fillDown(GridView.java:283)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.GridView.fillGap(GridView.java:243)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.AbsListView.trackMotionScroll(AbsListView.java:5036)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.AbsListView.scrollIfNeeded(AbsListView.java:3193)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.AbsListView.startScrollIfNeeded(AbsListView.java:3138)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.widget.AbsListView.onTouchEvent(AbsListView.java:3463)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.View.dispatchTouchEvent(View.java:7127)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2170)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1905)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1925)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1379)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.app.Activity.dispatchTouchEvent(Activity.java:2396)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1873)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.View.dispatchPointerEvent(View.java:7307)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3172)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3117)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4153)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4132)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4224)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:163)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:4203)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:4243)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.Choreographer.doCallbacks(Choreographer.java:555)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.Choreographer.doFrame(Choreographer.java:523)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.os.Handler.handleCallback(Handler.java:615)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.os.Handler.dispatchMessage(Handler.java:92)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.os.Looper.loop(Looper.java:137)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at android.app.ActivityThread.main(ActivityThread.java:4745)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at java.lang.reflect.Method.invokeNative(Native Method)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at java.lang.reflect.Method.invoke(Method.java:511)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
04-17 14:19:37.623: E/AndroidRuntime(5969):     at dalvik.system.NativeStart.main(Native Method)

Any ideas?

Upvotes: 0

Views: 616

Answers (2)

Pandiyan T
Pandiyan T

Reputation: 59

if value of FormattedWords[i] is equals to null means app will crashed when view comes front

Upvotes: 0

drunkenRabbit
drunkenRabbit

Reputation: 394

Why does the for loop start at 1 and insert the data as it does? The NullPointerException is most likely caused by the for loop to insert Strings into the WordSearch Array.

eg.

Assuming FormattedWords is an Array (you are using the .length attribute), if FormattedWords.length is 3 and contains:

FormattedWords[0] = "a";
FormattedWords[1] = "b";
FormattedWords[2] = "c";

After the for loop WordSearch will contain:

WordSearch[0] = "b";
WordSearch[1] = "c";
WordSearch[2] = null;

Which is here your problem seems to be.

EDIT

If first value in FormattedWords is to be omitted then you should initiate WordSearch to size FormattedWords.lenght - 1 to avoid the NPE.

eg.

String [] WordSearch =  new String[FormattedWords.length - 1];

Upvotes: 3

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