Question

I am developing an Android application for >= API 8.

For compatibility reasons, the application uses Actionbar Sherlock. Before API 11, the NumberPicker was an internal widget, but I need the NumberPicker, so I had to come up with another solution.

After some Googling, I stumbled upon this NumberPicker from Mike Novak. I implemented it but unfortunately, when I click on the preference that should bring up the dialog with the numberpicker, the application crashes.

It seems there is something wrong with the reference to the layout (logcat says com.example.widget.NumberPicker is used) file, but the source references to com.michaelnovakjr.numberpicker.R.layout.pref_number_picker as you can see here.

LogCat output:

12-13 13:59:27.516: W/dalvikvm(11642): threadid=1: thread exiting with uncaught exception (group=0x40dbe930)
12-13 13:59:27.555: E/AndroidRuntime(11642): FATAL EXCEPTION: main
12-13 13:59:27.555: E/AndroidRuntime(11642): android.view.InflateException: Binary XML file line #24: Error inflating class com.michaelnovakjr.numberpicker.NumberPicker
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.createView(LayoutInflater.java:613)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:687)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.preference.DialogPreference.onCreateDialogView(DialogPreference.java:343)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.preference.DialogPreference.showDialog(DialogPreference.java:287)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.preference.DialogPreference.onClick(DialogPreference.java:266)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.preference.Preference.performClick(Preference.java:949)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.preference.PreferenceScreen.onItemClick(PreferenceScreen.java:215)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.widget.AdapterView.performItemClick(AdapterView.java:298)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.widget.AbsListView.performItemClick(AbsListView.java:1100)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.widget.AbsListView$PerformClick.run(AbsListView.java:2749)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.widget.AbsListView$1.run(AbsListView.java:3423)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.os.Handler.handleCallback(Handler.java:725)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.os.Handler.dispatchMessage(Handler.java:92)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.os.Looper.loop(Looper.java:137)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.app.ActivityThread.main(ActivityThread.java:5039)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at java.lang.reflect.Method.invokeNative(Native Method)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at java.lang.reflect.Method.invoke(Method.java:511)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at dalvik.system.NativeStart.main(Native Method)
12-13 13:59:27.555: E/AndroidRuntime(11642): Caused by: java.lang.reflect.InvocationTargetException
12-13 13:59:27.555: E/AndroidRuntime(11642):    at java.lang.reflect.Constructor.constructNative(Native Method)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.createView(LayoutInflater.java:587)
12-13 13:59:27.555: E/AndroidRuntime(11642):    ... 23 more
12-13 13:59:27.555: E/AndroidRuntime(11642): Caused by: android.view.InflateException: Binary XML file line #22: Error inflating class com.example.widget.NumberPickerButton
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:698)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.inflate(LayoutInflater.java:459)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at com.michaelnovakjr.numberpicker.NumberPicker.<init>(NumberPicker.java:125)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at com.michaelnovakjr.numberpicker.NumberPicker.<init>(NumberPicker.java:117)
12-13 13:59:27.555: E/AndroidRuntime(11642):    ... 26 more
12-13 13:59:27.555: E/AndroidRuntime(11642): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.widget.NumberPickerButton" on path: /data/app/nl.livecarb.android-1.apk
12-13 13:59:27.555: E/AndroidRuntime(11642):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.createView(LayoutInflater.java:552)
12-13 13:59:27.555: E/AndroidRuntime(11642):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:687)
12-13 13:59:27.555: E/AndroidRuntime(11642):    ... 31 more

res/xml/main_preferences.xml

    <?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:picker="http://schemas.android.com/apk/res/nl.livecarb.android" >

    <PreferenceCategory android:title="@string/pref_cat_title_medical" >
        <com.michaelnovakjr.numberpicker.NumberPickerPreference
            android:key="@string/pref_key_ratio"
            android:summary="Bla"
            android:title="@string/pref_title_ratio"
            picker:defaultValue="1"
            picker:endRange="31"
            picker:startRange="1" />
    </PreferenceCategory>
    <PreferenceCategory android:title="@string/pref_cat_title_other" >
        <Preference
            android:key="@string/pref_key_disclaimer"
            android:title="@string/pref_title_disclaimer" />
    </PreferenceCategory>

</PreferenceScreen>

SettingsActivity.java

public class SettingsActivity extends PreferenceActivity implements OnPreferenceClickListener {

    @SuppressWarnings("deprecation")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if(android.os.Build.VERSION.SDK_INT >= 11) {
            getFragmentManager().beginTransaction().replace(android.R.id.content, new SettingsFragment(), "settings").commit();
        } else {
            addPreferencesFromResource(R.xml.main); 
        }
    }

    class SettingsFragment extends PreferenceFragment {

        private Preference preferences = null;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            addPreferencesFromResource(R.xml.main);

            preferences = findPreference(getResources().getString(R.string.pref_key_disclaimer));
            preferences.setOnPreferenceClickListener(SettingsActivity.this);
        }
    }
}

The error
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.widget.NumberPickerButton" on path: /data/app/nl.livecarb.android-1.apk doesn’t make any sense to me, since I never used com.example.widget.NumberPickerButton. Neither the NumberPicker lib does.

Things I did trying to solve this problem:

1. How to use NumberPicker from QuietlyCoding in preferences?
2. Double checked the library project is referenced correct
3. Cleaned the project (including all libs)

Any thoughts?

Answer 1

Are you working off the master branch of the project? Try searching your code for a reference to that example package. I just took a look in the library and I don’t see any reference to it.