Android ClassNotFoundException with ViewPager
android, android-viewpager, classnotfoundexception, inflate, java
Solution
What does your XML look like in the layout file? If you simply put
<ViewPager
android:layout_width="..."
android:layout_height="..." />
Your application will crash because `ViewPager` is not located in the core SDK package with other widgets, it's in the support library. You need to put the fully qualified name
<android.support.v4.view.ViewPager
android:layout_width="..."
android:layout_height="..." />
Also, as others have mentioned, make sure the support library JAR is properly included in your project.
HTH
Problem
I am getting the following error, which I don't understand... ``` 06-15 22:06:49.196: W/dalvikvm(17622): threadid=1: thread exiting with uncaught exception (group=0x40bcc1f8) 06-15 22:07:05.031: W/dalvikvm(17877): threadid=1: thread exiting with uncaught exception (group=0x40bcc1f8) 06-15 22:07:05.031: E/AndroidRuntime(17877): FATAL EXCEPTION: main 06-15 22:07:05.031: E/AndroidRuntime(17877): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.whipple.android/com.whipple.android.StockActivity}: android.view.InflateException: Binary XML file line #6: Error inflating class ViewPager 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1968) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1993) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.ActivityThread.access$600(ActivityThread.java:127) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1159) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.os.Handler.dispatchMessage(Handler.java:99) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.os.Looper.loop(Looper.java:137) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.ActivityThread.main(ActivityThread.java:4512) 06-15 22:07:05.031: E/AndroidRuntime(17877): at java.lang.reflect.Method.invokeNative(Native Method) 06-15 22:07:05.031: E/AndroidRuntime(17877): at java.lang.reflect.Method.invoke(Method.java:511) 06-15 22:07:05.031: E/AndroidRuntime(17877): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794) 06-15 22:07:05.031: E/AndroidRuntime(17877): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:561) 06-15 22:07:05.031: E/AndroidRuntime(17877): at dalvik.system.NativeStart.main(Native Method) 06-15 22:07:05.031: E/AndroidRuntime(17877): Caused by: android.view.InflateException: Binary XML file line #6: Error inflating class ViewPager 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:691) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.rInflate(LayoutInflater.java:739) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.inflate(LayoutInflater.java:489) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.inflate(LayoutInflater.java:396) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.inflate(LayoutInflater.java:352) 06-15 22:07:05.031: E/AndroidRuntime(17877): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:272) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.Activity.setContentView(Activity.java:1851) 06-15 22:07:05.031: E/AndroidRuntime(17877): at com.whipple.android.StockActivity.onCreate(StockActivity.java:17) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.Activity.performCreate(Activity.java:4481) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1932) 06-15 22:07:05.031: E/AndroidRuntime(17877): ... 11 more 06-15 22:07:05.031: E/AndroidRuntime(17877): Caused by: java.lang.ClassNotFoundException: android.view.ViewPager 06-15 22:07:05.031: E/AndroidRuntime(17877): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61) 06-15 22:07:05.031: E/AndroidRuntime(17877): at java.lang.ClassLoader.loadClass(ClassLoader.java:501) 06-15 22:07:05.031: E/AndroidRuntime(17877): at java.lang.ClassLoader.loadClass(ClassLoader.java:461) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.createView(LayoutInflater.java:552) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:636) 06-15 22:07:05.031: E/AndroidRuntime(17877): at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:653) 06-15 22:07:05.031: E/AndroidRuntime(17877): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:678) 06-15 22:07:05.031: E/AndroidRuntime(17877): ... 21 more ``` This is my code... ``` public class StockActivity extends Activity { public ListAdapter listadapter; private StockPageAdapter myAdapter; private ViewPager myPager; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); super.setContentView(R.layout.main); this.myAdapter = new StockPageAdapter(this); this.myPager = (ViewPager)super.findViewById(R.id.pager); this.myPager.setAdapter(myAdapter); } ``` It's a `ListAdapter` with a `ViewPager` to scroll through the lists. I'm extending `BaseAdapter` and inflating the view with this code... ``` LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); row = inflater.inflate(R.layout.row, null); ``` Could someone please help me to understand what is wrong.