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POjava null pointer exception setting my action bar and fragment in my page viewer via button click
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copied!<p>I have a page viewer as my main display page and i have used codes from the java class itself to create my tabs and action bar like this:</p> <pre><code>protected ViewPager viewPager; private pageAdapter mAdapter; private ActionBar actionBar; // Tab titles private String[] tabs = { "Home", "BroadCast", "Friends" }; viewPager = (ViewPager) findViewById(R.id.pager); mAdapter = new pageAdapter(getSupportFragmentManager()); viewPager.setAdapter(mAdapter); actionBar = getActionBar(); actionBar.setHomeButtonEnabled(false); actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); for (String tab_name : tabs) { actionBar.addTab(actionBar.newTab().setText(tab_name).setTabListener(this)); } </code></pre> <p>i have three fragments for each tab that is loaded to the page viewer but on a particular fragment i want to set orload a another fragment into the page viewer when a button is clicked like so:</p> <pre><code>main mainly = new main(); public void onClick(View v) { // TODO Auto-generated method stub switch(v.getId()) { case R.id.blastbut: mactv = (MultiAutoCompleteTextView) this.getActivity().findViewById(R.id.blastarea); new postotimeline().execute(); ViewPager viewPager = (ViewPager) this.getView().findViewById(R.id.pager); pageAdapter mAdapter = new pageAdapter(mainly.getSupportFragmentManager()); viewPager.setAdapter(mAdapter); viewPager.setCurrentItem(0); Log.i("Blast", "Blasting"); //send getText to database and update list view break; case R.id.sf: break; case R.id.blastarea: break; } } </code></pre> <p>but it keeps giving me a null pointer exception on the <code>viewPager.setAdapter(mAdapter);</code> i have tried various ways but it keeps giving me the java null pointer exception. Please I am not so much of a professional in android. so kindly excuse me if i missed the obvious. </p> <p>Log cat:</p> <pre><code>12-20 05:15:35.785: E/AndroidRuntime(1119): FATAL EXCEPTION: main 12-20 05:15:35.785: E/AndroidRuntime(1119): Process: example.gbaalert, PID: 1119 12-20 05:15:35.785: E/AndroidRuntime(1119): java.lang.NullPointerException 12-20 05:15:35.785: E/AndroidRuntime(1119): at example.gbaalert.broadcastfragment.onClick(broadcastfragment.java:75) 12-20 05:15:35.785: E/AndroidRuntime(1119): at android.view.View.performClick(View.java:4424) 12-20 05:15:35.785: E/AndroidRuntime(1119): at android.view.View$PerformClick.run(View.java:18383) 12-20 05:15:35.785: E/AndroidRuntime(1119): at android.os.Handler.handleCallback(Handler.java:733) 12-20 05:15:35.785: E/AndroidRuntime(1119): at android.os.Handler.dispatchMessage(Handler.java:95) 12-20 05:15:35.785: E/AndroidRuntime(1119): at android.os.Looper.loop(Looper.java:137) 12-20 05:15:35.785: E/AndroidRuntime(1119): at android.app.ActivityThread.main(ActivityThread.java:4998) 12-20 05:15:35.785: E/AndroidRuntime(1119): at java.lang.reflect.Method.invokeNative(Native Method) 12-20 05:15:35.785: E/AndroidRuntime(1119): at java.lang.reflect.Method.invoke(Method.java:515) 12-20 05:15:35.785: E/AndroidRuntime(1119): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777) 12-20 05:15:35.785: E/AndroidRuntime(1119): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593) 12-20 05:15:35.785: E/AndroidRuntime(1119): at dalvik.system.NativeStart.main(Native Method) </code></pre> <p>NOTE: main is a Fragment Activity that implements tab listener that is bind to a page viewer(XML) and the class in which the button is clicked extends a Fragment</p>

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