I'm trying to add an button icon in the upper right hand side of action bar and I follow this tutorial
Claims1.java
public class Claims1 extends Fragment {
long fk;
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = this.getArguments();
fk = bundle.getLong("ab");
View claims = inflater.inflate(R.layout.claims, container, false);
ActionBar actionBar = getActivity().getActionBar();
actionBar.setDisplayOptions(actionBar.getDisplayOptions()
| ActionBar.DISPLAY_SHOW_CUSTOM);
ImageView imageView = new ImageView(actionBar.getThemedContext());
imageView.setScaleType(ImageView.ScaleType.CENTER);
imageView.setImageResource(R.mipmap.create);
ActionBar.LayoutParams layoutParams = new ActionBar.LayoutParams(
ActionBar.LayoutParams.WRAP_CONTENT,
ActionBar.LayoutParams.WRAP_CONTENT, Gravity.RIGHT
| Gravity.CENTER_VERTICAL);
layoutParams.rightMargin = 40;
imageView.setLayoutParams(layoutParams);
actionBar.setCustomView(imageView);
return claims;
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
private String[] mNavigationDrawerItemTitles;
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
ActionBarDrawerToggle mDrawerToggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTitle = mDrawerTitle = getTitle();
// get list items from strings.xml
mNavigationDrawerItemTitles = getResources().getStringArray(R.array.nav_drawer_items);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerToggle = new ActionBarDrawerToggle(
this,
mDrawerLayout,
R.mipmap.ic_drawer,
R.string.drawer_open,
R.string.drawer_close
)
{
/** Called when a drawer has settled in a completely closed state. */
public void onDrawerClosed(View view) {
super.onDrawerClosed(view);
getSupportActionBar().setTitle(mTitle);
}
/** Called when a drawer has settled in a completely open state. */
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
getSupportActionBar().setTitle(mDrawerTitle);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
// 2.1 create ActionBarDrawerToggle
ObjectDrawerItem[] drawerItem = new ObjectDrawerItem[5];
drawerItem[0] = new ObjectDrawerItem(R.mipmap.timesheet, "Time Sheet");
drawerItem[1] = new ObjectDrawerItem(R.mipmap.claims, "Claims");
drawerItem[2] = new ObjectDrawerItem(R.mipmap.project_icon, "Project");
drawerItem[3] = new ObjectDrawerItem(R.mipmap.report, "Report");
drawerItem[4] = new ObjectDrawerItem(R.mipmap.view, "View");
DrawerItemCustomAdapter adapter = new DrawerItemCustomAdapter(this, R.layout.listview_item_row, drawerItem);
mDrawerList.setAdapter(adapter);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void setTitle(CharSequence title) {
mTitle = title;
getSupportActionBar().setTitle(mTitle);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
mDrawerToggle.syncState();
}
public class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
private void selectItem(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment=new Information();
break;
case 1:
fragment=new Claims1();
Bundle bundle=new Bundle();
bundle.putLong("ab",WorkDetailsTable.ab);
fragment.setArguments(bundle);
break;
case 2:
fragment=new Project();
break;
case 3:
fragment=new Report();
break;
case 4:
fragment=new ViewView();
break;
default:
break;
}
if (fragment != null) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
setTitle(mNavigationDrawerItemTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
} else {
Log.e("MainActivity", "Error in creating fragment");
}
}
}
However, my app crashed. Do I need to add anything in my claims1.xml?
11-15 13:22:27.384 4199-4199/com.example.project.project E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.project.project, PID: 4199
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.app.ActionBar.getDisplayOptions()' on a null object reference
at com.example.project.project.Claims1.onCreateView(Claims1.java:26)
at android.app.Fragment.performCreateView(Fragment.java:2220)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:973)
(Claims1.java:26)
actionBar.setDisplayOptions(actionBar.getDisplayOptions()
| ActionBar.DISPLAY_SHOW_CUSTOM);
