The problem I face is how to navigate through tab activity with nested activities based on Button click android.
I have 3 tabs Dashboard, Vehicle search, and Location search. When I press the location search tab I get a Edit text(to enter the zip code) and go button(when I press it I should get the locations in 100 miles of zip code in different page called Location Search Results page) My specific problem is the app crashes when I press go button and before I get the locations I have MainActivity class which extends the TabActivity and define all the tabs public class MainActivity extends TabActivity { public TabHost tabHost; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tabHost = (TabHost) findViewById(android.R.id.tabhost); TabHost.TabSpec spec; Intent intent; intent = new Intent().setClass(this, DashBoard.class); spec = tabHost.newTabSpec("dashboard").setIndicator("DashBoard").setContent(intent); tabHost.addTab(spec); intent = new Intent().setClass(this, VehicleSearch.class); spec = tabHost.newTabSpec("vehicleSearch").setIndicator("VehicleSearch").setContent(intent); tabHost.addTab(spec); intent = new Intent().setClass(this, BranchSearch.class); spec = tabHost.newTabSpec("branchSearch").setIndicator("BranchSearch").setContent(intent); tabHost.addTab(spec); tabHost.setCurrentTab(3); } I also have the BranchSearchHelper class which extends ActivityGroup public class BranchSearchHelper extends ActivityGroup { public static BranchSearchHelper branchSearch; private ArrayList<View> history; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); branchSearch = this; this.history = new ArrayList<View>(); View view = getLocalActivityManager().startActivity("BranchSearch", new Intent(this,BranchSearch.class) .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView(); replaceView(view); } public void replaceView(View v) { // Adds the old one to history history.add(v); // Changes this Groups View to the new View. setContentView(v); } public void back() { if(history.size() > 0) { history.remove(history.size()-1); setContentView(history.get(history.size()-1)); } else { finish(); } } @Override public void onBackPressed() { BranchSearchHelper.branchSearch.back(); return; } } The class BranchSearch extends Activity public class BranchSearch extends Activity implements OnClickListener { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.branchsearch); Button locSearch = (Button) findViewById(R.id.btnlocSearch); locSearch.setOnClickListener(this); } public void onClick(View v) { // TODO Auto-generated method stub EditText editText = (EditText) findViewById(R.id.lsearch); Bundle bundle = new Bundle(); bundle.putString("zipCode", editText.getText().toString() ); Intent i = new Intent(getApplicationContext(), LocationSearchResults.class); i.putExtras(bundle); i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); View view = BranchSearchHelper.branchSearch.getLocalActivityManager().startActivity("Locations Results",i).getDecorView(); BranchSearchHelper.branchSearch.replaceView(view); } } I always get an javaNUllPointerexception the exception throws at View view = BranchSearchHelper.branchSearch.getLocalActivityManager().startActivity("Locations Results",i).getDecorView(); because branchSearch is null so can you please tell me how I can keep the track of tabs and show the all the location results when I press the go button without crashing the application. ( what parts of code should I change) There is a class called LocationSearchResults which handles the displaying of all location search results. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en