Tabhost inside another tab host

Question

i have a tabhost in my activity. there are 5 tabs and one of these tab contain another tabHost. i need to display my 2nd tabHost under the tabHost.

ie, my tabactivity has 5 tabs.and in my 3rd tab contains another TabHost.

give me any idea of that. this is how i initialize the tabhosts.

TabHost mytab;
mytab = (TabHost)findViewById(android.R.id.tabhost);

the error displayed in logcat

02-19 10:46:29.207: E/AndroidRuntime(814): FATAL EXCEPTION: main

02-19 10:46:29.207: E/AndroidRuntime(814): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.netmdapp1/com.example.netmdapp1.PatientSubTabActivity}: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.netmdapp1/com.example.netmdapp1.Appointment}: java.lang.NullPointerException 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.ActivityThread.startActivityNow(ActivityThread.java:1487) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339) 02-19 10:46:29.207: E/AndroidRuntime(814): at com.example.netmdapp1.PatientGroupActivity.startChildActivity(PatientGroupActivity.java:48) 02-19 10:46:29.207: E/AndroidRuntime(814): at com.example.netmdapp1.PatientsCustomView$3.onClick(PatientsCustomView.java:112) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.view.View.performClick(View.java:2485) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.view.View$PerformClick.run(View.java:9080) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.os.Handler.handleCallback(Handler.java:587) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.os.Handler.dispatchMessage(Handler.java:92) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.os.Looper.loop(Looper.java:123) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.ActivityThread.main(ActivityThread.java:3683) 02-19 10:46:29.207: E/AndroidRuntime(814): at java.lang.reflect.Method.invokeNative(Native Method) 02-19 10:46:29.207: E/AndroidRuntime(814): at java.lang.reflect.Method.invoke(Method.java:507) 02-19 10:46:29.207: E/AndroidRuntime(814): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 02-19 10:46:29.207: E/AndroidRuntime(814): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 02-19 10:46:29.207: E/AndroidRuntime(814): at dalvik.system.NativeStart.main(Native Method) 02-19 10:46:29.207: E/AndroidRuntime(814): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.netmdapp1/com.example.netmdapp1.Appointment}: java.lang.NullPointerException 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.ActivityThread.startActivityNow(ActivityThread.java:1487) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:654) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.widget.TabHost.setCurrentTab(TabHost.java:326) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.widget.TabHost.addTab(TabHost.java:216) 02-19 10:46:29.207: E/AndroidRuntime(814): at com.example.netmdapp1.PatientSubTabActivity.setupTab(PatientSubTabActivity.java:57) 02-19 10:46:29.207: E/AndroidRuntime(814): at com.example.netmdapp1.PatientSubTabActivity.onCreate(PatientSubTabActivity.java:30) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 02-19 10:46:29.207: E/AndroidRuntime(814): ... 16 more 02-19 10:46:29.207: E/AndroidRuntime(814): Caused by: java.lang.NullPointerException 02-19 10:46:29.207: E/AndroidRuntime(814): at com.example.netmdapp1.Appointment.onCreate(Appointment.java:88) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 02-19 10:46:29.207: E/AndroidRuntime(814): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 02-19 10:46:29.207: E/AndroidRuntime(814): ... 26 more

Answer 1

tabHost.setCurrentTab(0); property decides the default tab. So, if you write tabHost.setCurrentTab(n); then nth tab will be default tab.