Android studio Fragment TabHost -
i want display fragmenttabhost in activity_main when button clicked.when click it, shows "unfortunately fragtabhost has stopped".below code. please me!!
mainactivity
public class mainactivity extends activity { @override protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.activity_main); button button=(button) findviewbyid(r.id.button); button.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { testfragment fragment=new testfragment(); fragmentmanager fragmentmanager=fragment.getfragmentmanager(); fragmenttransaction transaction=fragmentmanager.begintransaction(); transaction.replace(r.id.relative,fragment); transaction.commit(); } }); } @override public boolean oncreateoptionsmenu(menu menu) { // inflate menu; adds items action bar if present. getmenuinflater().inflate(r.menu.menu_main, menu); return true; } @override public boolean onoptionsitemselected(menuitem item) { // handle action bar item clicks here. action bar // automatically handle clicks on home/up button, long // specify parent activity in androidmanifest.xml. int id = item.getitemid(); //noinspection simplifiableifstatement if (id == r.id.action_settings) { return true; } return super.onoptionsitemselected(item); } } activity_main
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingleft="@dimen/activity_horizontal_margin" android:paddingright="@dimen/activity_horizontal_margin" android:paddingtop="@dimen/activity_vertical_margin" android:paddingbottom="@dimen/activity_vertical_margin" android:id="@+id/relative" tools:context=".mainactivity"> <button android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/button" android:text="tabhost"/> </relativelayout> test_fragment
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <framelayout android:id="@android:id/tabcontent" android:layout_width="0dp" android:layout_height="0dp" android:layout_weight="0" /> <framelayout android:id="@+id/realtabcontent" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"/> <tabwidget android:id="@android:id/tabs" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="0" android:orientation="horizontal" /> </linearlayout> testfragment
package com.example.sabudaniel61.fragtabhost; /** * created sabudaniel61 on 2015-09-30. */ import android.os.bundle; import android.support.v4.app.fragment; import android.support.v4.app.fragmenttabhost; import android.view.layoutinflater; import android.view.view; import android.view.viewgroup; import android.widget.textview; public class testfragment extends fragment { @override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) { fragmenttabhost tabhost = new fragmenttabhost(getactivity()); inflater.inflate(r.layout.test_fragment, tabhost); tabhost.setup(getactivity(), getchildfragmentmanager(), r.id.realtabcontent); tabhost.addtab(tabhost.newtabspec("simple") .setindicator("simple"), dummysectionfragment.class, null); tabhost.addtab(tabhost.newtabspec("contacts") .setindicator("contacts"), dummysectionfragment.class, null); return tabhost; } /** * dummy fragment representing section of app, * displays dummy text. */ public static class dummysectionfragment extends fragment { private static int count = 0; @override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) { view rootview = inflater.inflate(r.layout.fragment_section_dummy, container, false); ((textview) rootview.findviewbyid(android.r.id.text1)) .settext("dummy section " + count++); return rootview; } } } fragment_section_dummy
<textview xmlns:android="http://schemas.android.com/apk/res/android" android:id="@android:id/text1" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" android:textsize="24sp" android:padding="32dp" /> logcat:
09-30 00:43:18.676 28335-28335/com.example.sabudaniel61.fragtabhost e/androidruntime﹕ fatal exception: main process: com.example.sabudaniel61.fragtabhost, pid: 28335 java.lang.nullpointerexception: attempt invoke virtual method 'android.support.v4.app.fragmenttransaction android.support.v4.app.fragmentmanager.begintransaction()' on null object reference @ com.example.sabudaniel61.fragtabhost.mainactivity$1.onclick(mainactivity.java:24) @ android.view.view.performclick(view.java:4756) @ android.view.view$performclick.run(view.java:19749) @ android.os.handler.handlecallback(handler.java:739) @ android.os.handler.dispatchmessage(handler.java:95) @ android.os.looper.loop(looper.java:135) @ android.app.activitythread.main(activitythread.java:5221) @ java.lang.reflect.method.invoke(native method) @ java.lang.reflect.method.invoke(method.java:372) @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:899) @ com.android.internal.os.zygoteinit.main(zygoteinit.java:694) 09-30 00:48:19.063 28335-28335/com.example.sabudaniel61.fragtabhost i/process﹕ sending signal. pid: 28335 sig: 9
you getting nullpointerexception @ line# 24 in mainactivity.
replace
fragmentmanager fragmentmanager=fragment.getfragmentmanager(); with
fragmentmanager fragmentmanager=this.getsupportfragmentmanager(); in mainactivity.
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