I am using multiple fragments in my main activity now I tried to access childs of each fragment but it giving me null exception when its childs are access.
On clicking button1 not changing data and on clicking button2 app crashing. Here is my code:
MainActivity
public class MainActivity extends Activity {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Fragment fr;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentManager = getFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
}
public void selectFrag(View view) {
Fragment fr;
if(view == findViewById(R.id.button1)) {
//add a fragment
fr = new FragmentOne();
TextView textView1 = (TextView) fr.getView().findViewById(R.id.textView1);
textView1.setText("Fragment One");
}else {
//add a fragment
fr = new FragmentTwo();
TextView textView2 = (TextView) fr.getView().findViewById(R.id.textView2);
textView2.setText("Fragment Two");
}
fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_place, fr);
fragmentTransaction.commit();
}
}
FragmentOne
public class FragmentOne extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
//Inflate the layout for this fragment
return inflater.inflate(
R.layout.fragment_one, container, false);
}
}
FragmentTwo
public class FragmentTwo extends Fragment{
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
/**
* Inflate the layout for this fragment
*/
return inflater.inflate(
R.layout.fragment_two, container, false);
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="@+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Fragment No.1"
android:onClick="selectFrag" />
<Button
android:id="@+id/button2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="selectFrag"
android:text="Fragment No.2" />
<fragment
android:name="com.javacodegeeks.android.fragmentstest.FragmentOne"
android:id="@+id/fragment_place"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
fragment_one.xml
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#00ffff">
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="This is fragment No.1"
android:textStyle="bold" />
</LinearLayout>
fragment_two.xml
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#ffff00">
<TextView
android:id="@+id/textView2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="This is fragment No.2"
android:textStyle="bold" />
</LinearLayout>
CrashReport on clicking button2:
07-07 14:41:40.505: E/AndroidRuntime(15175): FATAL EXCEPTION: main
07-07 14:41:40.505: E/AndroidRuntime(15175): Process: com.javacodegeeks.android.fragmentstest, PID: 15175
07-07 14:41:40.505: E/AndroidRuntime(15175): java.lang.IllegalStateException: Could not execute method of the activity
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.view.View$1.onClick(View.java:3851)
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.view.View.performClick(View.java:4466)
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.view.View$PerformClick.run(View.java:18833)
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.os.Handler.handleCallback(Handler.java:808)
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.os.Handler.dispatchMessage(Handler.java:103)
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.os.Looper.loop(Looper.java:193)
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.app.ActivityThread.main(ActivityThread.java:5299)
07-07 14:41:40.505: E/AndroidRuntime(15175): at java.lang.reflect.Method.invokeNative(Native Method)
07-07 14:41:40.505: E/AndroidRuntime(15175): at java.lang.reflect.Method.invoke(Method.java:515)
07-07 14:41:40.505: E/AndroidRuntime(15175): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
07-07 14:41:40.505: E/AndroidRuntime(15175): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:652)
07-07 14:41:40.505: E/AndroidRuntime(15175): at dalvik.system.NativeStart.main(Native Method)
07-07 14:41:40.505: E/AndroidRuntime(15175): Caused by: java.lang.reflect.InvocationTargetException
07-07 14:41:40.505: E/AndroidRuntime(15175): at java.lang.reflect.Method.invokeNative(Native Method)
07-07 14:41:40.505: E/AndroidRuntime(15175): at java.lang.reflect.Method.invoke(Method.java:515)
07-07 14:41:40.505: E/AndroidRuntime(15175): at android.view.View$1.onClick(View.java:3846)
07-07 14:41:40.505: E/AndroidRuntime(15175): ... 11 more
07-07 14:41:40.505: E/AndroidRuntime(15175): Caused by: java.lang.NullPointerException
07-07 14:41:40.505: E/AndroidRuntime(15175): at com.javacodegeeks.android.fragmentstest.MainActivity.selectFrag(MainActivity.java:37)
07-07 14:41:40.505: E/AndroidRuntime(15175): ... 14 more
