Android Fragment Platform

I have below errors when creating a simple example fragment.

09-05 07:57:28.570: E/AndroidRuntime(1138): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.fragment_one.f_one: make sure class name exists, is public, and has an empty constructor that is public 09-05 08:57:03.058: E/AndroidRuntime(1477): FATAL EXCEPTION: main 09-05 08:57:03.058: E/AndroidRuntime(1477): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.fragments_one/com.example.fragments_one.MainActivity}: android.view.InflateException: Binary XML file line #5: Error inflating class fragment 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.ActivityThread.access$600(ActivityThread.java:123) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.os.Handler.dispatchMessage(Handler.java:99) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.os.Looper.loop(Looper.java:137) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.ActivityThread.main(ActivityThread.java:4424) 09-05 08:57:03.058: E/AndroidRuntime(1477): at java.lang.reflect.Method.invokeNative(Native Method) 09-05 08:57:03.058: E/AndroidRuntime(1477): at java.lang.reflect.Method.invoke(Method.java:511) 09-05 08:57:03.058: E/AndroidRuntime(1477): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 09-05 08:57:03.058: E/AndroidRuntime(1477): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 09-05 08:57:03.058: E/AndroidRuntime(1477): at dalvik.system.NativeStart.main(Native Method) 09-05 08:57:03.058: E/AndroidRuntime(1477): Caused by: android.view.InflateException: Binary XML file line #5: Error inflating class fragment 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:697) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.view.LayoutInflater.rInflate(LayoutInflater.java:739) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.view.LayoutInflater.inflate(LayoutInflater.java:489) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.view.LayoutInflater.inflate(LayoutInflater.java:396) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.view.LayoutInflater.inflate(LayoutInflater.java:352) 09-05 08:57:03.058: E/AndroidRuntime(1477): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:251) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.Activity.setContentView(Activity.java:1835) 09-05 08:57:03.058: E/AndroidRuntime(1477): at com.example.fragments_one.MainActivity.onCreate(MainActivity.java:12) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.Activity.performCreate(Activity.java:4465) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920) 09-05 08:57:03.058: E/AndroidRuntime(1477): ... 11 more 09-05 08:57:03.058: E/AndroidRuntime(1477): Caused by: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.fragment_one.f_one: make sure class name exists, is public, and has an empty constructor that is public 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.support.v4.app.Fragment.instantiate(Fragment.java:395) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.support.v4.app.Fragment.instantiate(Fragment.java:363) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:264) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:669) 09-05 08:57:03.058: E/AndroidRuntime(1477): ... 21 more 09-05 08:57:03.058: E/AndroidRuntime(1477): Caused by: java.lang.ClassNotFoundException: com.example.fragment_one.f_one 09-05 08:57:03.058: E/AndroidRuntime(1477): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61) 09-05 08:57:03.058: E/AndroidRuntime(1477): at java.lang.ClassLoader.loadClass(ClassLoader.java:501) 09-05 08:57:03.058: E/AndroidRuntime(1477): at java.lang.ClassLoader.loadClass(ClassLoader.java:461) 09-05 08:57:03.058: E/AndroidRuntime(1477): at android.support.v4.app.Fragment.instantiate(Fragment.java:385) 09-05 08:57:03.058: E/AndroidRuntime(1477): ... 24 more 

Primary activity

 package com.example.fragments_one; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.view.Menu; public class MainActivity extends FragmentActivity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } } 

activity_main.xml

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" > <fragment android:id="@+id/f_one" android:name="com.example.fragment_one.f_one" android:layout_width="0px" android:layout_height="match_parent" android:layout_weight="1" /> <fragment android:id="@+id/f_two" android:name="com.example.fragment_one.f_two" android:layout_width="0px" android:layout_height="match_parent" android:layout_weight="1" /> </LinearLayout> 

Fragment Layouts

1.f_one.xml

 <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#00FF00" android:orientation="vertical" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="This is fragment #1" android:textColor="#000000" android:textSize="25sp" /> </LinearLayout> 

f_two.xml

 <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#FFFE00" android:orientation="vertical" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="This is fragment #2" android:textColor="#000000" android:textSize="25sp" /> </LinearLayout> 

my fragment class

 package com.example.fragments_one; import android.app.Fragment; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; public class f_one extends Fragment { @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // ---Inflate the layout for this fragment--- return inflater.inflate(R.layout.f_one, container, false); } } 

 package com.example.fragments_one; import android.app.Fragment; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; public class f_two extends Fragment { @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // ---Inflate the layout for this fragment--- return inflater.inflate(R.layout.f_two, container, false); } } 
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1 answer

In the fragment, you must specify the class :

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" > <fragment android:id="@+id/f_one" android:name="com.example.fragment_one.f_one" class="com.example.fragment_one.f_one" android:layout_width="0px" android:layout_height="match_parent" android:layout_weight="1" /> <fragment android:id="@+id/f_two" android:name="com.example.fragment_one.f_two" class="com.example.fragment_one.f_two" android:layout_width="0px" android:layout_height="match_parent" android:layout_weight="1" /> </LinearLayout> 
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Source: https://habr.com/ru/post/924612/


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