不幸 <app> 已在android模拟器错误中停止。 如何解决呢？

Question

I am new to android. I'm getting a message in AVD like "Unfortunately app has stopped". I'm just trying make a simple example about fragment. Please help me to solve this.

My MainActivity.java

package com.example.fragments;

import android.os.Bundle;
import android.app.Activity;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

}

Fragement1.java

package com.example.fragments;


import android.annotation.SuppressLint;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

@SuppressLint("NewApi")

public class Fragment1 extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub

    //----Inflate the layout for this fragment----
    return inflater.inflate(R.layout.fragment1, container, false);
}

}

Fragment2.java

package com.example.fragments;

import android.annotation.SuppressLint;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

@SuppressLint("NewApi")
public class Fragment2 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub


        //----Inflate the layout for this fragment----
        return inflater.inflate(R.layout.fragment2, container, false);
    }

}

fragment1.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:orientation="vertical"
    android:background="#00FF00" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="This is fragment #1"
        android:textColor="#000000"
        android:textSize="25sp" />

</LinearLayout>

fragment2.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:orientation="vertical"
    android:background="#FFFE00" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="This is fragment #2"
        android:textColor="#000000"
        android:textSize="25sp" />


</LinearLayout>

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal" >

   <fragment
       android:name="com.example.Fragments.Fragment1"
       android:id="@+id/fragment1"
       android:layout_weight="1"
       android:layout_width="0px"
       android:layout_height="match_parent" />

   <fragment
       android:name="com.example.Fragments.Fragment2"
       android:id="@+id/fragment2"
       android:layout_weight="1"
       android:layout_width="0px"
       android:layout_height="match_parent" />

</LinearLayout>

My Logcat

03-05 08:05:40.300: D/AndroidRuntime(1219): Shutting down VM
03-05 08:05:40.300: W/dalvikvm(1219): threadid=1: thread exiting with uncaught exception (group=0xa5ad8ba8)
03-05 08:05:40.330: E/AndroidRuntime(1219): FATAL EXCEPTION: main
03-05 08:05:40.330: E/AndroidRuntime(1219): Process: com.example.fragments, PID: 1219
03-05 08:05:40.330: E/AndroidRuntime(1219): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.fragments/com.example.fragments.MainActivity}: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.os.Looper.loop(Looper.java:136)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.ActivityThread.main(ActivityThread.java:5017)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at java.lang.reflect.Method.invokeNative(Native Method)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at java.lang.reflect.Method.invoke(Method.java:515)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at dalvik.system.NativeStart.main(Native Method)
03-05 08:05:40.330: E/AndroidRuntime(1219): Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:713)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.Activity.setContentView(Activity.java:1929)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at com.example.fragments.MainActivity.onCreate(MainActivity.java:11)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.Activity.performCreate(Activity.java:5231)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
03-05 08:05:40.330: E/AndroidRuntime(1219):     ... 11 more
03-05 08:05:40.330: E/AndroidRuntime(1219): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.Fragments.Fragment1: make sure class name exists, is public, and has an empty constructor that is public
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.Fragment.instantiate(Fragment.java:597)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.Fragment.instantiate(Fragment.java:561)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.Activity.onCreateView(Activity.java:4778)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:689)
03-05 08:05:40.330: E/AndroidRuntime(1219):     ... 21 more
03-05 08:05:40.330: E/AndroidRuntime(1219): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.Fragments.Fragment1" on path: DexPathList[[zip file "/data/app/com.example.fragments-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.fragments-1, /system/lib]]
03-05 08:05:40.330: E/AndroidRuntime(1219):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
03-05 08:05:40.330: E/AndroidRuntime(1219):     at android.app.Fragment.instantiate(Fragment.java:583)
03-05 08:05:40.330: E/AndroidRuntime(1219):     ... 24 more
03-05 08:05:48.630: I/Process(1219): Sending signal. PID: 1219 SIG: 9

Please tell me why i'm getting like this. tell me the solution. thanks very much!!!

Answer 1

Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.Fragments.Fragment1: make sure class name exists, is public, and has an empty constructor that is public

Change

<fragment
   android:name="com.example.Fragments.Fragment1"

to

<fragment
   android:name="com.example.fragments.Fragment1" // notice fragments. f in small

coz package name is

package com.example.fragments;

Similarly

<fragment
   android:name="com.example.fragments.Fragment2