Android 碎片未能膨胀

这件事我有点发抖，所以请容忍我。我试图自学，目前正在编写《WROX Android 4初学者应用程序开发》一书。我现在在“片段之间的通信”一节，我觉得我明白了，但是当我运行从书中直接获取的代码时，我在logcat中得到了“充气失败”。下面是XML，后面是.java文件，然后是错误。我不知道是什么杀死了这个：

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>

Fragment1.java：

package com.example.fragments;

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

public class Fragment1 extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // ---Inflate the layout for this fragment---
        return inflater.inflate(R.layout.fragment1, container, false);
    }

}

Fragment2.java：

package com.example.fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class Fragment2 extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, 
            ViewGroup container, Bundle savedInstanceState) {
        //---Inflate the layout for this fragment---
        return inflater.inflate(
                R.layout.fragment2, container, false);
    }

    @Override
    public void onStart() {
        super.onStart();
        //---Button View---
        Button btnGetText = (Button)
                getActivity().findViewById(R.id.btnGetText);
        btnGetText.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                TextView lbl = (TextView)
                        getActivity().findViewById(R.id.lblFragment1);
                Toast.makeText(getActivity(), lbl.getText(), 
                        Toast.LENGTH_SHORT).show();
            }
        });
    }
}

日志：

04-20 15:09:55.759: E/ActivityThread(9523): Failed to inflate
04-20 15:09:55.759: E/ActivityThread(9523): android.view.InflateException: Binary XML file line #7: Error inflating class fragment
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:282)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Activity.setContentView(Activity.java:1881)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.example.fragments.FragmentsActivity.onCreate(FragmentsActivity.java:15)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Activity.performCreate(Activity.java:5104)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2260)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2356)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.access$600(ActivityThread.java:150)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1244)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.os.Looper.loop(Looper.java:137)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.main(ActivityThread.java:5195)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.reflect.Method.invokeNative(Native Method)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.reflect.Method.invoke(Method.java:511)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
04-20 15:09:55.759: E/ActivityThread(9523):     at dalvik.system.NativeStart.main(Native Method)
04-20 15:09:55.759: E/ActivityThread(9523): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.Fragments.Fragment1: make sure class name exists, is public, and has an empty constructor that is public
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Fragment.instantiate(Fragment.java:592)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Fragment.instantiate(Fragment.java:560)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Activity.onCreateView(Activity.java:4709)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
04-20 15:09:55.759: E/ActivityThread(9523):     ... 21 more
04-20 15:09:55.759: E/ActivityThread(9523): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.Fragments.Fragment1" on path: /data/app/com.example.fragments-2.apk
04-20 15:09:55.759: E/ActivityThread(9523):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Fragment.instantiate(Fragment.java:582)
04-20 15:09:55.759: E/ActivityThread(9523):     ... 24 more

---

看起来您输入的包名有误

---

Logcat显示它找不到类

com.example.Fragments.Fragment1

。

Fragment1

的源代码显示您将包命名为

com.example.fragments

，而不是

com.example.fragments

。将包名称大写，或将其引用小写。

布局定义错误

android:name=“com.example.Fragments.Fragment1”

。应该是

android:name="com.example.fragments.Fragment1"

---

同样适用于碎片2

请将LogCat的整个堆栈跟踪贴在墙上。非常感谢

package com.example.fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class Fragment2 extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, 
            ViewGroup container, Bundle savedInstanceState) {
        //---Inflate the layout for this fragment---
        return inflater.inflate(
                R.layout.fragment2, container, false);
    }

    @Override
    public void onStart() {
        super.onStart();
        //---Button View---
        Button btnGetText = (Button)
                getActivity().findViewById(R.id.btnGetText);
        btnGetText.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                TextView lbl = (TextView)
                        getActivity().findViewById(R.id.lblFragment1);
                Toast.makeText(getActivity(), lbl.getText(), 
                        Toast.LENGTH_SHORT).show();
            }
        });
    }
}

04-20 15:09:55.759: E/ActivityThread(9523): Failed to inflate
04-20 15:09:55.759: E/ActivityThread(9523): android.view.InflateException: Binary XML file line #7: Error inflating class fragment
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:282)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Activity.setContentView(Activity.java:1881)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.example.fragments.FragmentsActivity.onCreate(FragmentsActivity.java:15)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Activity.performCreate(Activity.java:5104)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2260)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2356)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.access$600(ActivityThread.java:150)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1244)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.os.Looper.loop(Looper.java:137)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.ActivityThread.main(ActivityThread.java:5195)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.reflect.Method.invokeNative(Native Method)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.reflect.Method.invoke(Method.java:511)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
04-20 15:09:55.759: E/ActivityThread(9523):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
04-20 15:09:55.759: E/ActivityThread(9523):     at dalvik.system.NativeStart.main(Native Method)
04-20 15:09:55.759: E/ActivityThread(9523): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.Fragments.Fragment1: make sure class name exists, is public, and has an empty constructor that is public
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Fragment.instantiate(Fragment.java:592)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Fragment.instantiate(Fragment.java:560)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Activity.onCreateView(Activity.java:4709)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
04-20 15:09:55.759: E/ActivityThread(9523):     ... 21 more
04-20 15:09:55.759: E/ActivityThread(9523): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.Fragments.Fragment1" on path: /data/app/com.example.fragments-2.apk
04-20 15:09:55.759: E/ActivityThread(9523):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
04-20 15:09:55.759: E/ActivityThread(9523):     at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
04-20 15:09:55.759: E/ActivityThread(9523):     at android.app.Fragment.instantiate(Fragment.java:582)
04-20 15:09:55.759: E/ActivityThread(9523):     ... 24 more

android:name="com.example.fragments.Fragment1"