android.view.InflateException - 傻瓜式 Android 应用程序开发

Question

我正在尝试通过《Android 应用程序开发傻瓜书》一书来学习一些 Android 编程。书中的一个任务是创建一个名为任务提醒的应用程序，该应用程序引入了androidfragment。根据这本书，以下代码应该创建第一个简单的 ListView :

import android.app.ListActivity;
import android.os.Bundle;
import android.util.Log;

public class ReminderListActivity extends ListActivity {

@Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.reminder_list);    
    }

}

提醒列表如下所示:

<?xml version="1.0" encoding="utf-8"?>

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
   android:name="com.holtkoe.android.birthdaytimer.ReminderListFragment"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent" />

ReminderListFragment 类如下:

import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;

public class ReminderListFragment extends ListFragment {

   private ListAdapter mAdapter;

    @Override
    public void onActivityCreated(Bundle savedInstanceState){
        super.onActivityCreated(savedInstanceState);

        String[] items = new String[] {"Foo","Bar","Fizz","Bin"};

        mAdapter = new ArrayAdapter<String>(getActivity(), R.layout.reminder_row,  R.id.text1, items);
        setListAdapter(mAdapter);

     }
  }

最后是reminder_row:

<?xml version="1.0" encoding="utf-8"?>
<TextView 
    android:id="@+id/text1"
    xmlns:android="http://schemas.android.com/apk/res/android"    
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"/>

我尝试在模拟设备和智能手机上运行它，但总是得到以下内容

09-26 22:44:53.270: D/AndroidRuntime(2493): Shutting down VM
09-26 22:44:53.270: W/dalvikvm(2493): threadid=1: thread exiting with uncaught   exception (group=0x412d8930)
09-26 22:44:53.290: E/AndroidRuntime(2493): FATAL EXCEPTION: main
09-26 22:44:53.290: E/AndroidRuntime(2493): java.lang.RuntimeException: Unable to  start activity   ComponentInfo{com.holtkoe.android.birthdaytimer/com.holtkoe.android.birthdaytimer.ReminderListActivity}: android.view.InflateException: Binary XML file line #3: Error inflating class fragment
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2245)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2299)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.ActivityThread.access$700(ActivityThread.java:150)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1280)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.os.Looper.loop(Looper.java:137)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.ActivityThread.main(ActivityThread.java:5283)  
09-26 22:44:53.290: E/AndroidRuntime(2493):     at java.lang.reflect.Method.invokeNative(Native Method)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at java.lang.reflect.Method.invoke(Method.java:511)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at dalvik.system.NativeStart.main(Native Method)
09-26 22:44:53.290: E/AndroidRuntime(2493): Caused by: android.view.InflateException: Binary XML file line #3: Error inflating class fragment
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:710)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.view.LayoutInflater.inflate(LayoutInflater.java:467)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:364)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.Activity.setContentView(Activity.java:1930)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at com.holtkoe.android.birthdaytimer.ReminderListActivity.onCreate(ReminderListActivity.java:14)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.Activity.performCreate(Activity.java:5283)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)   
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2209)
09-26 22:44:53.290: E/AndroidRuntime(2493):     ... 11 more
09-26 22:44:53.290: E/AndroidRuntime(2493): Caused by: android.app.Fragment$InstantiationException: Trying to instantiate a class com.holtkoe.android.birthdaytimer.ReminderListFragment that is not a Fragment
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.Fragment.instantiate(Fragment.java:584)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.Fragment.instantiate(Fragment.java:560)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.app.Activity.onCreateView(Activity.java:4864)
09-26 22:44:53.290: E/AndroidRuntime(2493):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:686)
09-26 22:44:53.290: E/AndroidRuntime(2493):     ... 20 more
09-26 22:44:53.290: E/AndroidRuntime(2493): Caused by: java.lang.ClassCastException
09-26 22:44:53.290: E/AndroidRuntime(2493):     ... 24 more

说实话，我迷路了(显然甚至不是一个假人)...我阅读了 Android 开发人员引用中的 fragment ，那里给出的示例看起来与书中写的非常相似，但是，出于某种原因，那里是通货膨胀问题。

非常感谢您的帮助!谢谢大家!

Answer 1

我认为您缺少 onCreateView 方法来膨胀您的 View 。您仍然需要在 fragment 内膨胀 View 。

即

import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;

public class ReminderListFragment extends ListFragment {
    private ListAdapter mAdapter;

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

    @Override
    public void onActivityCreated(Bundle savedInstanceState){
        super.onActivityCreated(savedInstanceState);

        String[] items = new String[] {"Foo","Bar","Fizz","Bin"};

        mAdapter = new ArrayAdapter<String>(getActivity(), R.layout.reminder_row,
                                            R.id.text1, items);
        setListAdapter(mAdapter);

    }
}

编辑:

这是您可以尝试的另一件事，在您给我的示例中，在 xml 中， fragment 位于框架布局内，您可以尝试将 xml 更改为如下所示:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent" android:layout_height="match_parent">

    <fragment xmlns:android="http://schemas.android.com/apk/res/android"
        android:name="com.holtkoe.android.birthdaytimer.ReminderListFragment"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

</FrameLayout>

尝试使用或不使用 onCreateView 来查看所有选项及其行为方式。