安卓 View InflateException : Binary XML file line #11 with runtime error

Question

我想为再次提出这个主题而道歉，但我试图按照我发现的任何其他 Q/A 进行操作，但没有人为我工作。

另外，我刚开始为Android编程，所以请原谅我的无知。

由于我正在研究 Fragments，所以我试图在网络上找到一些可以清楚地解释这个主题的好例子。
这是我第一次练习时遵循的网络资源

Fragment Example

阅读并复制文件中的代码后，我注意更改包名称，但在运行应用程序后，这是我收到的 LogCat:

02-12 06:02:03.838: E/AndroidRuntime(1599): java.lang.RuntimeException: Unable to start activity ComponentInfo{it.coppola.fragmentexample/it.coppola.fragmentexample.FragmentExampleActivity}: android.view.InflateException: Binary XML file line #11: Error inflating class fragment
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.os.Handler.dispatchMessage(Handler.java:102)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.os.Looper.loop(Looper.java:136)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.ActivityThread.main(ActivityThread.java:5017)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at java.lang.reflect.Method.invokeNative(Native Method)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at java.lang.reflect.Method.invoke(Method.java:515)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at dalvik.system.NativeStart.main(Native Method)
02-12 06:02:03.838: E/AndroidRuntime(1599): Caused by: android.view.InflateException: Binary XML file line #11: Error inflating class fragment
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:713)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.Activity.setContentView(Activity.java:1929)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at it.coppola.fragmentexample.FragmentExampleActivity.onCreate(FragmentExampleActivity.java:13)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.Activity.performCreate(Activity.java:5231)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
02-12 06:02:03.838: E/AndroidRuntime(1599): Caused by: java.lang.NullPointerException
02-12 06:02:03.838: E/AndroidRuntime(1599):     at it.coppola.fragmentexample.ToolbarFragment.onCreateView(ToolbarFragment.java:51)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:900)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1082)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1184)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:291)
02-12 06:02:03.838: E/AndroidRuntime(1599):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:685)

类和布局文件

FramentExampleActivity.java

package it.coppola.fragmentexample;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.Fragment;
import android.view.Menu;

public class FragmentExampleActivity extends FragmentActivity implements ToolbarFragment.ToolbarListener {

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

    public void onButtonClick(int fontsize, String text) {
        TextFragment textFragment = 
                   (TextFragment) 
                     getSupportFragmentManager().findFragmentById(R.id.text_fragment);      
                 textFragment.changeTextProperties(fontsize, text);

    }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.layout.activity_fragment_example,  menu);
    return true;
}

}

TextFragment.java

package it.coppola.fragmentexample;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class TextFragment extends Fragment {

    private static TextView textview;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
        Bundle savedInstanceState) {
          View view = inflater.inflate(R.layout.text_fragment,  container, false);
          textview = (TextView) view.findViewById(R.id.textView1);

        return view;
    }

     public void changeTextProperties(int fontsize, String text)
        {
            textview.setTextSize(fontsize);
            textview.setText(text);
        } 

}

ToolbarFrament.java

package it.coppola.fragmentexample;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;

public class ToolbarFragment extends Fragment implements OnSeekBarChangeListener {

      private static int seekvalue = 10;
      private static EditText edittext;
      ToolbarListener activityCallback;

      public interface ToolbarListener {
            public void onButtonClick(int position, String text);
      }

      @Override
      public void onAttach(Activity activity) {
            super.onAttach(activity);
            try {
                activityCallback = (ToolbarListener) activity;
            } catch (ClassCastException e) {
                throw new ClassCastException(activity.toString()
                        + " must implement ToolbarListener");
            }
        }


       @Override
        public View onCreateView(LayoutInflater inflater, 
            ViewGroup container, Bundle savedInstanceState) {
            // Inflate the layout for this fragment

            View view =  inflater.inflate(R.layout.toolbar_fragment,  container, false);

            edittext = (EditText) view.findViewById(R.id.editText1);
            final SeekBar seekbar = (SeekBar) view.findViewById(R.id.seekBar1);

            seekbar.setOnSeekBarChangeListener(this);

            final Button button = (Button) view.findViewById(R.id.button1);

            button.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    buttonClicked(v);
                }
            });

            return view;
       }

       public void buttonClicked (View view) {
           activityCallback.onButtonClick(seekvalue, edittext.getText().toString());

       }

       @Override
        public void onProgressChanged(SeekBar seekBar, int progress,
                boolean fromUser) {
           seekvalue = progress;
        }

       @Override
       public void onStartTrackingTouch(SeekBar arg0) {
           // TODO Auto-generated method stub
       }

       @Override
       public void onStopTrackingTouch(SeekBar arg0) {
           // TODO Auto-generated method stub
       }
}

activity_fragment_example.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".FragmentExampleActivity" >

    <fragment
        android:id="@+id/toolbar_fragment"
        class="it.coppola.fragmentexample.ToolbarFragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        tools:layout="@layout/toolbar_fragment" />

    <fragment
        android:id="@+id/text_fragment"
        class="it.coppola.fragmentexample.TextFragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        tools:layout="@layout/text_fragment" />

</RelativeLayout>

text_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

 <TextView
       android:id="@+id/textView1"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_centerHorizontal="true"
       android:layout_centerVertical="true"
       android:text="Fragment Two"
       android:textAppearance="?android:attr/textAppearanceLarge" />   
</RelativeLayout>

toolbar_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" 
     xmlns:tools="http://schemas.android.com/tools">

<Button
    android.id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/seekBar1"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="17dp"
    android:text="Change Text" />

<EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="16dp"
        android:ems="10"
        android:inputType="text" >
        <requestFocus />

    </EditText>

        <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/editText1"
        android:layout_marginTop="14dp" />

</RelativeLayout>

还有几个:

我确保我加载了 android-support-v4.jar 库，并且我没有以任何方式修改 AndroidManifest.xml。

感谢您愿意提供的任何帮助，感谢您的耐心等待。

Answer 1

您的工具栏 fragment 布局 XML 中存在拼写错误:

android.id="@+id/button1"

更改为android:id:

android:id="@+id/button1"

这会导致 findViewById() 返回 null 并尝试在 null 上调用 setOnClickListener()导致第 51 行出现 NPE。