InflateException trên phương thức inflater.inflate() gọi

Question

Tôi tiếp tục nhận được một InflateException khi cố gắng thổi phồng chế độ xem trong lớp MenuAdapter của mình. Tôi đã bao quanh mã phiền hà trong một khối try-catch và nhận được tin nhắn báo lỗi:

liên kết đến toàn bộ dự án:

https://docs.google.com/file/d/0B2Iwl4UysxOMa3E5a1l2SHZwOG8/edit?usp=sharing

dòng

tập tin XML Binary # 1: Lỗi Lạm phát lớp

đây là mã:

package com.example.sidemenututorial; 

import android.content.Context; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.BaseAdapter; 
import android.widget.ImageView; 
import android.widget.TextView; 

public class MenuListAdapter extends BaseAdapter { 

    // Fields ----------------------------------------------------------------- 
    private Context context; 
    private String[] titles; 
    private String[] subtitles; 
    private int[] icons; 
    private LayoutInflater inflater; 

    // Constructor ------------------------------------------------------------ 
    public MenuListAdapter(
      Context context, 
      String[] titles, 
      String[] subtitles, 
      int[] icons){ 
     this.context = context; 
     this.titles = titles; 
     this.subtitles = subtitles; 
     this.icons = icons; 
     inflater = (LayoutInflater)context.getSystemService(
       Context.LAYOUT_INFLATER_SERVICE); 
    } 

    // Accessors -------------------------------------------------------------- 
    @Override 
    public int getCount(){ 
     return titles.length; 
    } 
    @Override 
    public Object getItem(int position){ 
     return titles[position]; 
    } 
    @Override 
    public long getItemId(int position){ 
     return position; 
    } 

    // Methods ---------------------------------------------------------------- 
    public View getView(int position, View convertView, ViewGroup parent){ 

     ViewHolder viewHolder; 

     // Only inflate the view if convertView is null 
     if (convertView == null){ 
      viewHolder = new ViewHolder(); 
      convertView = inflater.inflate(
        R.layout.drawer_list_item, parent, false); 
      viewHolder.txtTitle = (TextView)convertView.findViewById(
        R.id.title); 
      viewHolder.txtSubtitle = (TextView)convertView.findViewById(
        R.id.subtitle); 
      viewHolder.imgIcon = (ImageView)convertView.findViewById(
        R.id.icon); 

      // This is the first time this view has been inflated, 
      // so store the view holder in its tag fields 
      convertView.setTag(viewHolder); 
     } else { 
      viewHolder = (ViewHolder)convertView.getTag(); 
     } 

     // Set the views fields as needed 
     viewHolder.txtTitle.setText(titles[position]); 
     viewHolder.txtSubtitle.setText(subtitles[position]); 
     viewHolder.imgIcon.setImageResource(icons[position]); 

     return convertView; 
    } 

    // Classes ---------------------------------------------------------------- 
    static class ViewHolder { 
     TextView txtTitle; 
     TextView txtSubtitle; 
     ImageView imgIcon; 
    } 

} 

And here is the view it is trying to inflate, the drawer_list_item.xml: 

     <LinearLayout 
     xmlns:android="http://schemas.android.com/apk/res/android" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:background="?android:color/darker_gray" 
      android:orientation="horizontal" 
      style="?attr/dropdownListPreferredItemHeight" > 

     <ImageView 
      android:id="@+id/icon" 
      android:layout_width="wrap_content" 
      android:layout_height="match_parent" 
      android:adjustViewBounds="true"/> 

     <LinearLayout 
      android:layout_width="wrap_content" 
      android:layout_height="match_parent" 
      android:gravity="center_vertical|left" 
      android:orientation="vertical"> 

      <TextView 
       android:id="@+id/title" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:ellipsize="end" 
       android:singleLine="true" 
       style="?attr/spinnerDropDownItemStyle"/> 
      <TextView 
       android:id="@+id/subtitle" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:ellipsize="end" 
       android:singleLine="true" 
       android:textAppearance="?attr/textAppearanceSmall" 
       style="?attr/spinnerDropDownItemStyle"/> 

     </LinearLayout>  

    </LinearLayout> 

Và đây là mã khách hàng đó đang kêu gọi các bộ chuyển đổi menu:

 package com.example.sidemenututorial; 

    import android.content.res.Configuration; 
    import android.os.Bundle; 
    import android.support.v4.app.ActionBarDrawerToggle; 
    import android.support.v4.app.Fragment; 
    import android.support.v4.app.FragmentTransaction; 
    import android.support.v4.view.GravityCompat; 
    import android.support.v4.widget.DrawerLayout; 
    import android.view.View; 
    import android.widget.AdapterView; 
    import android.widget.ListView; 

    import com.actionbarsherlock.app.SherlockFragmentActivity; 
    import com.actionbarsherlock.view.MenuItem; 

    public class MainActivity extends SherlockFragmentActivity { 

     // Fields ----------------------------------------------------------------- 
     private DrawerLayout drawerLayout; 
     private ListView drawerList; 
     private ActionBarDrawerToggle drawerToggle; 
     private MenuListAdapter menuAdapter; 
     private int[] icons; 
     private Fragment fragment1; 
     private Fragment fragment2; 
     private Fragment fragment3; 
     private CharSequence drawerTitle; 
     private CharSequence title; 
     private final String[] titles = new String[]{ 
       "Title Fragment #1", 
       "Title Fragment #2", 
       "Title Fragment #3" 
     }; 
     private final String[] subtitles = new String[]{ 
       "Subtitle Fragment #1", 
       "Subtitle Fragment #2", 
       "Subtitle Fragment #3" 
     }; 

     // Lifecycle Callbacks ---------------------------------------------------- 
     @Override 
     protected void onCreate(Bundle savedInstanceState) { 

      // Base implemenation 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.activity_main); 

      // Instantiate the fragments 
      fragment1 = new Fragment1(); 
      fragment2 = new Fragment2(); 
      fragment3 = new Fragment3(); 

      // Get the title from this activity 
      title = drawerTitle = getTitle(); 

      // Get the icons from the drawables folder 
      icons = new int[]{ 
        R.drawable.action_about, 
        R.drawable.action_settings, 
        R.drawable.collections_cloud 
      }; 

      // Get the drawer layout from the XML file and the ListView inside it 
      drawerLayout = (DrawerLayout)findViewById(R.id.drawer_layout); 
      drawerList = (ListView)findViewById(R.id.listview_drawer); 

      // Set a custom shadow over that overlays the main content 
      // when the drawer opens 
      drawerLayout.setDrawerShadow(
        R.drawable.drawer_shadow, GravityCompat.START); 

      // Pass the string arrays to the MenuListAdapter, set the drawer 
      // list adapter to it and set up its click listener 
      menuAdapter = new MenuListAdapter(
        MainActivity.this, titles, subtitles, icons); 
      drawerList.setAdapter(menuAdapter); 
      drawerList.setOnItemClickListener(new DrawerItemClickListener()); 

      // Enable the action bar to have up navigation 
      getSupportActionBar().setHomeButtonEnabled(true); 
      getSupportActionBar().setDisplayHomeAsUpEnabled(true); 

      // Allow the the action bar to toggle the drawer 
      drawerToggle = new ActionBarDrawerToggle(
        this, 
        drawerLayout, 
        R.drawable.ic_drawer, 
        R.string.drawer_open, 
        R.string.drawer_close){ 

       public void onDrawerClosed(View view){ 
        super.onDrawerClosed(view); 
       } 
       public void onDrawerOpened(View view){ 
        getSupportActionBar().setTitle(drawerTitle); 
        super.onDrawerOpened(view); 
       } 
      }; 
      drawerLayout.setDrawerListener(drawerToggle); 

      // If this is the first time opening this activity, 
      // start with loading fragment #1 
      if (savedInstanceState == null){ 
       selectItem(0); 
      }  

     } 

     // Methods ---------------------------------------------------------------- 
     @Override 
     public boolean onOptionsItemSelected(MenuItem item){ 

      // If the user has pressed the action bar icon 
      if (item.getItemId() == android.R.id.home){ 

       // If the drawer is open, close it; vice versa 
       if (drawerLayout.isDrawerOpen(drawerList)){ 
        drawerLayout.closeDrawer(drawerList); 
       } else { 
        drawerLayout.openDrawer(drawerList); 
       } 
      } 

      // Finish by letting the super class do the rest 
      return super.onOptionsItemSelected(item); 

     } 
     @Override 
     protected void onPostCreate(Bundle savedInstanceState){ 

      // Call the super implementation and synchronize the drawer 
      super.onPostCreate(savedInstanceState); 
      drawerToggle.syncState(); 

     } 
     @Override 
     public void onConfigurationChanged(Configuration newConfig){ 

      // Call the super implemenation on this activity 
      // and the drawer toggle object 
      super.onConfigurationChanged(newConfig); 
      drawerToggle.onConfigurationChanged(newConfig); 

     } 
     private void selectItem(int position){ 

      // Create a new fragment transaction and start it 
      FragmentTransaction fragTran = getSupportFragmentManager() 
              .beginTransaction(); 

      // Locate the position selected replace the content view 
      // with the fragment of the number selected 
      switch (position){ 
       case 0:{ 
        fragTran.replace(R.id.content_frame, fragment1); 
        break; 
       } 
       case 1:{ 
        fragTran.replace(R.id.content_frame, fragment2); 
        break; 
       } 
       case 2:{ 
        fragTran.replace(R.id.content_frame, fragment3); 
        break; 
       } 
      } 

      // Commit the transaction and close the drawer 
      fragTran.commit(); 
      drawerList.setItemChecked(position, true); 
      drawerLayout.closeDrawer(drawerList); 

     } 
     public void setTitle(CharSequence title){ 

      // Save the passed in title and set the action bar title 
      this.title = title; 
      getSupportActionBar().setTitle(title); 

     } 

     // Classes ---------------------------------------------------------------- 
     private class DrawerItemClickListener 
     implements ListView.OnItemClickListener{ 

      @Override 
      public void onItemClick(
        AdapterView<?> parent, 
        View view, 
        int position, 
        long id) { 

       // When clicked, select open the appropriate fragment 
       selectItem(position); 

      } 

     } 

    } 

Và một bản ghi của vụ tai nạn:

09-26 16:45:43.081: D/AndroidRuntime(1121): Shutting down VM 
09-26 16:45:43.081: W/dalvikvm(1121): threadid=1: thread exiting with uncaught exception (group=0x409961f8) 
09-26 16:45:45.561: E/AndroidRuntime(1121): FATAL EXCEPTION: main 
09-26 16:45:45.561: E/AndroidRuntime(1121): java.lang.NullPointerException 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at com.example.sidemenututorial.MenuListAdapter.getView(MenuListAdapter.java:73) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.AbsListView.obtainView(AbsListView.java:2033) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.ListView.makeAndAddView(ListView.java:1772) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.ListView.fillDown(ListView.java:672) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.ListView.fillFromTop(ListView.java:732) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.ListView.layoutChildren(ListView.java:1625) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.AbsListView.onLayout(AbsListView.java:1863) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.View.layout(View.java:11180) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.ViewGroup.layout(ViewGroup.java:4203) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:672) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.View.layout(View.java:11180) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.ViewGroup.layout(ViewGroup.java:4203) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.FrameLayout.onLayout(FrameLayout.java:431) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.View.layout(View.java:11180) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.ViewGroup.layout(ViewGroup.java:4203) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1399) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.View.layout(View.java:11180) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.ViewGroup.layout(ViewGroup.java:4203) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.widget.FrameLayout.onLayout(FrameLayout.java:431) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.View.layout(View.java:11180) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.ViewGroup.layout(ViewGroup.java:4203) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1468) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2418) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.os.Handler.dispatchMessage(Handler.java:99) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.os.Looper.loop(Looper.java:137) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at android.app.ActivityThread.main(ActivityThread.java:4340) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at java.lang.reflect.Method.invokeNative(Native Method) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at java.lang.reflect.Method.invoke(Method.java:511) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
09-26 16:45:45.561: E/AndroidRuntime(1121):  at dalvik.system.NativeStart.main(Native Method) 
09-26 16:45:45.593: D/dalvikvm(1121): GC_CONCURRENT freed 191K, 3% free 14296K/14599K, paused 12ms+8ms 

Answer 1

Sử dụng một ViewHolder

http://developer.android.com/training/improving-layouts/smooth-scrolling.html

.210

Thay đổi getView của bạn để

public View getView(int position, View convertView, ViewGroup parent){ 

    ViewHolder vh; 
    if(convertView==null) 
    { 
     vh = new ViewHolder(); 
     convertView = inflater.inflate(
       R.layout.drawer_list_item, parent, false); 
     vh.txtTitle = (TextView) convertView.findViewById(R.id.title); 
     vh.txtSubtitle = (TextView) convertView.findViewById(R.id.subtitle); 
     vh.imgIcon = (ImageView) convertView.findViewById(R.id.icon); 

     convertView.setTag(vh); 
    } else { 
    vh = (ViewHolder) convertView.getTag(); 
    } 
    vh.txtTitle.setText(titles[position]); 
    vh.txtSubtitle.setText(subtitles[position]); 
    vh.imgIcon.setImageResource(icons[position]); 

    return convertView; 
    } 
static class ViewHolder 
{ 
TextView txtTitle,txtSubtitle; 
ImageView imgIcon; 
} 

Cũng di chuyển dưới đây để xây dựng. Tuyên bố này như một thành viên lớp LayoutInflater inflater

Trong constructor của bạn

inflater = (LayoutInflater)context.getSystemService(
       Context.LAYOUT_INFLATER_SERVICE); 

Edit:

Trong drawer_list_item.xml

Thay đổi

android:background="?android:color/darker_gray" 

để

android:background="@android:color/darker_gray" 

Answer 2

Khi bạn gặp Lỗi khi tăng cấp lớp, bạn phải tìm sự cố trong XML trước tiên.

Trong trường hợp của bạn, sự cố nằm trong bố cục drawer_list_item của bạn. Trong gốc linearLayout của bạn, ký tự "?" gây ra nó với android: background = "? Android: color/darker_gray" hàng.