我的片段不要調用我的ListViev的getView方法

Question

我對android開發非常陌生。我正在嘗試使用製表符（通過片段添加）來構建應用程序。在其中一個片段（Sector1）中，我試圖顯示一個ListView。這個列表已經使用UserCustomAdapter進行了填充，這是我從ArrayAdapter擴展而來的。 問題是ListView不可見，如果我嘗試填充列表，應用程序崩潰！ thx所有！

這是UserCustomAdapter.java

public class UserCustomAdapter extends ArrayAdapter<User> { 
private static final int INVISIBLE = 4; 
private static final int VISIBLE = 0; 
Context context; 
int layoutResourceId; 
ArrayList<User> data = new ArrayList<User>(); 

public UserCustomAdapter(Context context, int layoutResourceId, ArrayList<User> data) { 
    super(context, layoutResourceId, data); 

    this.layoutResourceId = layoutResourceId; 
    this.context = context; 
    this.data = data; 
} 



@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
     View row = convertView; 
     UserHolder holder = null; 

     System.out.println("@@@-getView-@@@"); 
     if (row == null) { 
     LayoutInflater inflater = ((Activity) context).getLayoutInflater(); 
     row = inflater.inflate(layoutResourceId, parent, false); 
     holder = new UserHolder(); 
     holder.textName = (TextView) row.findViewById(R.id.tv_prodotto); 
     holder.textQta = (TextView) row.findViewById(R.id.tv_qta); 
     //holder.textLocation = (TextView) row.findViewById(R.id.textView3); 
     holder.btnEdit = (ImageButton) row.findViewById(R.id.button1); 
     holder.btnDelete = (ImageButton) row.findViewById(R.id.button2); 

     row.setTag(holder); 
     } else { 
     holder = (UserHolder) row.getTag(); 
     } 

     User user = data.get(position); 
     holder.Useritem = data.get(position); 
     holder.textName.setText(user.getName()); 
     holder.textQta.setText(user.getAddress()); 
     //holder.textLocation.setText(user.getLocation()); 

     holder.btnDelete.setTag(holder.Useritem);// mi segno la posizione in modo da recuperarla poi in seguito!! 
     holder.btnEdit.setTag(holder.Useritem);// mi segno la posizione in modo da recuperarla poi in seguito!! 

     //rendo invisibili i pulsanti per la prima riga 
     if(position == 0){ 
      holder.btnDelete.setVisibility(INVISIBLE); 
      holder.btnEdit.setVisibility(INVISIBLE); 
     }else{ 
      holder.btnDelete.setVisibility(VISIBLE); 
      holder.btnEdit.setVisibility(VISIBLE); 
     } 

    holder.btnDelete.setOnClickListener(new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     // TODO Auto-generated method stub 
     Log.i("Delete Button Clicked", "**********"); 
     Toast.makeText(context, "Delete button Clicked", 
      Toast.LENGTH_LONG).show(); 

     User itemToRemove = (User)v.getTag(); 
     Sector1.userAdapter.remove(itemToRemove); 
     Sector1.userAdapter.notifyDataSetChanged(); 
    } 
    }); 

     return row; 
} 

static class UserHolder { 
    TextView textName; 
    TextView textQta; 
    //TextView textLocation; 
    ImageButton btnEdit; 
    ImageButton btnDelete; 
    User Useritem; 
} 

這是Sector1.java

public class Sector1 extends Fragment 
{ 
    private Button btnNew_order,btnAggiungi; 
    private Spinner spin_prodotto, spin_tipo; 
    private EditText EtQta; 
    ListView userList; 
    Static UserCustomAdapter userAdapter; 
    ArrayList<User> userArray = new ArrayList<User>(); 

     @Override 
     public View onCreateView(LayoutInflater inflater, 
       ViewGroup container, 
       Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.sector1, container, false); 
      userAdapter = new UserCustomAdapter(getActivity().getBaseContext(), R.layout.row, userArray); 
      userList = (ListView) rootView.findViewById(R.id.listView); 
      userList.setItemsCanFocus(false); 
      userList.setAdapter(userAdapter); 
      //userAdapter.setListAdapter(); 
      //userList.setListAdapter(userAdapter); 
      //userAdapter.getView(0, rootView, container); 


      spin_prodotto = (Spinner) rootView.findViewById(R.id.spin_prodotto); 
      spin_tipo = (Spinner) rootView.findViewById(R.id.spin_tipo); 
      btnNew_order = (Button) rootView.findViewById(R.id.btn_new_order); 
      btnAggiungi = (Button) rootView.findViewById(R.id.btn_aggiungi); 
      EtQta = (EditText) rootView.findViewById(R.id.Et_qta); 

      btnAggiungi.setEnabled(false); 

      btnNew_order.setOnClickListener(new OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        // TODO Auto-generated method stub 
        btnAggiungi.setEnabled(true); 

        Date now = new Date(); 
        SimpleDateFormat DesiredFormat = new SimpleDateFormat("dd/MM/yyyy kk:MM"); 
        String newFormat = DesiredFormat.format(now.getTime()); 

        String Order = "Ordine del:\n" +newFormat; 
//     userAdapter.add(new User(Order, "Fornitore: Passerini"));   
//     userAdapter.notifyDataSetChanged();   
       }  
      });   


      //return super.onCreateView(inflater, container, savedInstanceState); 
      return rootView; 
     } 
    public void removeItemClickHandler(final View v) { 
     User itemToRemove = (User)v.getTag(); 
     userAdapter.remove(itemToRemove); 
     userAdapter.notifyDataSetChanged(); 
    } 

}

這是我sector1.xml

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

    <LinearLayout 
     android:id="@+id/LinearLayout1" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:orientation="horizontal"> 
     <Button 
      android:id="@+id/btn_new_order" 
      style="?android:attr/buttonStyleSmall" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content"    
      android:text="@string/new_order" /> 
    </LinearLayout> 
    <LinearLayout 
     android:id="@+id/LinearLayout2" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_marginTop="50dp" 
     android:orientation="horizontal" > 

     <Spinner 
      android:id="@+id/spin_prodotto" 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:entries="@array/passerini_product" 
      android:prompt="@string/product_prompt"/> 
    </LinearLayout> 

    <LinearLayout 
     android:id="@+id/LinearLayout3" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_marginTop="120dp" 
     android:orientation="horizontal" > 

     <TextView 
      android:id="@+id/lb_tv_qta" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:textSize="10sp" 
      android:layout_alignParentLeft="true" 
      android:layout_alignParentTop="true" 
      android:text="qta:" /> 

     <EditText 
      android:id="@+id/Et_qta" 
      android:layout_width="50dp" 
      android:layout_height="wrap_content" 
      android:layout_marginLeft="3dp" 
      android:ems="2" 
      android:inputType="numberSigned|numberDecimal" 
      android:text="1" > 
      <requestFocus /> 
     </EditText>  

     <Spinner 
      android:id="@+id/spin_tipo" 
      android:layout_width="wrap_content" 
      android:layout_height="match_parent" 
      android:layout_marginLeft="3dp" 
      android:layout_weight="50" 
      android:entries="@array/type_product" /> 

     <Button 
      android:id="@+id/btn_aggiungi" 
      style="?android:attr/buttonStyleSmall" 
      android:layout_width="wrap_content" 
      android:layout_height="match_parent" 
      android:drawableLeft="@android:drawable/ic_input_add" 
      android:text="Aggiungi" /> 
    </LinearLayout> 

    <LinearLayout 
     android:id="@+id/LinearLayout5" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_marginTop="170dp" 
     android:background="#ccffcc" 
     android:orientation="horizontal" > 

     <ListView 

      android:id="@+id/listView" 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content">   
<!--    tools:listitem="@layout/row"> -->   
     </ListView> 
    </LinearLayout> 
</FrameLayout> 

這是row.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:padding="5dp" 
    tools:context=".MainActivity" > 

    <TextView 
     android:id="@+id/tv_prodotto" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentTop="true" 
     android:layout_marginLeft="50dp" 
     android:text="Prodotto" 
     android:textStyle="bold" android:textColor="#000000" /> 

    <ImageButton 
     android:id="@+id/button2" 
     android:layout_width="40dp" 
     android:layout_height="40dp" 
     android:layout_alignParentRight="true" 
     android:layout_alignParentTop="true" 
     android:focusable="false" 
     android:focusableInTouchMode="false" 
     android:src="@android:drawable/ic_menu_delete"  
     android:textColor="#0099CC" /> 

</RelativeLayout> 

這個ID我MainActivity.java

public class MainActivity extends FragmentActivity implements ActionBar.TabListener { 

     AppSectionsPagerAdapter mAppSectionsPagerAdapter; 
     ViewPager mViewPager; 

     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.activity_main); 

    // Settare il tipo di navigazione 
      mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager()); 
      final ActionBar actionBar = getActionBar(); 

      actionBar.setHomeButtonEnabled(false); 
      actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 

      mViewPager = (ViewPager) findViewById(R.id.pager); 
      mViewPager.setAdapter(mAppSectionsPagerAdapter); 
      mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { 
       @Override 
       public void onPageSelected(int position) { 
          actionBar.setSelectedNavigationItem(position); 
       } 
      }); 

      // creo icona e scritta per il primo Tab 
      Tab tab = actionBar.newTab() 
        .setText("Ordine") 
        .setTabListener(this) 
        .setIcon(R.drawable.computer); 
      actionBar.addTab(tab); 

      // creo icona e scritta per il primo Tab 
      tab = actionBar.newTab() 
        .setText("Invio") 
        .setTabListener(this) 
        .setIcon(R.drawable.email); 
      actionBar.addTab(tab); 
     } 



//public void removeItemClickHandler(final View v) { 
// User itemToRemove = (User)v.getTag(); 
// userAdapter.remove(itemToRemove); 
// userAdapter.notifyDataSetChanged(); 
// } 


     @Override 
     public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
     } 

     @Override 
     public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 

      mViewPager.setCurrentItem(tab.getPosition()); 
     } 

     @Override 
     public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
     } 


     public class AppSectionsPagerAdapter extends FragmentPagerAdapter { 

      public AppSectionsPagerAdapter(FragmentManager fm) { 
       super(fm); 
      } 

    // Il return new chiama le altre classi (i Fragment) 
      @Override 
      public Fragment getItem(int i) { 
       switch (i) { 
        case 0:      
         return new Sector1(); 
        case 1: 
         return new Sector2(); 

        default:      
         Fragment fragment = new Sector1(); 
         Bundle args = new Bundle(); 

         fragment.setArguments(args); 
         return fragment; 
       } 
      } 

    // Settare il titolo dei Sector 

      @Override 
      public int getCount() { 
       return 2; 
      } 

      public CharSequence getPageTitle(int position) { 
       String tabLabel = null; 
       switch (position) { 

       case 0: 
       tabLabel = getString(R.string.title_section1); 
       break; 

       case 1: 
       tabLabel = getString(R.string.title_section2); 
       break;    
       } 
       return tabLabel; 
      } 
     } 
    } 

Answer 1

更換

LayoutInflater inflater = ((Activity) context).getLayoutInflater(); 

與

LayoutInflater.from(context); 

在您的UserAdapter.getView（）方法中。

總是看你的日誌 - 在大多數情況下，它有助於確定崩潰原因。你認爲ClassCastException是我可以自我解釋的。當您創建將getActivity（）。getBaseContext（）傳遞給適配器的適配器時，您嘗試將適配器屬性上下文同時轉換爲Activity（適配器的第43行）。