阵列适配器不工作

我想使用阵列适配器来填充我的列表视图。我建立了一个POJO类的对象数组列表到数组适配器。当我尝试通过传递对象的数组列表来实例化arrayadapter类时，我在执行SETADAPTER行时gettin空指针异常。阵列适配器不工作

请指导我解决这个

private void initialize() {  
    listView=(ListView)findViewById(R.id.lvOpenTicketList); 

    POJO_Ticket pojo_Ticket; 
    ArrayList<POJO_Ticket> ticketArray = new ArrayList<POJO_Ticket>(); 

    for(int i=0;i<openTicketList.size();i++){ 
     pojo_Ticket = new POJO_Ticket(openTicketList.get(i)); 
     ticketArray.add(pojo_Ticket);  
     Log.i("OpenTicket","i = " + Integer.toString(i)); 
    } 
     Log.i("OpenTicket","ticketArray " + ticketArray.size()); 


     adapterTicketList=new AdapterTicketList(this, ticketArray); 
     listView.setAdapter(adapterTicketList); 
     listView.setOnItemClickListener(this);  
}

public class AdapterTicketList extends ArrayAdapter<POJO_Ticket> { 
Context context; 
ArrayList<POJO_Ticket> ticketArray; 
LayoutInflater vi; 

public AdapterTicketList(Context context , ArrayList<POJO_Ticket> ticketArray) {  
    super(context, 0, ticketArray);  
    this.ticketArray = new ArrayList<POJO_Ticket>();  
    this.ticketArray.addAll(ticketArray); 
    this.context =context; 
    Log.i("AdapterTicketList"," ticket id : " + ticketArray.get(0).getTicketObject().getId()); 
    vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    } 

private class ViewHolder { 
    TextView tvTicketID; 
    TextView tvCreationHour; 
    TextView tvTableNumber; 
    TextView tvAmount;  
    } 

public View getView(final int position, View convertView, ViewGroup parent) {  
    ViewHolder holder;  
    if (convertView == null) { 
     holder = new ViewHolder();     
     convertView = vi.inflate(R.layout.rowticket, null); 
     holder.tvTicketID = (TextView) convertView.findViewById(R.id.tvTicketID); 
     holder.tvCreationHour = (TextView) convertView.findViewById(R.id.tvCreationHour); 
     holder.tvTableNumber = (TextView) convertView.findViewById(R.id.tvTableNumber); 
     holder.tvAmount = (TextView) convertView.findViewById(R.id.tvQuantity); 
     convertView.setTag(holder); 
    } else { 
     holder = (ViewHolder) convertView.getTag(); 
    }  
    Log.i("AdapterTicketList"," ticket id : " + ticketArray.get(position).getTicketObject().getId()); 
    holder.tvTicketID.setText(ticketArray.get(position).getTicketObject().getId()) ; 
    holder.tvCreationHour.setText(ticketArray.get(position).getTicketObject().getCreationHour()) ; 
    holder.tvTableNumber.setText(ticketArray.get(position).getTicketObject().getTableNumber()) ; 
    holder.tvAmount.setText(Double.toString(ticketArray.get(position).getTicketObject().getTotalAmount())) ; 
    return convertView; 
    }

}

01-08 22:11:13.707: W/dalvikvm(7284): threadid=1: thread exiting with uncaught exception (group=0x2b542210) 
01-08 22:11:13.717: E/AndroidRuntime(7284): FATAL EXCEPTION: main 
01-08 22:11:13.717: E/AndroidRuntime(7284): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.restaurent/com.example.restaurent.OpenTicketList}: java.lang.NullPointerException 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.ActivityThread.access$600(ActivityThread.java:127) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.os.Handler.dispatchMessage(Handler.java:99) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.os.Looper.loop(Looper.java:137) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.ActivityThread.main(ActivityThread.java:4441) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at java.lang.reflect.Method.invokeNative(Native Method) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at java.lang.reflect.Method.invoke(Method.java:511) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at dalvik.system.NativeStart.main(Native Method) 
01-08 22:11:13.717: E/AndroidRuntime(7284): Caused by: java.lang.NullPointerException 
01-08 22:11:13.717: E/AndroidRuntime(7284): at com.example.restaurent.OpenTicketList.initialize(OpenTicketList.java:67) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at com.example.restaurent.OpenTicketList.onCreate(OpenTicketList.java:48) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.Activity.performCreate(Activity.java:4465) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 
01-08 22:11:13.717: E/AndroidRuntime(7284): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931) 
01-08 22:11:13.717: E/AndroidRuntime(7284): ... 11 more

来源

2013-01-08 user1822729

请发表您的logcat的错误。但它看起来列表'listView'为空，所以这意味着您当前的布局没有ID为'lvOpenTicketList'的ListView ... – Sam

但我将对象提供给适配器...当我试图打印大小（ticketArray 。尺寸（））; ）它显示为40.问题应该在arrayAdapter的getView中 – user1822729

NullPointerException意味着您试图从null变量引用方法或成员，在本例中为'null.setAdapter（）'。因此，请将您传递给'setContentView（）'（或类似方法）的布局发布。 – Sam

Caused by: java.lang.NullPointerException 
    at com.example.restaurent.OpenTicketList.initialize(OpenTicketList.java:67)

一个NullPointerException异常意味着你正试图从一个空引用的方法或成员变量，在这种情况下为null.setAdapter()。

因此，这意味着当前的布局没有一个ListView id为lvOpenTicketList ...

来源

2013-01-08 18:11:46 Sam

阵列适配器不工作

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