持有人TextView觸發器nullPointerException

我在適配器中定義持有者，但每次我試圖引用其元素時，我都會得到NullPointerException。持有人TextView觸發器nullPointerException

這裏是適配器：

private class StableArrayAdapter extends ArrayAdapter<event> { 
    private Context context; 
    private List<event> mylist; 

    public StableArrayAdapter(Context context, List<event> mylist) { 
     super(context, R.layout.histlist, mylist); 
     this.context = context; 
     this.mylist = mylist; 
    } 

    public class ViewHolder { 
     public TextView amountHold; 
     public TextView typeHold; 
     public TextView DateHold; 
    } 

    public View getView(int position, View convertView, ViewGroup parent) { 
     View vi = convertView; 
     if (vi == null) { 
      final ViewHolder holder = new ViewHolder(); 
      LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      vi = inflater.inflate(R.layout.histlist, null); 
      Log.d("DeBuG9","DeBuG9"); 
      holder.amountHold = (TextView) findViewById(R.id.hlamount); 
Log.d("DeBuG10","DeBuG10"+holder.amountHold.getText().toString()); 
      holder.DateHold = (TextView) findViewById(R.id.hldate); 
      holder.typeHold = (TextView) findViewById(R.id.hltype); 
      vi.setTag(holder); 
     } 
     ViewHolder holder = (ViewHolder) vi.getTag(); 
     final event e = mylist.get(position); 
     Log.d("DeBuG","DeBuG713"+e.getAmount().toString()+e.getDate()+e.getType()); 
     holder.amountHold.setText(e.getAmount().toString()+"€"); 
     holder.DateHold.setText(e.getDate()); 
     holder.typeHold.setText(e.getType()); 
     return vi; 
    } 
}

這裏是我的名單佈局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="horizontal" > 
<TextView 
    android:id="@+id/hltype" 
    android:layout_weight="1" 
    android:layout_width="fill_parent" 
    android:text="f" 
    android:layout_height="wrap_content"/> 
<TextView 
    android:id="@+id/hldate" 
    android:layout_weight="1" 
    android:text="f" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"/> 
<TextView 
    android:id="@+id/hlamount" 
    android:layout_weight="1" 
    android:text="f" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"/> 
</LinearLayout>

我注意到，每次我想引用holder.amoutHold（如與DEBUG10）我得到一個NPE。的

 vi = inflater.inflate(R.layout.histlist, null); 
     Log.d("DeBuG9","DeBuG9"); 
     holder.amountHold = (TextView) findViewById(R.id.hlamount);

來源

2014-01-23 Pclaverie

來源

2014-01-23 12:03:58 Blackbelt

我選擇這個作爲答案，因爲這個問題是明確解釋 – Pclaverie

使用此

 vi = inflater.inflate(R.layout.histlist, null); 
     Log.d("DeBuG9","DeBuG9"); 
     holder.amountHold = (TextView)vi.findViewById(R.id.hlamount); // this is main

相反，你必須使用視圖你充氣檢索其內容。所以，你必須寫 vi.findViewById對於屬於histlist

來源

2014-01-23 12:03:31 Prachi

我的上帝...很明顯...新鮮的外觀總是很好採取:) Thx很 – Pclaverie

// try to replcae this peace of code and let me know still have stuff. 

public View getView(int position, View convertView, ViewGroup parent) { 
     ViewHolder holder; 
     if (convertView == null) { 
      holder = new ViewHolder(); 
      LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      vi = inflater.inflate(R.layout.histlist, null,false); 
      holder.amountHold = (TextView) findViewById(R.id.hlamount); 
      holder.DateHold = (TextView) findViewById(R.id.hldate); 
      holder.typeHold = (TextView) findViewById(R.id.hltype); 
      vi.setTag(holder); 
     }else{ 
      holder = (ViewHolder) vi.getTag(); 
     } 
     final event e = mylist.get(position); 
     holder.amountHold.setText(e.getAmount().toString()+"€"); 
     holder.DateHold.setText(e.getDate()); 
     holder.typeHold.setText(e.getType()); 
     return vi; 
}

來源

2014-01-23 12:08:14

在你getview方法，我將改變PLZ檢查這個我覺得有幫助的埃弗特視圖。

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

      if (convertView == null) { 
       holder = new ViewHolder(); 
       LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
       convertView = inflater.inflate(R.layout.histlist, null); 
       Log.d("DeBuG9","DeBuG9"); 
       holder.amountHold = (TextView) convertView.findViewById(R.id.hlamount); 
    Log.d("DeBuG10","DeBuG10"+holder.amountHold.getText().toString()); 
       holder.DateHold = (TextView) convertView.findViewById(R.id.hldate); 
       holder.typeHold = (TextView) convertView.findViewById(R.id.hltype); 
       vi.setTag(holder); 
      }else{ 
      holder = (ViewHolder) convertView.getTag(); 
      }final event e = mylist.get(position); 
      Log.d("DeBuG","DeBuG713"+e.getAmount().toString()+e.getDate()+e.getType()); 
      holder.amountHold.setText(e.getAmount().toString()+"€"); 
      holder.DateHold.setText(e.getDate()); 
      holder.typeHold.setText(e.getType()); 
      return convertView; 
     }

來源

2014-01-23 12:16:03 Sanket990

持有人TextView觸發器nullPointerException

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