Android NullPointerException在調用虛擬方法時Context.getResource（）

我有一個任務，使用相對佈局爲名爲todo_item.xml的這個類添加一個名爲「ToDoItem」的類的對象視圖。我剛開始學習android編程和我不知道爲什麼我得到以下錯誤。Android NullPointerException在調用虛擬方法時Context.getResource（）

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference

我的代碼看起來像這樣，有更多的類特定功能，但我已經跳過它們使問題代碼更加明顯。

public class ToDoListAdapter extends BaseAdapter { 

private final List<ToDoItem> mItems = new ArrayList<ToDoItem>(); 
private final Context mContext; 
LayoutInflater mInflater; 

private static final String TAG = "Lab-UserInterface"; 

public ToDoListAdapter(Context context) { 

    mContext = context; 
    mInflater = LayoutInflater.from(context); 


}// Create a View for the ToDoItem at specified position 
// Remember to check whether convertView holds an already allocated View 
// before created a new View. 
// Consider using the ViewHolder pattern to make scrolling more efficient 
// See: http://developer.android.com/training/improving-layouts/smooth- scrolling.html 

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

    // TODO - Get the current ToDoItem 
    final ToDoItem toDoItem = (ToDoItem) getItem(position); 


    // TODO - Inflate the View for this ToDoItem 
    // from todo_item.xml 


    convertView = mInflater.inflate(R.layout.todo_item,parent,false); 

    RelativeLayout itemLayout = (RelativeLayout) convertView.findViewById(R.id.RelativeLayout1); 

    // Fill in specific ToDoItem data 
    // Remember that the data that goes in this View 
    // corresponds to the user interface elements defined 
    // in the layout file 

    // TODO - Display Title in TextView 
    final TextView titleView = new TextView(null); 
    titleView.setText(toDoItem.getTitle());

來源

2015-07-21 Marib Sultɐn

你應該張貼從logcat的一個完整的堆棧跟蹤，所以我們可以看到這行有NullPointerException異常。 – Karakuri

試試這個在您的getView

convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.todo_item, parent, false);

無需mInflater = LayoutInflater.from(context)

來源

2015-07-21 17:41:39

Android NullPointerException在調用虛擬方法時Context.getResource（）

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