需要幫助從我的佈局中的按鈕訪問我的活動中的方法。繼續獲得NPE

Question

我使用ListView和SimpleCursorAdapter以標準方式顯示項目列表。在每個列表行中，我有一個Button視圖，以便可以觸發刪除事件。但是，當我的應用程序啓動時，我不斷收到NPE，我無法弄清楚原因。我確定我忽略了一些簡單的東西，但我不知道在哪裏。以下是我有：

MyActivity.java

public class MyActivity extends Fragment { 
    private View rootView; 
    private SwipeRefresh mySwipeRefresh; 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){ 
     rootView = inflater.inflate(R.layout.my_layout, container, false); 
     mySwipeRefresh = (SwipeRefresh)rootView.findViewById(R.id.my_swipe_refresh); 
    } 

    @Override 
    public void onViewCreated(View rootView, Bundle savedInstanceState){ 
     super.onViewCreated(rootView savedInstanceState); 
     drawTheList(); 
    } 

    public void drawTheList(){ 
     DatabaseHelpler dbHelper = new DatabaseHelper(getActivity()); 
     Cursor cursor = dbHelper.getDataCursor(); 
     String[] fromColumns = {"data01","data02","data03","data04"}; 
     int[] toViews = {R.id.view01, R.id.view02, R.id.view03, R.id.view04}; 
     SimpleCursorAdapter simpleCursorAdapter = new SimpleCursorAdapter(getContext(), R.layout.line_of_data, cursor, fromColumns, toViews, 0); 

     ListView listView = (ListView)rootView.findViewById(R.id.data_rows); 

     listView.setAdapter(simpleCursorAdapter); 

     dbHelper.close; 

     Button deleteButton = (Button)listView.findViewById(R.id.remove_item); 
     deleteButton.setOnClickListener(deleteButtonListener); 
    } 

    View.OnClickListener deleteButtonListener = new View.OnClickListener(){ 
     @Override 
     public void onClick(View view){ 
      Toast.makeText(rootView.getContext(), "message", Toast.LENGTH_LONG).show(); 
     } 
    }; 
} 

my_layout.xml

<LinearLayout> 
    <android.support.v4.widget.SwipeRefreshLayout> 
     <ListView android:id="@+id/data_rows" /> 
    </android.support.v4.widget.SwipeRefreshLayout> 
</LinearLayout> 

line_of_data

<LinearLayout android:orientation="horizontal"> 
    <TextView android:id="@+id/view01" /> 
    <TextView android:id="@+id/view02" /> 
    <TextView android:id="@+id/view03" /> 
    <TextView android:id="@+id/view04" /> 
    <LinearLayout android:orientation="horizontal"> 
     <ImageView /> 
     <Button android:id="@+id/remove_item" /> 
    </LinearLayout> 
</LinearLayout> 

NPE來自線路deleteButton.setOnClickListener(deleteButtonListener);。當我評論這一行時，應用程序啓動就好了。

我試圖用我的XML簡單android:onClick="deleteMethod"且在我的活動deleteMethod，但該方法是從來沒有可供按鈕（AndroidStudio就不會顯示該方法，當我用Ctrl +空格鍵）

什麼我錯過了嗎？

感謝

Answer 1

嘗試使用CursorAdapter您的自定義執行和bindView()方法中添加按鈕，點擊收聽

public class CustomSimpleCursorAdapter extends SimpleCursorAdapter { 

    private Context mContext;   
    private int layout; 
    private Cursor cr; 
    private final LayoutInflater inflater; 


    public CustomSimpleCursorAdapter(Context context, int layout, Cursor c, String[] from, int[] to, int flags) { 
     super(context, layout, c, from, to, flags); 
     this.layout=layout; 
     this.mContext = context; 
     this.inflater=LayoutInflater.from(context); 
     this.cr=c; 
    } 

    @Override 
    public View newView (Context context, Cursor cursor, ViewGroup parent) { 
      return inflater.inflate(layout, null); 
    } 

    @Override 
    public void bindView(View view, Context context, Cursor cursor) { 

     super.bindView(view, context, cursor); 
     Button yourButton = (Button) view.findViewById(R.id.remove_item); 
     yourButton.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       //add code 
      } 
     }); 
     } 
    } 

使用它作爲：

CustomSimpleCursorAdapter simpleCursorAdapter = new CustomSimpleCursorAdapter(getContext(), R.layout.line_of_data, cursor, fromColumns, toViews, 0);