我有一個android片段,它有一個listview。對於那個listview,我實現了一個內部OnItemClickListener類。 發生點擊時,我將選擇保存在名爲SelectedIndex的全局變量中。內部OnItemClickListener中全局變量的問題
如果再次點擊該列表,我可以正確看到前面的選擇,所以它將正確地保存在全局變量上。
問題是當我嘗試從另一個內部類訪問同一個全局變量時,例如,一個類用於監聽點擊按鈕。總是顯示我用於初始化變量(-1)的值。
片段的代碼:
/**
* A placeholder fragment containing the view for the recentCalls list
*/
public class RecentCallsFragment extends Fragment {
private Cursor cursorAllRows;
private RecentCallsTable rcTable;
private ListView list;
private RecentCallsAdapter adapter;
Button btnDelete, btnCreditRequest, btnCreditBlock, btnSendTo;
int selectedIndex; //this is the global variable that I am using.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
rcTable = new RecentCallsTable(getActivity());
cursorAllRows = rcTable.getRecentCallsCursor();
adapter = new RecentCallsAdapter(getActivity(), cursorAllRows);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
list = (ListView) view.findViewById(R.id.listViewMain);
btnDelete = (Button) getActivity().findViewById(R.id.buttonDelete);
btnCreditRequest = (Button) getActivity().findViewById(R.id.buttonCr);
btnCreditBlock = (Button) getActivity().findViewById(R.id.buttonCRD);
list.setAdapter(adapter);
list.setOnItemClickListener(new ItemClickHandler()); //Add the inner ItemClickLister
btnSendTo = (Button) getActivity().findViewById(R.id.buttonSendTo);
btnSendTo.setOnClickListener(new DebugOnClick());//here I add the inner clicklister
return view;
}
/**
* Class that handles the one click action on the list
*/
public class ItemClickHandler implements AdapterView.OnItemClickListener{
//when there's one fast click, keep the selection on the item or remove it if already has it
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
int prevSelection = adapter.getSelectedIndex();
Toast.makeText(getActivity(), Integer.toString(selectedIndex), Toast.LENGTH_SHORT).show();
int newSelection = position;
if(prevSelection == position){
newSelection = -1;
}
selectedIndex = newSelection; //here I change the value of the global variable
adapter.setSelectedIndex(newSelection);
adapter.notifyDataSetChanged();
}
}
public class DebugOnClick implements View.OnClickListener{
public DebugOnClick(){
}
@Override
public void onClick(View view) {
Toast.makeText(getActivity(), Integer.toString(selectedIndex), Toast.LENGTH_SHORT).show(); //here I show the value of the global variable and is always -1
}
}
}
這可能是什麼問題?
那麼可以採取什麼解決方案?將內部類移到獨立類中?我在想這個,但我不知道如何與聽衆實現這一點。 – tenhsor 2014-10-01 21:04:38
我沒有看到任何外部化這些內部類的問題,一個監聽器不必是匿名的或定義爲內部類。在創建監聽器時,您應該在構造函數中提供正確的RecentCallsFragment的鏈接,它們應該共享。 – Juru 2014-10-01 21:08:10