Question

我有一个ListView，每个Listitem都有一个ImageButton，当点击时会显示一个带有两个按钮的溢出菜单。我使用的是从名为TrackedRun的对象扩展的自定义ArrayAdapter。我想引用与通过溢出菜单单击的ListItem对应的TrackedRun对象。

这是我的适配器（仅包含相关代码）：

public class HistoryListItemAdapter extends ArrayAdapter<TrackedRun> {

public interface OnOverflowButtonListener {
    void onDeleteClick(int id);
    void onEditClick(int id);
}


private Context context;
private TrackedRun currentItem;
private View rootView;
private OnOverflowButtonListener listener;
private int position;

public HistoryListItemAdapter(Context context, ArrayList<TrackedRun> items,
                              HistoryFragment historyFragment, OnOverflowButtonListener listener){
    super(context, 0, items);
    this.context = context;
    this.listener = listener;
}

@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) getContext()
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    rootView = convertView;
    currentItem = getItem(position);
    this.position = position;

    if (null == rootView) {
        rootView = inflater.inflate(
                R.layout.history_list_item,
                parent,
                false);
    }
    setOverflowMenu();

    return rootView;
}

private void setOverflowMenu(){
    final ImageButton button = (ImageButton) rootView.findViewById(R.id.overflow_icon);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View v) {

            final PopupMenu menu = new PopupMenu(getContext(), button);
            menu.getMenuInflater().inflate(R.menu.list_item_overflow, menu.getMenu());
            menu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                @Override
                public boolean onMenuItemClick(MenuItem item) {

                    switch (item.getItemId()){

                        case R.id.edit_button :
                            listener.onEditClick(currentItem.getId());
                            break;

                        case R.id.delete_button :
                            listener.onDeleteClick(currentItem.getId());
                            break;
                    }
                    return true;
                }
            });
            menu.show();
        }
    });
}

}

这是我初始化ListView（相关代码）的片段：

public class HistoryFragment extends Fragment {

private View rootView;
private HistoryListItemAdapter adapter;
private ListView listView;

public HistoryFragment(){
    //Required empty constructor.
}

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    rootView = inflater.inflate(R.layout.fragment_history, container, false);
    initListView();

    return rootView;
}

private void initListView(){
    listView = (ListView) rootView.findViewById(R.id.history_listview);
    ArrayList<TrackedRun> trackedRuns = new DatabaseHandler(getContext()).getAllTrackedRuns();
    adapter = new HistoryListItemAdapter(getContext(), trackedRuns, this, new HistoryListItemAdapter.OnOverflowButtonListener() {
        @Override
        public void onDeleteClick(int id) {
            System.out.println(id);
        }

        @Override
        public void onEditClick(int id) {
            System.out.println(id);
        }
    });
    listView.setAdapter(adapter);
    listView.setEmptyView(rootView.findViewById(R.id.empty_view));

}

private void loadRecords() {
   //Gets records from database, and reloads ListView with new records.
}

}

当我在我的适配器中调用onEditClick和onDeleteClick时，来自currentItem的id总是来自最后添加的ListItem的id，而不是被点击的id。如何获取与单击的ListItem对应的TrackedRun对象，以便获得正确的ID？

Answer 1

当你初始化每个溢出菜单时，你需要像这样传递当前项目

private void setOverflowMenu(final TrackedRun currentItem){
...
}

将private TrackedRun currentItem从全局变量更改为局部变量

Answer 2

当膨胀ListView时，<!doctype html> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <title>AngularJS Bootstrap Duallistbox example</title> <meta name="description" content=""> <meta name="viewport" content="width=device-width"> <link rel="stylesheet" href="styles/main.css"> <link rel="stylesheet" href="../bower_components/bootstrap/dist/css/bootstrap.css"> <link rel="stylesheet" href="../bower_components/bootstrap-duallistbox/src/bootstrap-duallistbox.css"> </head> <body ng-app="bsDuallistboxApp">  <div class="container" ng-controller="MainCtrl"> <select ng-model="model" ng-options="obj as obj.text for obj in list track by obj.id" multiple bs-duallistbox bootstrap2="{{ settings.bootstrap2 }}" move-on-select="{{ settings.moveOnSelect }}" preserve-selection="{{ settings.preserveSelection }}" move-selected-label="{{ settings.moveSelectedLabel }}" move-all-label="{{ settings.moveAllLabel }}" remove-selected-label="{{ settings.removeSelectedLabel }}" remove-all-label="{{ settings.removeAllLabel }}" non-selected-list-label="{{ settings.nonSelectedListLabel }}" selected-list-label="{{ settings.selectedListLabel }}" postfix="{{ settings.postfix }}" select-min-height="{{ settings.selectMinHeight }}" filter="{{ settings.filter }}" filter-values="{{ settings.filterValues }}" filter-non-selected="settings.filterNonSelected" filter-selected="settings.filterSelected" filter-placeholder="{{ settings.filterPlaceholder }}" filter-clear="{{ settings.filterClear }}" info-all="{{ settings.infoAll }}" info-filtered="{{ settings.infoFiltered }}" info-empty="{{ settings.infoEmpty }}" </select> <div class="row"> <button class="btn btn-large" ng-click="reset()">Reset</button> <button class="btn btn-large" ng-click="add()">Add</button> </div> </div> <script src="../jquery/jquery.js"></script> <script src="../angular/angular.js"></script> <script src="../bootstrap-duallistbox/src/jquery.bootstrap-duallistbox.js"> </script> <script src="../common/module.js"></script> <script src="../bootstrap/dist/js/bootstrap.js"></script> <script src="../src/directives/bsDuallistbox.js"></script> <script src="scripts/app.js"></script> <script src="scripts/controllers/main.js"></script> </body> </html>方法将被执行getView次。所以当你的ListView被夸大完成时，currentItem就是最后一个。我的建议是：

getCount()

使用位置更简单，因为您已在Activity中拥有数组。

单击按钮时，Android获取列表项的位置

2 个答案: