如何在微调器中显示所选项目?

我创建了两个微调器来显示应用程序中的数据。在第一个微调器中,列表的第一个项目始终直接显示,但在第二个微调器中,不显示任何内容,即使我单击下拉视图中的项目。有人能解释这种行为吗?

以下是两个微调器初始化的代码:

projects = new Spinner(lexs);
projectAdapter = new ProjectAdapter();
projects.setAdapter(projectAdapter);
projects.setMinimumWidth(250);
projects.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
   updateSpinners(position);                    
}

@Override
public void onNothingSelected(AdapterView<?> parent) {
   // do nothing    
}

});

projectsList = new Spinner(lexs);
projectsList.setMinimumWidth(250);
listAdapter = new ListAdapter();
projectsList.setAdapter(listAdapter);
projectsListLayer.addView(projectsList);

自旋体项目是第一个正确工作的自旋体。ProjectsList是第二个无法正常工作的微调器。下面是适配器的两个实现:

private class ProjectAdapter implements SpinnerAdapter {

        @Override
        public View getDropDownView(int position, View arg1, ViewGroup arg2) {
            TextView text = new TextView(lexs);
            text.setText(allProjects.get(position).getName());
            return text;
        }

        @Override
        public int getCount() {
            return allProjects.size();
        }

        @Override
        public Object getItem(int position) {
            return allProjects.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public int getItemViewType(int arg0) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View arg1, ViewGroup arg2) {
            TextView text = new TextView(lexs);
            text.setText(allProjects.get(position).getName());
            return text;
        }

        @Override
        public int getViewTypeCount() {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public boolean hasStableIds() {
            return false;
        }

        @Override
        public boolean isEmpty() {
            if (allProjects.size() == 0) {
                return true;
            } else {
                return false;
            }
        }

        @Override
        public void registerDataSetObserver(DataSetObserver arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void unregisterDataSetObserver(DataSetObserver observer) {
            // TODO Auto-generated method stub

        }

    }

    private class ListAdapter implements SpinnerAdapter {

        @Override
        public View getDropDownView(int position, View view, ViewGroup parent) {
            TextView text = new TextView(lexs);
            text.setText(allLists.get(position).getName());
            return text;
        }

        @Override
        public int getCount() {
            return allLists.size();
        }

        @Override
        public Object getItem(int position) {
            return allLists.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public int getItemViewType(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            TextView text = new TextView(lexs);
            text.setText(allLists.get(position).getName());
            return text;
        }

        @Override
        public int getViewTypeCount() {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public boolean hasStableIds() {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean isEmpty() {
            if (allLists.size() == 0) {
                return true;
            } else {
                return false;
            }
        }

        @Override
        public void registerDataSetObserver(DataSetObserver observer) {
            // TODO Auto-generated method stub
        }

        @Override
        public void unregisterDataSetObserver(DataSetObserver observer) {
            // TODO Auto-generated method stub
        }

    }

在这里,我附上了问题的图片:

http://www.freeimagehosting.net/image.php?7684c157b8.png