问通过添加按钮，ListView setOnItemClickListener不工作

EN

    private ArrayList<String> userIDArr = null;
    private ArrayList<String> userNameArr = null;
    private DatabaseHelper dbHelper = null;
    private ListView userListView=null; 


    public void onCreate(Bundle savedInstanceState) 
        {
          super.onCreate(savedInstanceState);         
          setContentView(R.layout.list_view);         
          dbHelper = new DatabaseHelper(this.getApplicationContext());        
          Map<String,ArrayList<String>> displayMap = dbHelper.getUserListToDisplay();
          userIDArr = displayMap.get("UserID");
          userNameArr = displayMap.get("FirstName1");           


          userListView = (ListView) findViewById(R.id.listView2);
          userListView.setAdapter(new UserListAdapter(this,userIDArr));


          userListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
              @Override
              public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {

                  Toast.makeText(usersListActivity.this,
                            "Item in position " + position + " clicked", Toast.LENGTH_LONG).show();
              }
            });
     }


    public class UserListAdapter extends ArrayAdapter<String>
    {
        Activity context;
        public UserListAdapter(Activity context, ArrayList<String> names) {
            super(context, R.layout.list_item, names);
            this.context = context;
        }
        private class ViewHolder {
            public TextView UserNameAndID;
            public TextView Description;
            public Button  UploadBtn;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder;
            View rowView = convertView;
            if (rowView == null) {
                LayoutInflater inflater = context.getLayoutInflater();
                rowView = inflater.inflate(R.layout.list_item, null, true);
                holder = new ViewHolder();
                holder.UserNameAndID = (TextView) rowView.findViewById(R.id.User_detailsTxt);
                holder.Description = (TextView) rowView.findViewById(R.id.User_status);
                holder.UploadBtn = (Button) rowView.findViewById(R.id.uploadbutton);
                holder.UploadBtn.setOnClickListener(new View.OnClickListener() {  

                        public void onClick(View v) {  
                        Toast.makeText(usersListActivity.this," Button clicked",Toast.LENGTH_SHORT).show();
                        }   
                    }); 
                    rowView.setTag(holder);
            } else {
                holder = (ViewHolder) rowView.getTag();
            }
            String s = userNameArr.get(position)+","+userIDArr.get(position);
            holder.UserNameAndID.setText(s);
            holder.Description.setText("U r in middle");
            return rowView;
        }
    }
}`