Question

我是一个Android新手..我正在使用光标适配器和listview，它有一个切换按钮和textview ...当我点击切换按钮时，我需要获取点击事件和项目的位置清单..

我看到很多线程，但我找不到适合我的完美解决方案......

最后我决定在bindview中设置位置并尝试在点击事件中检索它..但是当我在click事件中访问holder.position时，我得到空指针异常。

请帮助我这些家伙。非常感谢

public class CalendarListAdapter extends CursorAdapter implements OnClickListener{


protected static class RowViewHolder {
    public TextView mTitle;
    public ToggleButton mButton;
    public int position;
}

    protected ListView calListView;


    @SuppressWarnings("deprecation")
    public CalendarListAdapter(Context context, Cursor c) {
        super(context, c);
        // TODO Auto-generated constructor stub

    }


    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        // TODO Auto-generated method stub
        TextView title = (TextView) view.findViewById(R.id.calendarName);
        System.out.println("cursor details"
                + cursor.getString(cursor.getColumnIndex(cursor
                        .getColumnName(1))));
        title.setText(cursor.getString(cursor.getColumnIndex(cursor
                .getColumnName(1))));
        Log.d("click position " , "position is " +cursor.getPosition() );
        ToggleButton button = (ToggleButton) view.findViewById(R.id.silentToggle);
        button.setOnClickListener(this);
        Log.d("click position " , "position is " +cursor.getPosition() );
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        // TODO Auto-generated method stub
        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(context.LAYOUT_INFLATER_SERVICE);

        View calendarListView = inflater.inflate(R.layout.calendar_list_item, null);

        RowViewHolder rowView = new RowViewHolder();
        rowView.mTitle = (TextView)calendarListView.findViewById(R.id.calendarName);
        rowView.mButton = (ToggleButton) calendarListView.findViewById(R.id.silentToggle);
        rowView.position = cursor.getPosition();

        rowView.mTitle.setOnClickListener(titleOnClickListener);
        rowView.mButton.setOnClickListener(buttonOnClickListener);

        return calendarListView;
    }

    @Override
    public void onClick(View view) {
        // TODO Auto-generated method stub

        Log.d("item clicked", "clicked" );
        RowViewHolder holder = (RowViewHolder)view.getTag();
        int position = holder.position;
        Log.d("common  clicked", "clicked -" +position );


    }

    private OnClickListener titleOnClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            RowViewHolder holder = (RowViewHolder)v.getTag();
            int position = holder.position;
            Log.d("title clicked", "clicked -" +position );
        }
    };

    private OnClickListener buttonOnClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            RowViewHolder holder = (RowViewHolder)v.getTag();
            int position = holder.position;
            Log.d("button clicked", "clicked -" +position );

        }
    };

}

Answer 1

为了能够使用v.getTag（），你需要两件事。在newView中你需要做

calendarListView.setTag(rowView);

并且在bindView中你还需要将正确的数据插入到持有者中：

rowView.position = cursor.getPosition(); // (same as in newView)

要使所有这一切协同工作，您还需要确保您正在执行getTag（）的视图是您执行setTag的视图。

在你的情况下，这意味着在newView中执行此操作：

rowView.mTitle.setTag(rowView);
rowView.mButton.setTag(rowView);

根本不使用RowViewHolder可能会更简单。而是这样做：

在bindView中：

int pos = cursor.getPosition();
title.setTag(pos);
button.setTag(pos);

然后在你的OnClickListeners中

Integer pos = (Integer) v.getTag();

祝你好运！

Answer 2

上面的答案，setTag和getTag对我来说效果很好，但不知怎的，我意识到标签并不总能带来正确的数字。检查后，我发现我的newView函数工作太多次，这就是为什么我的所有标签都是“0”。如果你有这个问题，请检查 here寻求解决方案。

使用cursorAdapter获取按钮的项目位置在listview内单击

2 个答案: