Android：在自定义 ListView 中设置单个按钮的可见性

Question

我有一个带有自定义适配器（扩展 BaseAdapter）的 ListView，每行的布局由一个 TextView 和一个 Button 组成。创建列表后，我想更改特定按钮的可见性。

为此，我需要以编程方式访问单个行的视图。我不知道该怎么做。 This answer 提到 getView(int position)，但我找不到那个方法； getView() 需要 3 个参数。我应该将convertView 传递给getView(int position, View convertView, ViewGroup parent) 什么？

你能指出我正确的方向吗？

更新：View v = myListView.getChildAt(myListView.getFirstVisiblePosition()); 获得的视图为空。此外，myListView.getChildCount() 返回 0。

Answer 1

onItemClick 会将被单击的 ListView 中的视图传递给您。然后你可以抓住那个 View 并用它做任何你想做的事情，包括改变可见性等。

http://developer.android.com/reference/android/widget/AdapterView.OnItemClickListener.html

Answer 2

这是我在列表视图中使用的自定义适配器的示例 I，其中用户可以选择列表视图中的项目并将它们标记为删除。关键是在有视图之后添加 onClickListener。然后，您不仅可以使用它来更改视图，还可以更新适配器的数据。 希望您可以修改此代码以适合您的具体情况。

private class DeletePlayerAdapter extends ArrayAdapter<Player> {
    Context context;
    int layoutResourceId;
    ArrayList<Player> data;

    public DeletePlayerAdapter(Context context, int layout,
            ArrayList<Player> list) {
        super(context, layout, list);
        this.layoutResourceId = layout;
        this.context = context;
        this.data = list;
    }

    @Override
    public View getView(final int position, View convertView,
            ViewGroup parent) {
        View row = convertView;
        PlayerHolder holder = null;
        if (row == null) {
            LayoutInflater inflater = ((Activity) context)
                    .getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);
            holder = new PlayerHolder();
            holder.player_name = (TextView) row
                    .findViewById(R.id.player_name);
            holder.player_number = (TextView) row
                    .findViewById(R.id.player_number);
            holder.seeded_button = (ImageButton) row
                    .findViewById(R.id.delete_toggle);
            holder.player_name.setTypeface(tf);
            holder.player_number.setTypeface(tf);
            row.setTag(holder);
            players_array.get(position).marked_for_delete = false;

        } else {
            Log.d("PLAYER_ADAPTER", "NOT_NULL ROW");
            holder = (PlayerHolder) row.getTag();
        }
        holder.seeded_button.setOnClickListener(new OnClickListener() {
            private int pos = position;

            public void onClick(View v) {
                ImageButton b = (ImageButton) v;
                if (b.isSelected()) {
                    b.setSelected(false);
                    players_array.get(pos).marked_for_delete = false;
                } else {
                    b.setSelected(true);
                    players_array.get(pos).marked_for_delete = true;
                }
            }
        });
        Player p = data.get(position);
        holder.player_name.setText(p.name);
        holder.player_number.setText(String.valueOf(position+1));
        holder.seeded_button
                .setSelected(players_array.get(position).marked_for_delete);
        return row;
    }

}

static class PlayerHolder {
    TextView player_number;
    TextView player_name;
    ImageButton seeded_button;
}