Question

我有一个ListView，每行都有一个按钮，我在Button适配器中声明了ListView，这个Button是不可见的，但我需要更改Button视图在某些情况下可见。作为Button适配器类中的Listview声明，我无法访问它以更改其可见性。我怎么能管理它？

这是我的Adapter：

    public class MessageSimpleAdapter extends SimpleAdapter {
public String mId;
private static List<HashMap<String, String>> listMapBGMessage;
private static Context context;
private static int resource;
private GroupMadeByUserActivity _recAct;

protected static int[] resourceList;
protected static String[] fromList;


private static class ViewHolder {

    TextView[] tv_bid_group_name;
    ImageView iv_bid_group_delete;
    TextView[] tv_bid_group_comment;

    int position;
}

public MessageSimpleAdapter(Context context,
        List<HashMap<String, String>> data, int resource, String[] from,
        int[] to, GroupMadeByUserActivity recAct) {
    super(context, data, resource, from, to);

    // save the ArrayList and context for later usage
    MessageSimpleAdapter.listMapBGMessage = data;
    MessageSimpleAdapter.context = context;
    MessageSimpleAdapter.resource = resource;

    _recAct = recAct;
    resourceList = to;
    fromList = from;

}


@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // declare it final so that it could be accessed from the inner class
    final ViewHolder holder;

    if (convertView == null) {
        LayoutInflater mInflater = (LayoutInflater) MessageSimpleAdapter.context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        convertView = mInflater.inflate(MessageSimpleAdapter.resource,
                parent, false);

        holder = new ViewHolder();
        holder.tv_bid_group_name = new TextView[fromList.length];
        holder.tv_bid_group_comment = new TextView[fromList.length];

        // get the textview's from the convertView
        for (int i = 0; i < fromList.length; i++) {
            holder.tv_bid_group_name[i] = (TextView) convertView
                    .findViewById(resourceList[i]);
            holder.tv_bid_group_comment[i] = (TextView) convertView
                    .findViewById(resourceList[i]);

        }

        // get the phoneIcon and emailIcon as well from convertView
        holder.iv_bid_group_delete = (ImageView) convertView
                .findViewById(R.id.iv_bid_group_delete);



        // add a listener for phone call
        holder.iv_bid_group_delete
                .setOnClickListener(new OnClickListener() {

                    @Override
                    public void onClick(View v) {

                        GroupMadeByUserActivity.messageIdStatic = MessageSimpleAdapter.listMapBGMessage
                                .get(holder.position).get("IDMessage");

                        _recAct.new AsyncDeleteMessage().execute(GroupMadeByUserActivity.messageIdStatic);

                    }

                });

        // store it in a Tag as its the first time this view is generated
        convertView.setTag(holder);

    } else {
        /* get the View from the existing Tag */
        holder = (ViewHolder) convertView.getTag();
    }

    /* update the textView's text for this list view item/element */
    for (int i = 0; i < fromList.length; i++) {
        holder.tv_bid_group_name[i].setText(listMapBGMessage.get(position)
                .get(fromList[i]));
    }

    // store the position/index for this list view element/item
    holder.position = position;

    return convertView;
}

    }

Answer 1

您必须更改适配器getView中的可见性。检查条件并更改可见性。

Answer 2

除了在适配器中更改它之外，我没有看到其他方法。您的适配器是否知道决定的原因？如果没有，你可以在创建时传递它们。

如果您想将决定外包，您可以在getView中执行此操作：

...
boolean isVisible = MyUtil.isButtonVisible(listMapBGMessage.get(position)); // pass the object or an id
int visibility = isVisible ? View.VISIBLE : View.GONE; // GONE or INVISIBLE
holder.iv_bid_group_delete.setVisibility(visibility);

通过这种方式，您可以在public static boolean isButtonVisible(...)中集中精力，并且适配器不需要知道原因，只需做出决定。

Answer 3

如下文字：

public View getView(...) {
        ...
        holder.myBUTON.setVisibility(buttonsVisible ? View.VISIBLE : View.INVISIBLE)
        ...
    }

boolean isVisible = MyUtil.isButtonVisible（listMapBGMessage.get（位置））; //通过 object或id int visibility = isVisible？ View.VISIBLE：View.GONE; // GONE或INVISIBLE holder.iv_bid_group_delete.setVisibility（可见性）;

之后：

notifyDataSetChanged（）;

或者您可以创建一个设置Visible或Invisible按钮的方法，并在通知后查看更改。

更改列表视图在活动中的按钮可见性

3 个答案: