java - 使用自定义适配器将项目添加到自定义 ListView

Question

我有一个自定义适配器 (ArrayAdapter)，我想在代码中动态添加项目。

我的 ArrayAdapter 看起来像这样:

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class ChatList extends ArrayAdapter<ChatListItem> {

Context context;
int layoutResourceId;
ChatListItem data[] = null;

public ChatList(Context context, int layoutResourceId, ChatListItem[] data) {
    super(context, layoutResourceId, data);
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.data = data;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    ChatHolder holder = null;
    ChatListItem entry = data[position];

    if (row == null) {
        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new ChatHolder();
        holder.txtText = (TextView) row.findViewById(R.id.txtText);
        holder.txtUser = (TextView) row.findViewById(R.id.txtUser);
        holder.txtVersion = (TextView) row.findViewById(R.id.txtVersion);
        holder.txtZeit = (TextView) row.findViewById(R.id.txtZeit);

        row.setTag(holder);

    } else {
        holder = (ChatHolder) row.getTag();
    }

    holder.txtText.setText(entry.text);
    holder.txtUser.setText(entry.user);
    holder.txtVersion.setText(entry.v);
    holder.txtZeit.setText(entry.time);

    return row;
}

static class ChatHolder {
    TextView txtText;
    TextView txtUser;
    TextView txtVersion;
    TextView txtZeit;
}
}

我想在此代码中添加项目:

LoadChatData bdl = new LoadChatData(new OnTaskComplete() {
                @Override
                public void onTaskCompleted(ChatListItem[] url, int id) {
                    currid = id;
                    for (ChatListItem i : url) {
                        if (chatList != null) {
                            chatList.add(i);
                        }
                    }
                }
            });

有办法做到这一点吗？问题是我收到此错误消息:

02-16 11:17:57.287: W/System.err(24997): java.lang.UnsupportedOperationException
02-16 11:17:57.287: W/System.err(24997):    at java.util.AbstractList.add(AbstractList.java:404)
02-16 11:17:57.287: W/System.err(24997):    at java.util.AbstractList.add(AbstractList.java:425)
02-16 11:17:57.287: W/System.err(24997):    at android.widget.ArrayAdapter.add(ArrayAdapter.java:179)
02-16 11:17:57.287: W/System.err(24997):    at de.tecfriends.vbtsplash2013.ActivityNewChat$3$1.onTaskCompleted(ActivityNewChat.java:108)
02-16 11:17:57.287: W/System.err(24997):    at de.tecfriends.vbtsplash2013.LoadChatData.doInBackground(LoadChatData.java:45)
02-16 11:17:57.287: W/System.err(24997):    at de.tecfriends.vbtsplash2013.LoadChatData.doInBackground(LoadChatData.java:1)
02-16 11:17:57.287: W/System.err(24997):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
02-16 11:17:57.287: W/System.err(24997):    at java.util.concurrent.FutureTask.run(FutureTask.java:234)
02-16 11:17:57.287: W/System.err(24997):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
02-16 11:17:57.287: W/System.err(24997):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
02-16 11:17:57.287: W/System.err(24997):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
02-16 11:17:57.287: W/System.err(24997):    at java.lang.Thread.run(Thread.java:856)

Answer 1

您不应该将项目直接添加到适配器中。将它们添加到传递给适配器的数据数组中(创建适配器时，将此数组传递给构造函数)，然后调用 adapter.notifyDataSetChanged()。