Question

我正在制作一个消息传递应用程序。到目前为止，一切都运行良好，但是当新消息从另一个活动到达时，我还没有想出如何更新列表视图。我希望如果消息到达，如果用户在消息传递屏幕上，它将更新列表视图以便他们显示新消息。

实际上，用户必须重新打开应用程序才能查看新消息。我现在想弄清楚如何自动刷新或更新当前列表视图。

我的MessageAdapter如下：

public class MessageAdapter extends BaseAdapter {
// This is the custom adapter for displaying the labdetails in listview of a
// dialog inside the activity
String picsDownloadFolder = Environment.getExternalStorageDirectory() + "/"
        + "Congress" + "/", imageLinkBuilder;
private Activity activity;

private LayoutInflater inflater = null;
private List<MessageModel> data;
int myPosition;
int totalNumAttackers = 0, totalNumDamage = 0;
public Boolean bb[];
int element;
DbUtils dbutil;

File LocImageFile;
WindowManager.LayoutParams WMLP;
List<UserModel> notificationList = new ArrayList<UserModel>();

public MessageAdapter(Activity a, List<MessageModel> notifyList) {

    activity = a;

    inflater = (LayoutInflater) activity
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    dbutil = new DbUtils();
    // notificationList = notifyList;
    data = notifyList;

}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return data.size();
}

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return position;
}

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub

    ViewHolder viewHolder;
 MessageModel array = data.get(position);
    if (convertView == null) {
        viewHolder = new ViewHolder();
        convertView = inflater.inflate(R.layout.message_item, null);
        viewHolder.left =(LinearLayout)convertView.findViewById(R.id.left);
        viewHolder.right =(LinearLayout)convertView.findViewById(R.id.right);
        viewHolder.txt1 = (TextView) convertView
                .findViewById(R.id.textView1);
        viewHolder.txt3 = (TextView) convertView
                .findViewById(R.id.textView3);
        viewHolder.txt2 = (TextView) convertView
                .findViewById(R.id.textView2);
        viewHolder.txt4 = (TextView) convertView
                .findViewById(R.id.textView4);

        convertView.setTag(viewHolder);


    } else {
        // prevent recycling of views
        viewHolder = (ViewHolder) convertView.getTag();
    }
    if (array.gettype().equals("received")) {
        viewHolder.right.setVisibility(View.INVISIBLE);
        viewHolder.left.setVisibility(View.VISIBLE);
        viewHolder.txt1.setText(array.getmsg());
        viewHolder.txt3.setText(array.getdate());
    } if (array.gettype().equals("sent")) {
        viewHolder.left.setVisibility(View.INVISIBLE);
        viewHolder.right.setVisibility(View.VISIBLE);
        viewHolder.txt2.setText(array.getmsg());
        viewHolder.txt4.setText(array.getdate());
    }

    return convertView;
}

// view holder class
public static class ViewHolder {

LinearLayout left,right;
TextView txt1,txt3,txt2,txt4;

}

 }

我尝试过使用：

mListView.setAdapter(mAdapter);

但它会继续强制关闭应用程序。

Answer 1

致电

mAdapter.notifyDataSetChanged();

如何使用其他活动的自定义适配器更新列表视图？

1 个答案: