Question

我尝试使用customAdapter来填充listView，出于某种原因，当我动态添加新数据时，旧数据将被新数据替换，并且添加的新数据完全无序。这是我的自定义适配器：

public class logAdapter extends BaseAdapter {
    private ArrayList<String> kindArray = new ArrayList<String> (), logArray= new ArrayList<String> (), timeArray= new ArrayList<String> ();
    private ArrayList<Integer> viewKind= new ArrayList<Integer> ();
    private LayoutInflater inflater;

    public logAdapter(Context context) {
        inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        return kindArray.size();
    }

    public void updateData(String kind, String log, String  time, Integer view) {
        this.kindArray.add(kind);
        this.logArray.add(log);
        this.viewKind.add(view);
        this.timeArray.add(time);
        this.notifyDataSetChanged();
    }


    @Override
    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View currentView = convertView;

        if (this.viewKind.get(position) == 0)
        {
            if (currentView == null) {
                currentView = inflater.inflate(R.layout.log_list_first, parent, false);
                TextView tView = (TextView)currentView.findViewById(R.id.addr);
                tView.setText(this.logArray.get(position));
                TextView timeView = (TextView)currentView.findViewById(R.id.timeText);
                timeView.setText(this.timeArray.get(position));
            }



        }else if(this.viewKind.get(position) == 1){
            if (currentView == null) {
                currentView = inflater.inflate(R.layout.log_list_middle, parent, false);
                TextView tView = (TextView)currentView.findViewById(R.id.logMessage);
                tView.setText(this.logArray.get(position));
                TextView titleView = (TextView)currentView.findViewById(R.id.kindText);
                titleView.setText(this.kindArray.get(position));
            }

        }else if(this.viewKind.get(position) == 2){
            if (currentView == null) {
                currentView = inflater.inflate(R.layout.log_list, parent, false);
                TextView tView = (TextView)currentView.findViewById(R.id.logMessage);
                tView.setText(this.logArray.get(position));
                TextView titleView = (TextView)currentView.findViewById(R.id.kindText);
                titleView.setText(this.kindArray.get(position));
                TextView timeView = (TextView)currentView.findViewById(R.id.timeText);
                timeView.setText(this.timeArray.get(position));
            }

        }else if (this.viewKind.get(position) == 3)
        {
            if (currentView == null) {
                currentView = inflater.inflate(R.layout.log_list_last, parent, false);
                TextView tView = (TextView)currentView.findViewById(R.id.addr);
                tView.setText(this.logArray.get(position));
                TextView timeView = (TextView)currentView.findViewById(R.id.timeText);
                timeView.setText(this.timeArray.get(position));
            }

        }

        return currentView;
    }
}

我正在添加新数据，如下面的代码

public void addLog(String date, String kind, Integer view, String log)
    {
        getActivity().runOnUiThread(new Runnable(){
            public void run() {
                adapter.updateData(kind, log, date, view);
                //simpleList.smoothScrollToPosition(logArray.size());
            }  });
    }

我不明白为什么新数据无序添加以及为什么在listView中替换旧数据。

感谢您的帮助

Answer 1

迭代集合（例如Java中的列表）不在保证顺序中，但它通常是默认的OS文件目录整理顺序。您需要将列表按顺序放置为数组

最初只使用add（）方法在列表创建后输入元素

使用toArray（）返回类型＆＃34; Object＆＃34;

的数组

Object arraylist_object = namedarraylist_reference.toArray();

使用T [] toArray（T [] a）将ArrayList中的数组返回到其特定对象类型＆＃34; 的 e.g。字符串类型

String[] listedStrings = new String[namedarraylist_reference.size()];
namedarraylist_reference.toArray(listedStrings);

使用 set（int index，E element） 将元素准确替换为列表中的所需元素

namedarraylist_reference.set(3,"WHAT");
// or
namedarraylist_reference.set(7,listedStrings[4]);

在GUI小部件上调用repaint（）方法。

使用＆＃34; public＆＃34;可能会出现问题方法＆＃34;私人＆＃34;变量/对象也是如此！

自定义适配器notifyDataSetChanged替换旧数据

1 个答案: