Question

我真的需要一些好的提示....我已经花了几个小时调试这个（（...

public class Travel {
    public static String from, to;

    Travel(String f, String t) {
        this.from = f;
        this.to = t;
    }
}

final class NotesAdapter extendes ArrayAdapter<Travel>{
private final List<Travel> myC;

public NotesAdapter(Context context, int resource, List<Travel> myCt) {
    super(context, resource, myCt);
    this.myC = myCt;
}

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

@Override
public Travel getItem(int position) {
    return myC.get(position);
}

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

@Override
public View getView(int position, View convertView, ViewGroup adapterView) {

    Travel trv = myC.get(position);

    if (convertView == null) {
        convertView = LayoutInflater.from(getContext()).inflate(R.layout.my_lists, adapterView, false);
    }

    TextView from = (TextView)convertView.findViewById(R.id.tv_from);
    TextView to = (TextView)convertView.findViewById(R.id.tv_to);

    from.setText(trv.from);//.getMFrom()
    to.setText(trv.to);//.getMTo()

    return convertView;
    }

在NotesAdapter中，我只实现了您在此处看到的方法。然后在主活动中我启动startactivityforresult并在onactivityresults中向List对象添加元素。

List<Travel> myCities = new ArrayList<Travel>();

将List对象初始化为ArrayList（... new ArrayList＆lt;＆gt;（）...）。我也有：

mList = (ListView)findViewById(R.id.for_lists);
na = new NotesAdapter(this,R.layout.my_lists,myCities);

所以：

nCity = data.getStringExtra("content");

收集新字符串

myCities.add(new Travel("Home Town",nCity));

添加新旅行......和：

na.notifyDataSetChanged();
mList.setAdapter(na);

这是所有代码：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
    if(requestCode == MY_REQUEST_CODE){
        if(resultCode == RESULT_OK){
            nCity = data.getStringExtra("content");

                if (!myCities.contains(nCity)) {
                    myCities.add(new Travel("Home Town",nCity));
                    na.notifyDataSetChanged();

                } else {
                    Toast.makeText(this,"This City has already been added",Toast.LENGTH_LONG).show();
                }
        }
        else {
            //do something when user refused to complete action
        }

        hT.setText("Home Town");
        iB.setText(infoBar);

        na.notifyDataSetChanged();
        mList.setAdapter(na);
        mList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

            }
        });
    }
    else {
            // not my business another request
    }
 }

当我只使用一个字符串列表时，一切都很完美。 “旅行列表”的结果是列表视图中的所有视图都显示最后添加的旅行。

对于布局文件，我使用基本实现。

请帮忙...... ^ _ ^

Answer 1

在您致电na之前，

mList.setAdapter(na);永远不会设置为列表。您无需致电na.notifyDataSetChanged();

请在NotesAdapter适配器中添加一个新方法。此方法将更新数据：

public void updateData(List<Travel> myCt){
    this.myC = myCt;
}

然后更新你的代码

na.notifyDataSetChanged();
mList.setAdapter(na);

带

na.updateData(myCities);
mList.setAdapter(na);

Answer 2

问题是static

public static String from, to

Android ListView所有视图显示最后的项目数据

2 个答案: