基于Geolocator的Custom ListAdapter更新

Question

我有一个listview，它从服务器上取下数据并显示。显示的数据很好。我也可以从服务器收集纬度，经度值。 但是列表适配器在显示列表后没有更新列表中的反向地理定位地址。这是代码。由于代码是出于我的业务目的，我无法直接显示其他类。但我肯定答案是在本课程中请帮助：

public class CustomListViewAdapter extends BaseAdapter
{
    LayoutInflater inflater;
    List<ListViewItem> items;
    double currentLAT, currentLONG;

    public CustomListViewAdapter(Activity context, List<ListViewItem> items) {
        super();

        this.items = items;
        this.inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

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

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

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        ViewHolder holder = new ViewHolder();
        holder.position = position;

        ListViewItem item = items.get(position);

        View vi=convertView;

        if(convertView==null)
            vi = inflater.inflate(R.layout.item_row, null);

        ImageView imgThumbnail = (ImageView) vi.findViewById(R.id.imgThumbnail);
        TextView txtTitle = (TextView) vi.findViewById(R.id.txtTitle);
        TextView txtSubTitle = (TextView) vi.findViewById(R.id.txtSubTitle);
        holder.tLocation = (TextView) vi.findViewById(R.id.tukxiLocation);
        imgThumbnail.setImageResource(item.ThumbnailResource);

        txtTitle.setText(item.Title);
        txtSubTitle.setText(item.SubTitle);
        currentLAT = item.currentLAT;
        currentLONG = item.currentLONG;


        ReverseG thetask = new ReverseG(position, holder);
        thetask.execute();

        return vi;
    }



    private class ReverseG extends AsyncTask<Void, Void, String> {
        private int mPosition;
        private ViewHolder mHolder;
        String addressString = "";
        private TransitList tl = new TransitList();


        public ReverseG(int position, ViewHolder holder){
            mPosition = position;
            mHolder = holder;
        }

        @Override
        protected String doInBackground(Void... arg0){

            try {
                Geocoder gc = new Geocoder(tl.getApplicationContext(), Locale.getDefault());
                List<Address> addressList = gc.getFromLocation(currentLAT, currentLONG, 1);
                StringBuilder add = new StringBuilder();
                if (addressList != null && addressList.size() > 0) {
                    Address address = addressList.get(0);

                    int noOfMaxAddressLine = address
                            .getMaxAddressLineIndex();
                    if (noOfMaxAddressLine > 0) {
                        for (int i = 0; i < address
                                .getMaxAddressLineIndex() - 1; i++) {
                            add.append(address.getAddressLine(i)).append(
                                    " ");
                        }
                        addressString = "Near " + add.toString();
                    }
                }
            } catch (Exception e) {

                addressString = "";
            }

            return addressString;
        }

        @Override
        protected void onPostExecute(String result){

            if(mHolder.position == mPosition){
                mHolder.tLocation.setText(result);
            }
        }
    }

    private static class ViewHolder {
        public int position;
        public TextView tLocation;
    }
}

我在这里使用TransitList类对象将其作为上下文传递，因为列表是在该类中生成的。

编辑：我在上下文中进行了必要的更改。现在它显示每个列表项的地址都很好。 但是在加载地址时，它会逐一显示第一个项目上的所有地址，然后更新剩余的项目。这是更新后的代码：

package com.transit.tukxi;

/**
 * Created by sachin on 05/09/13.
 */
import java.util.List;
import java.util.Locale;

import com.transit.tukxi.TransitList.ListViewItem;

import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.os.AsyncTask;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;


public class CustomListViewAdapter extends BaseAdapter
{
    LayoutInflater inflater;
    List<ListViewItem> items;
    double currentLAT, currentLONG;
    Context c;

    public CustomListViewAdapter(Activity context, List<ListViewItem> items) {
        super();
        this.c = context;
        this.items = items;
        this.inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

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

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

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        ViewHolder holder = new ViewHolder();
        holder.position = position;

        ListViewItem item = items.get(position);

        View vi=convertView;

        if(convertView==null)
            vi = inflater.inflate(R.layout.item_row, null);

        ImageView imgThumbnail = (ImageView) vi.findViewById(R.id.imgThumbnail);
        TextView txtTitle = (TextView) vi.findViewById(R.id.txtTitle);
        TextView txtSubTitle = (TextView) vi.findViewById(R.id.txtSubTitle);
        holder.tLocation = (TextView) vi.findViewById(R.id.tukxiLocation);
        imgThumbnail.setImageResource(item.ThumbnailResource);

        txtTitle.setText(item.Title);
        txtSubTitle.setText(item.SubTitle);
        holder.currentLAT = item.currentLAT;
        holder.currentLONG = item.currentLONG;


        ReverseG thetask = new ReverseG(position, holder);
        thetask.execute();

        return vi;
    }



    private class ReverseG extends AsyncTask<Void, Void, String> {
        private int mPosition;
        private ViewHolder mHolder;
        String addressString = "";

        public ReverseG(int position, ViewHolder holder){
            mPosition = position;
            mHolder = holder;
        }

        @Override
        protected String doInBackground(Void... arg0){

            try {
                Geocoder gc = new Geocoder(c, Locale.getDefault());
                List<Address> addressList = gc.getFromLocation(mHolder.currentLAT, mHolder.currentLONG, 1);
                StringBuilder add = new StringBuilder();
                if (addressList != null && addressList.size() > 0) {
                    Address address = addressList.get(0);

                    int noOfMaxAddressLine = address
                            .getMaxAddressLineIndex();
                    if (noOfMaxAddressLine > 0) {
                        for (int i = 0; i < address
                                .getMaxAddressLineIndex() - 1; i++) {
                            add.append(address.getAddressLine(i)).append(
                                    " ");
                        }
                        addressString = "Near " + add.toString();
                    }
                }
            } catch (Exception e) {

                addressString = "";
            }

            return addressString;
        }

        @Override
        protected void onPostExecute(String result){

            if(mHolder.position == mPosition){
                mHolder.tLocation.setText(result);
            }
        }
    }

    private static class ViewHolder {
        public int position;
        public double currentLAT, currentLONG;
        public TextView tLocation;
    }
}