小豪的CoolWeather实战
公羊英达
这里给出小豪的实战项目github地址
https://github.com/qinjiahao666/CoolWeather
备注：
在这里应该首先告诫读者，当你的程序出现报错的时候，很大一定程度上是你的代码出现了问题，比如：代码写错了、少写了、多写了等等都会引起程序出现问题。极少部分情况是因为书的年代久远，有些东西更新换代了，会导致你的程序出现问题。那么在这个时候，就需要多看几篇博客，多去请教那些比你厉害的学长。
在这里要给读者一些建议
照着书敲代码的时候不存在什么逻辑问题，因为那又不是你的逻辑，只存在细心不细心的问题，不要自以为是的想当然，这才是最重要的，当然在照着书写代码的时候，你是会学到读者的逻辑的，这也是一种学习。只要认真一点，就能少走很多坑！
我的问题
- 遍历的城市信息无法显示
package com.example.administrator.coolweather;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.example.administrator.coolweather.db.City;
import com.example.administrator.coolweather.db.County;
import com.example.administrator.coolweather.db.Province;
import com.example.administrator.coolweather.util.HttpUtil;
import com.example.administrator.coolweather.util.Utility;
import org.litepal.crud.DataSupport;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.Response;
public class ChooseAreaFragment extends Fragment {
public static final int LEVEL_PROVINCE = 0;
public static final int LEVEL_CITY = 1;
public static final int LEVEL_COUNTY = 2;
private ProgressDialog progressDialog;
private TextView titleText;
private Button backButton;
private ListView listView;
private ArrayAdapter<String> adapter;
private List<String> dataList = new ArrayList<>();
/*
**省列表
*/
private List<Province> provinceList;
/*
****市列表
*/
private List<City> cityList;
/*
**县列表
*/
private List<County> countyList;
/*
***选中的省份
*/
private Province selectedProvince;
/*
****选中的城市
*/
private City selectedCity;
/*
*****当前选中的级别
*/
private int currentLevel;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.choose_area,container,false);
titleText = (TextView) view.findViewById(R.id.title_text);
backButton = (Button) view.findViewById(R.id.back_button);
listView = (ListView) view.findViewById(R.id.list_view);
adapter = new ArrayAdapter<>(getContext(),android.R.layout.simple_list_item_1,
dataList);
listView.setAdapter(adapter);
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
if(currentLevel == LEVEL_PROVINCE){
selectedProvince = provinceList.get(position);
queryCities();
}
else if(currentLevel == LEVEL_CITY){
selectedCity = cityList.get(position);
queryCounties();
}
else if(currentLevel == LEVEL_COUNTY){
String weatherId = countyList.get(position).getWeatherId();
if(getActivity() instanceof MainActivity) {
Intent intent = new Intent(getActivity(), WeatherActivity.class);
intent.putExtra("weather_id", weatherId);
startActivity(intent);
getActivity().finish();
}
else if(getActivity() instanceof WeatherActivity){
WeatherActivity activity = (WeatherActivity) getActivity();
activity.drawerLayout.closeDrawers();
activity.swipeRefresh.setRefreshing(true);
activity.requestWeather(weatherId);
}
}
}
});
backButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(currentLevel == LEVEL_COUNTY){
queryCities();
}
else if(currentLevel == LEVEL_CITY){
queryProvinces();
}
}
});
queryProvinces();
}
/*
*******查询全国所有的省，优先从数据库中查，如果没有再到服务器上查询
*/
private void queryProvinces(){
titleText.setText("中国");
backButton.setVisibility(View.GONE);
provinceList = DataSupport.findAll(Province.class);
if(provinceList.size() > 0){
dataList.clear();
for(Province province : provinceList){
dataList.add(province.getProvinceName());
}
adapter.notifyDataSetChanged();
listView.setSelection(0);
currentLevel = LEVEL_PROVINCE;
}
else{
String address = "http://guolin.tech/api/china";
queryFromServer(address,"province");
}
}
/*
***查询选中省内所有的市，优先从数据库中查，如果没有再到服务器上查询
*/
private void queryCities(){
titleText.setText(selectedProvince.getProvinceName());
backButton.setVisibility(View.VISIBLE);
cityList = DataSupport.where("provinceid = ?",String.valueOf(
selectedProvince.getId())).find(City.class);
if(cityList.size() > 0){
dataList.clear();
for(City city : cityList){
dataList.add(city.getCityName());
}
adapter.notifyDataSetChanged();
listView.setSelection(0);
currentLevel = LEVEL_CITY;
}
else{
int provinceCode = selectedProvince.getProvinceCode();
String address = "http://guolin.tech/api/china/" + provinceCode;
queryFromServer(address,"city");
}
}
/*
*******查询选中市内所有的县，优先从数据库中查，如果没有再到服务器上查询
*/
private void queryCounties(){
titleText.setText(selectedCity.getCityName());
backButton.setVisibility(View.VISIBLE);
countyList = DataSupport.where("cityid = ?",String.valueOf(
selectedCity.getId())).find(County.class);
if(countyList.size() > 0){
dataList.clear();
for(County county : countyList){
dataList.add(county.getCountyName());
}
adapter.notifyDataSetChanged();
listView.setSelection(0);
currentLevel = LEVEL_COUNTY;
}
else{
int provinceCode = selectedProvince.getProvinceCode();
int cityCode = selectedCity.getCityCode();
String address = "http://guolin.tech/api/china/"+provinceCode+"/"+cityCode;
queryFromServer(address,"county");
}
}
/*
******根据传入的地址和类型从服务器上查询省市县数据
*/
private void queryFromServer(String address,final String type){
showProgressDialog();
HttpUtil.sendOkHttpRequest(address, new Callback() {
@Override
public void onFailure(Call call, IOException e) {
//通过runOnUiThread()方法回到主线程处理逻辑
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
closeProgressDialog();
Toast.makeText(getContext(),"加载失败",Toast.LENGTH_SHORT).show();
}
});
}
@Override
public void onResponse(Call call, Response response) throws IOException {
String responseText = response.body().string();
boolean result = false;
if("province".equals(type)){
result = Utility.handleProvinceResponse(responseText);
}
else if("city".equals(type)){
result = Utility.handleCityResponse(responseText,
selectedProvince.getId());
}
else if("county".equals(type)){
result = Utility.handleCountyResponse(responseText,
selectedCity.getId());
}
if(result){
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
closeProgressDialog();
if("province".equals(type)){
queryProvinces();
}
else if("city".equals(type)){
queryCities();
}
else if("county".equals(type)){
queryCounties();
}
}
});
}
}
});
}
/*
*****显示进度对话框
*/
private void showProgressDialog(){
if(progressDialog == null){
progressDialog = new ProgressDialog(getActivity());
progressDialog.setMessage("正在加载...");
progressDialog.setCanceledOnTouchOutside(false);
}
progressDialog.show();
}
/*
***关闭进度对话框
*/
private void closeProgressDialog(){
if(progressDialog != null){
progressDialog.dismiss();
}
}
}
像这种情况就不是因为你的代码出现问题，因为你的代码没有问题，那么问题在哪呢？
https://blog.csdn.net/yonbor605/article/details/82223882 这个网址会给你想要的答案，并得到解决。
/ 新版本的手机模拟器不能访问Http协议，需要设置请求，详情见博客。
https://blog.csdn.net/yonbor605/article/details/82223882
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