安卓问题 照着第一行代码敲的 第14章天气app实战 在点击listview的item时 一直等待出不来结果

Question

public class MainActivity extends Activity {
//AppCompatActivity
    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 ListView listView;
    private ArrayAdapter<String> adapter;
    private CoolWeatherDB coolWeatherDB;
    private List<String> dataLits = new ArrayList<String>();
    /**
     * 省列表
     */
    private List<Province> provinceList;
    private List<City> cityList;
    private List<County> countyList;
    /**
     * 选中的省份
     */
    private Province selectedProvince;
    private City selectedCity;
    /**
     * 当前选中的级别
     */
    private int currentLevel;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.choose_area);        listView = (ListView)findViewById(R.id.list_view);
        titleText = (TextView)findViewById(R.id.title_text);
        adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,dataLits);
        listView.setAdapter(adapter);
        coolWeatherDB = coolWeatherDB.getInstance(this);        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();
                }
            }
        });
        queryProvinces();    }    /**
     * 查询全国所有的省，优先从数据库中查询，如果没有查询到再到服务气中查询
     */
    private void queryProvinces() {
        provinceList = coolWeatherDB.loadProvince();
        if(provinceList.size()>0) {
            Toast.makeText(this,"从数据库中读取",Toast.LENGTH_LONG).show();
            dataLits.clear();
            for(Province province:provinceList) {
                dataLits.add(province.getProvinceName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            titleText.setText("中国");
            currentLevel = LEVEL_PROVINCE;
        } else {
            queryFromServer(null, "province");
            Toast.makeText(this,"从服务器中读取",Toast.LENGTH_LONG).show();
        }
    }
    private void queryCities() {
        cityList = coolWeatherDB.loadCities(selectedProvince.getId());
        if(cityList.size()>0) {
            Toast.makeText(this, "数据库", Toast.LENGTH_LONG).show();
            dataLits.clear();
            for(City city : cityList){
                dataLits.add(city.getCityName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            titleText.setText(selectedProvince.getProvinceName());
            currentLevel = LEVEL_CITY;
        }else {
            queryFromServer(selectedProvince.getProvinceCode(),"city");
        }
    }
    private void queryCounties() {
        countyList = coolWeatherDB.loadConuties(selectedCity.getId());
        if(countyList.size()>0) {
            Toast.makeText(this, "数据库", Toast.LENGTH_LONG).show();
            dataLits.clear();
            for(County county : countyList){
                dataLits.add(county.getCountyName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            titleText.setText(selectedCity.getCityName());
            currentLevel = LEVEL_COUNTY;
        }else {
            queryFromServer(selectedCity.getCityCode(),"county");
        }
    }    private void queryFromServer(final String code, final String type) {        String address;
        if(!TextUtils.isEmpty(code)){
            address = "http://www.weather.com.cn/data/list3/city19.xml";
        }else {
            address = "http://www.weather.com.cn/data/list3/city.xml";
        }
        //showProgressDialog();
        HttpUtil.sendHttpRequest(address, new HttpCallbackListener() {
            @Override
            public void onFinish(String response) {
                boolean result = false;
                if ("province".equals(type)) {
                    result = Utility.handleProvincesResponse(coolWeatherDB, response);
                } else if ("city".equals(type)) {
                    result = Utility.handleCitiesResponse(coolWeatherDB,response,
                            selectedProvince.getId());
                } else if ("county".equals(type)) {
                    result = Utility.handleCountiesResponse(coolWeatherDB, response,
                            selectedCity.getId());
                }
                if (result) {
                    //通过runOnUiThread方法回到主线程处理逻辑上
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            if (type.equals("province")) {
                                queryProvinces();
                            } else if (type.equals("city")) {
                                queryCities();
                            } else if (type.equals("county")) {
                                queryCounties();
                            }
                        }
                    });
                }
            }
            @Override
            public void onError(Exception e) {
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        closeProgressDialog();
                        Toast.makeText(MainActivity.this,"加载失败，服务器挂了",Toast.LENGTH_LONG).show();
                    }
                });
            }
        });
    }    private void showProgressDialog() {
        if(progressDialog == null) {
           progressDialog = new ProgressDialog(this);
            progressDialog.setMessage("正在加载中····");
            progressDialog.setCanceledOnTouchOutside(false);
        }
        progressDialog.show();
    }    @Override
    public void onBackPressed() {
        super.onBackPressed();
        if(currentLevel==LEVEL_COUNTY){
            queryCities();
        }else if(currentLevel==LEVEL_CITY){
            queryProvinces();
        }else {
            finish();
        }
    }    private void closeProgressDialog(){
        if(progressDialog!=null){[code=java][code=java][/code][/code]
            progressDialog.dismiss();
        }
    }
}

Answer 1

无法获得数据，你从服务器上获得数据失败，是不是服务器的openID设置不对。或者接口设置不对

Answer 2

鉴于描述的“一直在加载”的情况，虽然不能debug，然是可以从请求路径开始分析。
很明显，请求省级以下数据时没有带上省的code参数。那么原因基本就是路径写错了。
查看了一下电子书的源码。
 if(!TextUtils.isEmpty(code)){
             address = "http://www.weather.com.cn/data/list3/city19.xml";
         }else {
             address = "http://www.weather.com.cn/data/list3/"+code+"city.xml";
         }
应该可以解决问题了。

Answer 3

我刚刚也是这样，首先那个接口没有过期的。我是saveCity时编码直接复制上面saveProvince的码，结果漏掉了values.put("Province_id",city.getProvinceId());希望能帮到后来者。仔细检查下query语句是否和要查询的table信息一致。