点击返回活动和刷新(三)

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="#484E61" >

        <Button
            android:id="@+id/switch_city"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_centerVertical="true"
            android:layout_marginLeft="10dp"
            android:background="@drawable/home" />

        <TextView
            android:id="@+id/city_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:textColor="#fff"
            android:textSize="24sp" />

        <Button
            android:id="@+id/refresh_weather"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="10dp"           
            android:background="@drawable/refresh" />
    </RelativeLayout>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="#27A5F9" >

        <TextView
            android:id="@+id/publish_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_marginRight="10dp"
            android:layout_marginTop="10dp"
            android:textColor="#FFF"
            android:textSize="18sp" />

        <LinearLayout
            android:id="@+id/weather_info_layout"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/current_date"
                android:layout_width="wrap_content"
                android:layout_height="40dp"
                android:gravity="center"
                android:textColor="#FFF"
                android:textSize="18sp" />

            <TextView
                android:id="@+id/weather_desp"
                android:layout_width="wrap_content"
                android:layout_height="60dp"
                android:layout_gravity="center_horizontal"
                android:gravity="center"
                android:textColor="#FFF"
                android:textSize="40sp" />

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="60dp"
                android:layout_gravity="center_horizontal"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/temp1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_vertical"
                    android:textColor="#FFF"
                    android:textSize="40sp" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_vertical"
                    android:layout_marginLeft="10dp"
                    android:layout_marginRight="10dp"
                    android:text="~"
                    android:textColor="#FFF"
                    android:textSize="40sp" />

                <TextView
                    android:id="@+id/temp2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_vertical"
                    android:textColor="#FFF"
                    android:textSize="40sp" />
            </LinearLayout>
        </LinearLayout>
    </RelativeLayout>

</LinearLayout>

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.text.TextUtils;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;



public class WeatherActivity extends Activity implements OnClickListener {
    private LinearLayout weatherInfoLayout;
    /**
     * 用于显示城市名 第 14 章 进入实战，开发酷欧天气 533
     */
    private TextView cityNameText;
    /**
     * 用于显示发布时间
     */
    private TextView publishText;
    /**
     * 用于显示天气描述信息
     */
    private TextView weatherDespText;
    /**
     * 用于显示气温1
     */
    private TextView temp1Text;
    /**
     * 用于显示气温2
     */
    private TextView temp2Text;
    /**
     * 用于显示当前日期
     */
    private TextView currentDateText;
    /**
     * 切换城市按钮
     */
    private Button switchCity;
    /**
     * 更新天气按钮
     */
    private Button refreshWeather;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.weather_layout);
        // 初始化各控件
        weatherInfoLayout = (LinearLayout) findViewById(R.id.weather_info_layout);
        cityNameText = (TextView) findViewById(R.id.city_name);

        publishText = (TextView) findViewById(R.id.publish_text);
        weatherDespText = (TextView) findViewById(R.id.weather_desp);
        temp1Text = (TextView) findViewById(R.id.temp1);
        temp2Text = (TextView) findViewById(R.id.temp2);
        currentDateText = (TextView) findViewById(R.id.current_date);

        switchCity = (Button) findViewById(R.id.switch_city);
        refreshWeather = (Button) findViewById(R.id.refresh_weather);

        String countyCode = getIntent().getStringExtra("county_code");
        if (!TextUtils.isEmpty(countyCode)) {
            // 有县级代号时就去查询天气
            publishText.setText("同步中...");
            weatherInfoLayout.setVisibility(View.INVISIBLE);
            cityNameText.setVisibility(View.INVISIBLE);
            queryWeatherCode(countyCode);
        } else {
            // 没有县级代号时就直接显示本地天气
            showWeather();
        }
        switchCity.setOnClickListener(this);
        refreshWeather.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.switch_city:
            Intent intent = new Intent(this, ChooseAreaActivity.class);
            intent.putExtra("from_weather_activity", true);
            startActivity(intent);
            finish();
            break;

        case R.id.refresh_weather:
            publishText.setText(" 同步中...");
            SharedPreferences prefs = PreferenceManager
                    .getDefaultSharedPreferences(this);
            String weatherCode = prefs.getString("weather_code", "");
            if (!TextUtils.isEmpty(weatherCode)) {
                queryWeatherInfo(weatherCode);
            }
            break;
        default:
            break;
        }
    }

    /**
     * 查询县级代号所对应的天气代号。
     */
    private void queryWeatherCode(String countyCode) {
        String address = "http://www.weather.com.cn/data/list3/city"
                + countyCode + ".xml";
        queryFromServer(address, "countyCode");
    }

    /**
     * 查询天气代号所对应的天气。
     */
    private void queryWeatherInfo(String weatherCode) {
        String address = "http://www.weather.com.cn/data/cityinfo/"
                + weatherCode + ".html";
        queryFromServer(address, "weatherCode");
    }

    /**
     * 根据传入的地址和类型去向服务器查询天气代号或者天气信息。
     */
    private void queryFromServer(final String address, final String type) {
        HttpUtil.sendHttpRequest(address, new HttpCallbackListener() {
            @Override
            public void onFinish(final String response) {
                if ("countyCode".equals(type)) {
                    if (!TextUtils.isEmpty(response)) {
                        // 从服务器返回的数据中解析出天气代号
                        String[] array = response.split("\\|");
                        if (array != null && array.length == 2) {
                            String weatherCode = array[1];
                            queryWeatherInfo(weatherCode);
                        }
                    }
                } else if ("weatherCode".equals(type)) {

                    // 处理服务器返回的天气信息
                    Utility.handleWeatherResponse(WeatherActivity.this,
                            response);
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            showWeather();
                        }
                    });
                }
            }

            @Override
            public void onError(Exception e) {
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        publishText.setText("同步失败");
                    }
                });
            }
        });
    }

    /**
     * 从SharedPreferences文件中读取存储的天气信息，并显示到界面上。
     */
    private void showWeather() {
        SharedPreferences prefs = PreferenceManager
                .getDefaultSharedPreferences(this);
        cityNameText.setText(prefs.getString("city_name", ""));
        temp1Text.setText(prefs.getString("temp1", ""));
        temp2Text.setText(prefs.getString("temp2", ""));
        weatherDespText.setText(prefs.getString("weather_desp", ""));
        publishText.setText("今天" + prefs.getString("publish_time", "") + "发布");
        currentDateText.setText(prefs.getString("current_date", ""));
        weatherInfoLayout.setVisibility(View.VISIBLE);
        cityNameText.setVisibility(View.VISIBLE);
    }
}

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.text.TextUtils;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;


public class ChooseAreaActivity extends Activity {
    public static final int LEVEL_PROVINCE = 0;
public boolean isFromWeatherActivity;
    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> dataList = new ArrayList<String>();
    /**
     * 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;

    private City selectedCity;

    private int currentLevel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        isFromWeatherActivity = getIntent().getBooleanExtra("from_weather_activity", false);
        SharedPreferences prefs = PreferenceManager
                .getDefaultSharedPreferences(this);
        if (prefs.getBoolean("city_selected", false) && !isFromWeatherActivity) {
            Intent intent = new Intent(this, WeatherActivity.class);
            startActivity(intent);
            finish();
            return;
        }
        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, dataList);
        listView.setAdapter(adapter);
        coolWeatherDB = CoolWeatherDB.getInstance(this);
        listView.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> arg0, View view, int index,
                    long arg3) {
                if (currentLevel == LEVEL_PROVINCE) {
                    selectedProvince = provinceList.get(index);
                    queryCities();
                } else if (currentLevel == LEVEL_CITY) {
                    selectedCity = cityList.get(index);
                    queryCounties();
                } else if (currentLevel == LEVEL_COUNTY) {
                    String countyCode = countyList.get(index).getCountyCode();
                    Intent intent = new Intent(ChooseAreaActivity.this,
                            WeatherActivity.class);
                    intent.putExtra("county_code", countyCode);
                    startActivity(intent);
                    finish();
                }
            }
        });
        queryProvinces(); // 加载省级数据
    }

    /**
     * 查询全国所有的省，优先从数据库查询，如果没有查询到再去服务器上查询。
     */
    private void queryProvinces() {
        provinceList = coolWeatherDB.loadProvinces();
        if (provinceList.size() > 0) {
            dataList.clear();
            for (Province province : provinceList) {
                dataList.add(province.getProvinceName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            titleText.setText("中国");
            currentLevel = LEVEL_PROVINCE;
        } else {
            queryFromServer(null, "province");
        }
    }

    /**
     * 查询选中省内所有的市，优先从数据库查询，如果没有查询到再去服务器上查询。
     */
    private void queryCities() {
        cityList = coolWeatherDB.loadCities(selectedProvince.getId());
        if (cityList.size() > 0) {
            dataList.clear();
            for (City city : cityList) {
                dataList.add(city.getCityName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            titleText.setText(selectedProvince.getProvinceName());
            currentLevel = LEVEL_CITY;
        } else {
            queryFromServer(selectedProvince.getProvinceCode(), "city");
        }
    }

    /**
     * 查询选中市内所有的县，优先从数据库查询，如果没有查询到再去服务器上查询。
     */
    private void queryCounties() {
        countyList = coolWeatherDB.loadCounties(selectedCity.getId());
        if (countyList.size() > 0) {
            dataList.clear();
            for (County county : countyList) {
                dataList.add(county.getCountyName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            titleText.setText(selectedCity.getCityName());
            currentLevel = LEVEL_COUNTY;
        } else {
            queryFromServer(selectedCity.getCityCode(), "county");
        }
    }

    /**
     * 根据传入的代号和类型从服务器上查询省市县数据。 

     */
    private void queryFromServer(final String code, final String type) {
        String address;
        if (!TextUtils.isEmpty(code)) {
            address = "http://www.weather.com.cn/data/list3/city" + code
                    + ".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
                    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();
                            }
                        }
                    });
                }

            }

            @Override
            public void onError(Exception e) {
                // 通过runOnUiThread()方法回到主线程处理逻辑
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        closeProgressDialog();
                        Toast.makeText(ChooseAreaActivity.this, "加载失败",
                                Toast.LENGTH_SHORT).show();
                    }
                });
            }
        });
    }

    /**
     * 显示进度对话框
     */
    private void showProgressDialog() {
        if (progressDialog == null) {
            progressDialog = new ProgressDialog(this);
            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();
        }
    }

    /**
     * 捕获Back按键，根据当前的级别来判断，此时应该返回市列表、省列表、还是直接退出。     */
    @Override
    public void onBackPressed() {
        if (currentLevel == LEVEL_COUNTY) {
            queryCities();
        } else if (currentLevel == LEVEL_CITY) {
            queryProvinces();
        } else {
            if (isFromWeatherActivity) {
                Intent intent = new Intent(this, WeatherActivity.class);
                startActivity(intent);
                }
            finish();
        }
    }
}