coolweather3

学习目的：1.布局+数据库 显示市级界面 县级界面 省级界面

新建choose_area.xml

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

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary">

        <TextView
            android:id="@+id/title_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:textColor="#fff"
            android:textSize="20sp"/>

        <Button
            android:id="@+id/back_button"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:layout_marginLeft="10dp"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:background="@drawable/ic_back"/>
    </RelativeLayout>

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</LinearLayout>

关键：编写用于遍历省市县数据的碎片 新建Choose-AreaFragment类继承Fragment

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.coolweather.android.db.City;
import com.coolweather.android.db.County;
import com.coolweather.android.db.Province;
import com.coolweather.android.util.HttpUtil;
import com.coolweather.android.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 {

    private static final String TAG = "ChooseAreaFragment";

    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，优先从数据库查询，如果没有查询到再去服务器上查询。
     */
    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，优先从数据库查询，如果没有查询到再去服务器上查询。
     */
    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，优先从数据库查询，如果没有查询到再去服务器上查询。
     */
    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 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();
                            }
                        }
                    });
                }
            }

            @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();
                    }
                });
            }
        });
    }

    /**
     * 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();
        }
    }

}

遍历省市县数据完成 但碎片不能直接显示在界面上 还需添加到活动里activity_main.xml

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

    <fragment
        android:id="@+id/choose_area_fragment"
        android:name="com.coolweather.android.ChooseAreaFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

另外 由于碎片布局已定义标题栏 所以不需要ActionBar 所以修改style.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

</resources>

申请权限

<uses-permission android:name="android.permission.INTERNET" />

到此可以显示市级界面 县级界面 省级界面 ！