上一篇
我們已經把數據庫構建好,同時創建了Utility類,明確了數據庫的操作
界面設計
這裏我只做簡單的介紹,把整個設計的理念講述一下:
我們創建一個ChooseAreaFragment,它的主要作用爲:App一開始時顯示這個界面,默認顯示省份的信息。在這個界面中我們可以進行省,市,縣的選擇。當選擇了縣之後,我們就跳轉到了WeatherActivity。此時,我們的ChooseAreaFragment作爲WeatherActivity的滑動菜單欄。所以我們一定要在ChooseAreaFragment中對此時Fragment所在位置進行判斷:
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.refrshLayout.setRefreshing(true);
activity.requestWeather(weatherId);
}
我們要注意:
在Okhttp的回調函數中,我們不能進行UI操作,Android的UI操作必須要在主線程中進行,所以我們使用了runOnUiThread執行UI操作。
在Fragment中,我們在onActivityCreated中執行監聽事件的操作。
在ChooseAreaFragment的操作基本流程是:
我們定義了currentLevel用於判斷當前的省,市,縣級別,根據級別來進行界面的顯示。打開App時,默認狀態下顯示的是全國省份的信息,一開始我們需要判斷數據庫中是否存在省份信息,如果不存在就去服務器上尋找。當然,最初是向服務器獲取數據存儲到數據庫中的。這裏我只貼了查詢省份的代碼:
private void queryProvinces() {
title.setText("中國");
btn_back.setVisibility(View.GONE);//不顯示返回按鈕
provinceList = DataSupport.findAll(Province.class);//查找數據庫中所有的內容
if (provinceList.size() > 0) {
dataList.clear();//清除列表中內容
for (Province province : provinceList) {
dataList.add(province.getProvinceName());
}
adapter.notifyDataSetChanged();
listView.setSelection(0);
currentLevel = LEVEL_PROVINCE;
} else {
String address = ADDRESS;
queryFromServer(address, "province");//從服務器中尋找數據
}
}
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) {
// 通過runOnUiThread()方法回到主線程處理邏輯
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
closeProgressDialog();
makeText(getContext(), "加載失敗", LENGTH_SHORT).show();
}
});
}
});
}
注意:在WeatherActivity中獲取天氣信息的地址爲:
String weatherUrl = "https://api.heweather.com/x3/weather?cityid=" + weatherId + "&key=bc0418b57b2d4918819d3974ac1285d9";
public void requestWeather(final String weatherId) {
String weatherUrl = "https://api.heweather.com/x3/weather?cityid=" + weatherId + "&key=bc0418b57b2d4918819d3974ac1285d9";
HttpUtil.sendOkHttpRequest(weatherUrl, new Callback() {
@Override
public void onResponse(Call call, Response response) throws IOException {
final String responseText = response.body().string();
final Weather weather = Utility.handleWeatherResponse(responseText);
runOnUiThread(new Runnable() {
@Override
public void run() {
if (weather != null && "ok".equals(weather.status)) {
SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(WeatherActivity.this).edit();
editor.putString("weather", responseText);
editor.apply();
showWeatherInfo(weather);
} else {
Toast.makeText(WeatherActivity.this, "獲取天氣信息失敗", Toast.LENGTH_SHORT).show();
}
refrshLayout.setRefreshing(false);
}
});
}
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(WeatherActivity.this, "獲取天氣信息失敗", Toast.LENGTH_SHORT).show();
refrshLayout.setRefreshing(false);
}
});
}
});
}
下載更新背景圖:
private void loadPic() {
String address = "http://guolin.tech/api/bing_pic";
HttpUtil.sendOkHttpRequest(address, new Callback() {
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
}
@Override
public void onResponse(Call call, Response response) throws IOException {
final String pic = response.body().string();
SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(WeatherActivity.this).edit();
editor.putString("pic", pic);
editor.apply();
runOnUiThread(new Runnable() {
@Override
public void run() {
Glide.with(WeatherActivity.this).load(pic).into(back_img);
}
});
}
});
}
我們在佈局中使用了SwipeRefreshLayout,這樣我們可以手動更新數據:
//設置監聽事件
refrshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
requestWeather(weatherId);
loadPic();
}
});
注意:在使用DrawerLayout佈局實現側滑菜單欄效果是,我們要給作爲菜單欄的佈局設置背景色,這樣就不會導致側滑菜單欄出現的時候,被黑色的陰影蓋住,看不見菜單欄。