进入实战，开发酷欧天气（四）

流过泪的眼睛更明亮，滴过血的心灵更坚强！ 

本讲内容：显示天气信息

服务器返回的天气数据来决定布局

{"weatherinfo":{"city":"昆山","cityid":"101190404","temp1":"20℃","temp2":"11℃","weather":"小雨","img1":"d7.gif","img2":"n7.gif","ptime":"08:00"}}

这里我们选择显示在界面有城市名、温度范围、天气信息描述、发布时间这几项，接下来就合理安排这几项数据的显示位置。

下面是res/layout/weather_layout.xml布局

<?xml version="1.0" encoding="utf-8"?>
<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>

下面是 WeatherActivity.java文件

public class WeatherActivity extends Activity implements OnClickListener{

	private LinearLayout weatherInfoLayout;
	/**
	 * 用于显示城市名
	 */
	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;
	
	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);
	}
	
	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;
		}
	}
	
	/**
	 * 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() {
			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() {
						public void run() {
							showWeather();
						}
					});
				}
			}
			
			public void onError(Exception e) {
				runOnUiThread(new Runnable() {
					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);
	}

}

如何从ChooseAreaActivity跳转到WeatherActivity了，修改下 ChooseAreaActivity中的代码

public class ChooseAreaActivity extends BaseActivity {
……
		
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
		if (prefs.getBoolean("city_selected", false)) {
			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() {
			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
	}
……	
	}

修改了两处，在onCreate()方法的一开始先从SharedPreferences文件中读取city_selected标志位，如果为true就说明当前已经选择城市了，第二判断……

然后注册下新增活动。

2、切换城市和手动更新天气按钮

在ChooseAreaActivity对isFromWeatherActivity标志位进行处理

public class ChooseAreaActivity extends BaseActivity {

	……
	/**
	 * 是否从WeatherActivity中跳转过来。
	 */
	private boolean isFromWeatherActivity;
	
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		isFromWeatherActivity = getIntent().getBooleanExtra("from_weather_activity", false);
		SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
		//已经选择了城市且不是从WeatherActivity跳转过来，才会直接跳转到WeatherActivity
		if (prefs.getBoolean("city_selected", false) && !isFromWeatherActivity) {
			Intent intent = new Intent(this, WeatherActivity.class);
			startActivity(intent);
			finish();
			return;
		}
		……
	
	/**
	 * 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。
	 */
	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();
		}
	}

}

第三阶段开发 工作完成了，我们把代码提交一下。

git add .

git commit -m "加入显示天气信息的功能。"

git push origin master