我有一个类 GetWeather.java，它从 API 获取天气数据。它通过一个单独的线程定期从我的应用程序的主要活动中调用。线程点击 GetWeather 类并将返回的数据发布到 TextView。
在任何一种情况下，从 GetWeather 类中返回的数据的 System.out.println 都表明确实正在返回数据。
下面是GetWeather.java：
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.net.Uri;
import android.util.Log;
public class GetWeather {
InputStream is = null;
JSONArray jArray = null;
JSONObject json_data = new JSONObject();
String result = "";
String strTemp = "";
String strWindSpeed = "";
String strWindDir = "";
String strVisibility = "";
String strPosition = "";
public static final Uri KEY_121 = Uri.parse("http://api.worldweatheronline.com/free/v1/weather.ashx");
String strWeatherApiKey = "REMOVED";
public GetWeather(String Location) {
strPosition = Location;
}
public void returnWeather() {
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(KEY_121 + "?key="
+ strWeatherApiKey + "&q=" + strPosition + "&format=json");
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
// convert response to string
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
// parse json data
try {
JSONObject object = new JSONObject(result);
JSONObject weather = object.getJSONObject("data");
JSONArray current_conditions = weather
.getJSONArray("current_condition");
for (int i = 0; i < current_conditions.length(); i++) {
JSONObject object1 = (JSONObject) current_conditions.get(i);
strTemp = object1.getString("temp_C");
strWindSpeed = object1.getString("windspeedMiles");
strWindDir = object1.getString("winddir16Point");
strVisibility = object1.getString("visibility");
// Testing output
System.out.println(strTemp);
System.out.println(strWindSpeed);
System.out.println(strWindDir);
System.out.println(strVisibility);
}
} catch (JSONException e) {
Log.e("log_tag", "Error parsing data " + e.toString());
}
}
}
以下是主要活动的相关代码：
Runnable updateConsoleRunnable = new Runnable() {
public void run() {
tvConsole.setMovementMethod(new ScrollingMovementMethod());
tvConsole.setSelected(true);
handler.postDelayed(this, TIME_DELAY);
// Only display weather data while service is enabled
if (isServiceRunning()) {
GetWeather weather = new GetWeather(strPosition);
weather.returnWeather();
// Weather package
tvConsole
.append("Weather Update\n-------------------\n\nCurrent Temp (C): "
+ weather.strTemp
+ "C\n"
+ "Wind is out of the "
+ weather.strWindDir
+ " at "
+ weather.strWindSpeed
+ " MPH\n"
+ "Visibility is "
+ weather.strVisibility
+ " miles\n\n");
// Auto-scroll textview
// Does not function on Android 4.0+
final Layout layout = tvConsole.getLayout();
if (layout != null) {
int scrollDelta = layout.getLineBottom(tvConsole
.getLineCount() - 1)
- tvConsole.getScrollY()
- tvConsole.getHeight();
if (scrollDelta > 0)
tvConsole.scrollBy(0, scrollDelta);
}
}
}
};
正如我之前提到的，这在 Gingerbread 和 中按预期工作，FroYo但是操作系统无法看到 GetWeather 设置的变量。我想，我在某处读到这与需要 AsyncTask 有关，但我无法确定它的正面或反面。ICSJellyBean
提前谢谢