onPostExecute在task.execute（）

Question

我遇到了AsyncTask的问题

String latlong = "lat=48.8534100&lon=2.3488000";
city = "Paris";
getWeather w = new getWeather(latlong,this);
w.execute();

这个gs.alerter（）应该在onpostexecute之后执行，但它是在之前执行的

gs.alerter("thiss" + currentWeather); //This is a Log.i function
gs.cities.add(new City(city, currentWeather + "°", image));
initializeAdapter();

AsyncTask类是：

public class getWeather extends AsyncTask<Void, Void, JSONObject> {

String latlong;
MainActivity obj;
JSONParser jParser = new JSONParser();
JSONObject json;

public getWeather(String latlong,MainActivity obj)
{
    this.latlong = latlong;
    this.obj = obj;
}

@Override
protected JSONObject doInBackground(Void... params) {
    // TODO Auto-generated method stub
    String URL = "http://api.openweathermap.org/data/2.5/weather?" +
            latlong +
            "&appid=APIKEY" +
            "&units=metric";
    json = jParser.getJSONFromUrl(URL);
    return json;
}

@Override
protected void onPostExecute(JSONObject result) {
    this.obj.setWeather(result);
}

@Override
protected void onPreExecute() {
    super.onPreExecute();
}

}

setweather代码在活动类上：

public void setWeather(JSONObject obj){
    try {
        JSONObject main = obj.getJSONObject("main");
        Double initWeather = new Double(main.getString("temp"));
        int finalWeather = (int)Math.round(initWeather * 1) / 1;
        this.currentWeather = Integer.toString(finalWeather);

此gs.alerter（）应该在.execute（）

之后立即执行

        gs.alerter(this.currentWeather);
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

所以问题是在onpostexecute（）之后执行.execute（）之后的代码。我想按此顺序执行它： 。执行（） onpostexecute（）来影响currentWeather变量 然后添加City ...

需要任何帮助。

谢谢大家

PS：我是Android开发的初学者：）

Answer 1

1. 创建界面

  

public interface OnTaskCompleted {           void onTaskCompleted（）;       }

1. 您的活动代码将如下所示

   class YourActivity implements OnTaskCompleted {
   void someFunctionToExecute()
   {
     String latlong = "lat=48.8534100&lon=2.3488000";
     city = "Paris";
     getWeather w = new getWeather(latlong,this);
     w.execute();
   }
   // this code will be called after postExecute
    void OnTaskCompleted(){
       gs.alerter("thiss" + currentWeather); 
       gs.cities.add(new City(city, currentWeather + "°", image));
       initializeAdapter();
    }
   

   }

2. 您的AsyncTask代码看起来像

public class getWeather extends AsyncTask<Void, Void, JSONObject> {
String latlong;
MainActivity obj;
JSONParser jParser = new JSONParser();
JSONObject json;

public getWeather(String latlong,MainActivity obj)
{
    this.latlong = latlong;
    this.obj = obj;
}

@Override
protected JSONObject doInBackground(Void... params) {
    // TODO Auto-generated method stub
    String URL = "http://api.openweathermap.org/data/2.5/weather?" +
            latlong +
            "&appid=APIKEY" +
            "&units=metric";
    json = jParser.getJSONFromUrl(URL);
    return json;
}

@Override
protected void onPostExecute(JSONObject result) {
    this.obj.setWeather(result);
}

@Override
protected void onPreExecute() {
    super.onPreExecute();
    obj.OnTaskCompleted(); // calling after postexecute 
}
}

Answer 2

  

将此代码放入方法中：

public void methodName() {
    gs.alerter("thiss" + currentWeather); //This is a Log.i function
    gs.cities.add(new City(city, currentWeather + "°", image));
    initializeAdapter();
}

  

现在：

@Override
protected void onPostExecute(JSONObject result) {
    this.obj.setWeather(result);
    obj.methodName();
}