Multiple and Repetitive AsyncTask in Android

问题:

I have two asynctask working with each other. I'm using them for creating Restaurant menu. First web service gets menu's titles from database. Second web service gets items of title from database. I get title data in my first asynctask and item data in my second asynctask.

For example, I have ten menu titles. There are eight items for each title. I execute first asynctask and get all of menu titles. I want to call second asynctask in first asynctask's onPostExecute for get this title's item and add TextView. I have to wait finished every second task for add item respectively.

In short, I need call first AsyncTask and wait finish it. Then send request to second AsyncTask in First AsyncTask. I have to wait every request to finish. How can I wait ?

Here is the my code.

First AsyncTask

public class BaslikDoldurAS extends AsyncTask<String,String[][],String[][]>{
        int ParamID;

        public BaslikDoldurAS(String ParamID){
            this.ParamID=Integer.parseInt(ParamID);
        }

        @Override
        protected String[][] doInBackground(String... params) {
            BaslikDoldur(ParamID);
            return sonuc;
        }

        protected void onPostExecute(String[][] sonuc){
            for(int i=0;i<baslikCount;i++){ 
                 MenuDoldurAS kontrol = new MenuDoldurAS(firma_id,sonuc[2][i]);
                 kontrol.execute();
            } 
        }
    }

my function which is used in first asyncTask

private String[][] BaslikDoldur(Integer ParamID){
        PropertyInfo id = new PropertyInfo();
        id.name= "id";
        id.setValue(ParamID);
        id.type = PropertyInfo.INTEGER_CLASS;

        SoapObject request = new SoapObject(NAMESPACE, "BaslikDoldur");
        request.addProperty(id);
        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
        envelope.bodyOut=request;
        envelope.dotNet = true;     
        envelope.setOutputSoapObject(request);

        HttpTransportSE androidHttpTransport = new HttpTransportSE(MenuURL);
        androidHttpTransport.debug = true;

        try {

            androidHttpTransport.call("http://tempuri.org/BaslikDoldur", envelope);
            SoapObject response = (SoapObject) envelope.getResponse();

            sonuc[2]=new String[response.getPropertyCount()]; //baslik
            baslikCount=response.getPropertyCount();

            for(int i=0;i<response.getPropertyCount();i++){    
                   Object property = response.getProperty(i);
                   if(property instanceof SoapObject){
                       SoapObject menu = (SoapObject) property;
                       sonuc[2][i] = menu.getProperty("menu_baslik").toString();
                   }
            }
     } 
             catch (Exception e) {          
                e.printStackTrace();
            }
        return sonuc;

    }

Second AsyncTask

public class MenuDoldurAS extends AsyncTask<String,String[][],String[][]>{
        int ParamID;
        String Baslik;

        public MenuDoldurAS(String ParamID,String Baslik){
            this.ParamID=Integer.parseInt(ParamID);
            this.Baslik=Baslik;
        }
        @Override
        protected String[][] doInBackground(String... params) {
            MenuDoldur(ParamID,Baslik);
            return sonuc;
        }

        protected void onPostExecute(String[][] sonuc){
            for(int i=0;i<count;i++){
                String baslik="";
                if(!baslik.equals(sonuc[2][i])){
                    baslik=sonuc[2][i];
                    TextView basliktxt = new TextView(Urun.this);
                    basliktxt.setText(sonuc[2][i]);
                    basliktxt.setTextSize(20);
                    basliktxt.setTextColor(Color.RED);
                    basliktxt.setGravity(Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL);
                    urunLayout.addView(basliktxt);
                }
                else{
                    TextView aciklamatxt = new TextView(Urun.this);
                    aciklamatxt.setText(sonuc[3][i]);
                    aciklamatxt.setTextColor(Color.parseColor("#0c0c7c"));
                    aciklamatxt.setTextSize(17);
                    aciklamatxt.setGravity(Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL);
                    urunLayout.addView(aciklamatxt);
                }
            }   
        }

    }

my function which is used in second asyncTask

private String[][] MenuDoldur(Integer ParamID,String Baslik){
        PropertyInfo id = new PropertyInfo();
        id.name= "id";
        id.setValue(ParamID);
        id.type = PropertyInfo.INTEGER_CLASS;

        PropertyInfo baslik = new PropertyInfo();
        baslik.name= "baslik";
        baslik.setValue(Baslik);
        baslik.type = PropertyInfo.STRING_CLASS;

        SoapObject request = new SoapObject(NAMESPACE, "MenuDoldur");
        request.addProperty(id);
        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
        envelope.bodyOut=request;
        envelope.dotNet = true;     
        envelope.setOutputSoapObject(request);

        HttpTransportSE androidHttpTransport = new HttpTransportSE(MenuURL);
        androidHttpTransport.debug = true;

        try {

            androidHttpTransport.call("http://tempuri.org/MenuDoldur", envelope);
            SoapObject response = (SoapObject) envelope.getResponse();

            sonuc[3]=new String[response.getPropertyCount()]; //aciklama ve fiyat
            count = response.getPropertyCount();

            for(int i=0;i<response.getPropertyCount();i++){    
                   Object property = response.getProperty(i);
                   if(property instanceof SoapObject){
                       SoapObject menu = (SoapObject) property;
                       sonuc[3][i] = menu.getProperty("menu_aciklama").toString() + " - " + menu.getProperty("menu_fiyat").toString();
                   }
            }
     } 
             catch (Exception e) {          
                e.printStackTrace();
            }
        return sonuc;   

    }

回答1:

If you want to wait until all AsyncTasks are done before proceeding, why don't you just put all of you work in doInBackground of the first AsyncTask?

Or you don't want to do this because you want to run the 10 "second tasks" in parallel? (Which, incidentally you're not doing anyway, because you're not using the THREAD_POOL Executor for your tasks.) If this is the case then why not just do something like

// variable accessible to both tasks
ArrayList<AsyncTask> mRunningTasks = new ArrayList<AsyncTask>();
// AsyncTask1
protected void onPostExecute(String[][] sonuc){
    for(int i=0;i<baslikCount;i++){ 
         MenuDoldurAS kontrol = new MenuDoldurAS(firma_id,sonuc[2][i]);
         mRunningTasks.add(kontrol);
    }
    for (AsyncTask task : mRunningTasks) {
        task.execute();
    }
}

// AsyncTask2
protected void onPostExecute(...) {
    boolean allComplete = true;
    for (AsyncTask task : mRunningTasks) {
      if (!task.getStatus().equals(AsyncTask.Status.FINISHED)) {
          allComplete = false;
          break;
      }
    }
    if (allComplete) {
       //do whatever
       mRunningTasks.clear();
    }
}