西瓜是肥貓

基本上下cancel 之後 他會做完pre back post 目前的區塊，然後不往下個區塊去做。

但在建構式下 cancel 依然會執行pre 的區塊。

Example code 

public class AsynTaskCancelExample{

public enum STOP{

CON,PRE,BACK,POST

}

public void start(){

new ExAsynTaskCencel(STOP.CON).execute();

new ExAsynTaskCencel(STOP.PRE).execute();

new ExAsynTaskCencel(STOP.BACK).execute();

new ExAsynTaskCencel(STOP.POST).execute();

}

private class ExAsynTaskCencel extends AsyncTask<Void,Void,Boolean>{

STOP so;

public ExAsynTaskCencel(STOPs){

so = s;

if(so==STOP.CON)cancel(true);

Log.d("DEYU"+so,"cancel");

}

@Override

protected void onPreExecute(){

super.onPreExecute();

if(so==STOP.PRE)cancel(true);

Log.d("DEYU"+so,"onPreExecute");

}

@Override

protected BooleandoInBackground(Void...params){

if(so==STOP.BACK)cancel(true);

Log.d("DEYU"+so,"doInBackground");

return null;

}

@Override

protected void onPostExecute(Booleanresult){

super.onPostExecute(result);

if(so==STOP.POST)cancel(true);

Log.d("DEYU"+so,"onPostExecute");

}

}

}

output Log : 

12-11 11:37:55.736: D/DEYUCON(29846): cancel

12-11 11:37:55.736: D/DEYUCON(29846): onPreExecute

12-11 11:37:55.736: D/DEYUPRE(29846): cancel

12-11 11:37:55.737: D/DEYUPRE(29846): onPreExecute

12-11 11:37:55.737: D/DEYUBACK(29846): cancel

12-11 11:37:55.737: D/DEYUBACK(29846): onPreExecute

12-11 11:37:55.737: D/DEYUBACK(29846): doInBackground

12-11 11:37:55.737: D/DEYUPOST(29846): cancel

12-11 11:37:55.737: D/DEYUPOST(29846): onPreExecute

12-11 11:37:55.737: D/DEYUPOST(29846): doInBackground

12-11 11:37:55.741: D/DEYUPOST(29846): onPostExecute