我在我的活动中调用一个函数,这基本上是一个异步任务,通过webservice从远程服务器获取数据。如何取消异步任务
private void myAsyncTask() {
new AsyncTask<Object, Object, Object>() {
@Override
protected void onPreExecute() {
progress_Dialog = ProgressDialog.show(a, "", "Loading");
}
@Override
protected Integer doInBackground(Object... params) {
try
{
try {
MenuService menuService = new MenuServiceImpl();
MenuServiceResponse partnerMenu;
partnerMenu = menuService.getMenu();
productlist=Menu.getMenu().getMenuEntries();
System.gc();
return 0;
} catch (myServiceException e) {
bgFlag=true;
e.printStackTrace();
}
}
catch (Exception e) {
bgFlagForserviceExeption=true;
e.printStackTrace();
}
} return 0;
}
@Override
protected void onPostExecute(Object result) {
if (progress_Dialog != null) {
progress_Dialog.dismiss();
}
try
{
if(bgFlagForserviceExeption)
{
MyAlertDialog.ShowAlertDialog(ShopActivity.this, "", "Please try again later", "OK");
}
if(bgFlag==false)
{
adapter = new ShopAdapter(
ShopActivity.this, productlist);
allproduts.setAdapter(adapter);
}
else
{
MyAlertDialog.ShowAlertDialog(ShopActivity.this, "", " Please try again later", "OK");
}
}
catch(Exception e)
{
adapter=null;
}
}
}.execute();
}
当我把这个活动的进度条会显示,直到doinbackground()ends.How我可以从手机按后退按钮后台进程退出,现在的问题是,我将不得不等待,直到即使我按下后退按钮,后台进程也会完成。如何才能达到此效果
你不能用'doInBackground'做到这一点是这样的...'AsyncTask.cancel'只能帮助,那么你在'doInBackground'循环,在你每一次迭代做的事情检查isCancelled(),然后打破循环... – Selvin
更多的explenation(关于为什么'AsyncTask.cancel'不适用于此)...实际上有一个很大的机会,你的代码“卡住”在' getMenu()'或'getMenuEntries()'方法和'doInBackground'你没有可能停止他们的... – Selvin
http://stackoverflow.com/questions/6356956/onbackpressed-doesnt-trigger-when-showing-progressdialog – Selvin