Question

如何在特定点终止功能我使用break但它不起作用请帮助我当我想要当前日期与数据库没有进一步处理并且函数关闭中断时不能正常工作其他建议?????

                public class getDataTask extends AsyncTask<Void, Void, Void> {

    getDataTask() {

    }

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
         yourBoolean=false;
    }

    @Override
    protected Void doInBackground(Void... arg0) {
        // TODO Auto-generated method stub

        displayData();
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        yourBoolean=true ;
        listCategory.setAdapter(cla);
        menu_nametxt.setText(mVal2);
                                  }








                    private void displayData() {


    Cursor mCursor2 =  db.selectQuery("SELECT s.name ASxxxx ORDER BY md.sort ASC");


    if (mCursor2.moveToFirst()) {
        do {



        Calendar_id =(mCursor2.getString(mCursor2.getColumnIndex("calendar_id")));


        } while (mCursor2.moveToNext());
    }


    mCursor2.close();






 Cursor mCursor3 =  db.selectQuery("SELECT * FROM uss_vacation WHERE calendar_id = 
      '"+Calendar_id+"' ");


    if (mCursor3.moveToFirst()) {
        do {


  Vacation_Date.add(mCursor3.getString(mCursor3.getColumnIndex("date")));

    if(mCursor3.getString(mCursor3.getColumnIndex("date")).equals(mydate))
            {
           String  mVal  ;
                mVal = 
  (mCursor3.getString(mCursor3.getColumnIndex("title")));

        //
                mVal3 = mVal;

  //////////////////////////////help here//////////////////////
 i want function displayData(); close at this like and not processing further any idea?? i used 
    break but is not work
                break;

            }


        } while (mCursor3.moveToNext());
    }


    mCursor3.close();








Cursor mCursor =  db.selectQuery("SELECT s.name  '"+Meal_groupid+"' ORDER BY md.sort ASC");
    Category_ID.clear();
    school_name.clear();
    menu_name.clear();

    dish_name.clear();
    dish_ID.clear();
    day.clear();



    if (mCursor.moveToFirst()) {
        do {

            zero1check = valll.toString();
            if (zero1check.equals("0"))
                byweekdate = Todayday + 1;
            else if (zero1check.equals("1")) {
                byweekdate = Todayday + 2;

            }

      school_name.add(mCursor.getString(mCursor.getColumnIndex("school_name")));
            String Scdedulechk;

            Scdedulechk=(mCursor.getString(mCursor.getColumnIndex("Schedule")));
            Schedule.add(mCursor.getString(mCursor.getColumnIndex("Schedule")));
            day.add(mCursor.getString(mCursor.getColumnIndex("day")));

            String chkdate;

            chkdate=(mCursor.getString(mCursor.getColumnIndex("day")));


            if ((Scdedulechk).equals("weekly")) {

                if ((chkdate).equals(Todayday)) {




       menu_name.add(mCursor.getString(mCursor.getColumnIndex("menu_title")));
            String menu_title;

            menu_title=
      (mCursor.getString(mCursor.getColumnIndex("menu_title")));
            mVal2=menu_title.toString();


   dish_name.add(mCursor.getString(mCursor.getColumnIndex("dish_name")));

dish_ID.add(mCursor.getString(mCursor.getColumnIndex("dish_id")));



   Category_ID.add(mCursor.getString(mCursor.getColumnIndex("calendar_id")));
                }
            }
            else 
                if ((Scdedulechk).equals("biweekly")) {

                    if ((chkdate).equals(byweekdate)) {




   menu_name.add(mCursor.getString(mCursor.getColumnIndex("menu_title")));


   dish_name.add(mCursor.getString(mCursor.getColumnIndex("dish_name")));


     dish_ID.add(mCursor.getString(mCursor.getColumnIndex("dish_id")));



    Category_ID.add(mCursor.getString(mCursor.getColumnIndex("calendar_id")));
                    }
                }


        } while (mCursor.moveToNext());
    }


    mCursor.close();


}

Answer 1

将break替换为return。 break只是打破循环，return“停止”该方法。

Answer 2

将函数的返回类型从void更改为int或else，并在完成所需操作后返回任何内容。例如。

int test_func(){ 

 //your code here
if(actionCompleted){
    return 1;
// function will be closed 
 }
else
//your code

return 0;
}

android如何终止函数并在获取特定值后返回异步任务

2 个答案: