Iphone 当为eEntityTypeEvent请求AccessToEntityType时，MBProgressHUD对象不显示

我想显示MBProgressHUD对象-progressHud在进程中自动向日历添加大约100个事件。下面是我按按钮执行此任务时的代码

- (IBAction)add_event_for_test:(id)sender{
    self.progressHud = [[MBProgressHUD alloc] initWithView:self.view];
    self.progressHud.labelText = @"Adding some events to test";
    self.progressHud.detailsLabelText = @"Please wait...";
    [self.view addSubview:self.progressHud];
    [self.progressHud showWhileExecuting:@selector(add_more_event_execute:) onTarget:self withObject:nil animated:YES]; 
}

在下面的add_more_event_execute函数中，如果我试图请求访问eEntityTypeEvent的entity type以将新事件添加到iOS6中的日历中，则progressHud会立即显示和隐藏我需要显示progressHud，直到所有事件完全添加到日历。如果我不请求访问并在iOS5中运行它，progressHud工作正常

- (void) add_more_event_execute: (id)object{

    @autoreleasepool {
        eventStore=[[EKEventStore alloc] init];
        if([eventStore respondsToSelector:@selector(requestAccessToEntityType:completion:)]) {

            // iOS 6 and later
            [eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error) {

                if (granted){
                // now add 100 event to calendar
                    int i = 0;
                    while (i < 100) {
                        EKEvent *addEvent=[EKEvent eventWithEventStore:eventStore];
                        NSString *tmp1 = @"Title iOS6: ";
                        tmp1 = [tmp1 stringByAppendingString:[NSString stringWithFormat: @" %d",i]];
                        addEvent.title = tmp1;

                        NSCalendar *calendar = [NSCalendar currentCalendar];
                        NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit ) fromDate:[NSDate date]];
                        [components setMonth:0];
                        [components setDay:i - 50]; //reset the other components
                        [components setYear:0]; //reset the other components
                        NSDate *dayi = [calendar dateByAddingComponents:components toDate:[NSDate date] options:0];
                        addEvent.startDate = dayi;
                        addEvent.endDate = [addEvent.startDate dateByAddingTimeInterval:600];
                        [addEvent setCalendar:[eventStore defaultCalendarForNewEvents]];

                        NSError *err;
                        [eventStore saveEvent:addEvent span:EKSpanThisEvent error:&err];
                        if (err == nil) {
                            NSString* str = [[NSString alloc] initWithFormat:@"%@", addEvent.eventIdentifier];
                            NSLog(@"String iOS6 %d: %@ ngay:%@ ",i, str,addEvent.startDate);
                        }
                        else {
                            NSLog(@"Error %@",err);
                        }
                        i++;
                    } 
                }
                else
                {
                    //----- codes here when user NOT allow your app to access the calendar.
                }

            }];

        }
    }
}

-（void）添加更多事件执行：（id）对象{
@自动释放池{
eventStore=[[EKEventStore alloc]init]；
if（[eventStore respondsToSelector:@selector（requestAccessToEntityType:完成：）]））{
//iOS 6及更高版本
[eventStore requestAccessToEntityType:eEntityTypeEvent completion:^（已授予布尔，N错误*错误）{
如果（授予）{
//现在将100个事件添加到日历中
int i=0；
而（i<100）{
EKEvent*addEvent=[EKEvent-eventWithEventStore:eventStore]；
NSString*tmp1=@“标题iOS6:”；
tmp1=[tmp1 stringByAppendingString:[NSString stringWithFormat:@“%d”，i]]；
addEvent.title=tmp1；
NSCalendar*日历=[NSCalendar currentCalendar]；
NSDateComponents*components=[日历组件：（NSYearCalendarUnit | NSMonthCalendarUnit）fromDate:[NSDate日期]]；
[组件设置月份：0]；
[components setDay:i-50]；//重置其他组件
[components setYear:0]；//重置其他组件
NSDate*dayi=[calendar dateByAddingComponents:components toDate:[NSDate date]选项：0]；
addEvent.startDate=dayi；
addEvent.endDate=[addEvent.startDate-Date-ByAddingTimeInterval:600]；
[addEvent setCalendar:[eventStore defaultCalendarForNewEvents]]；
n错误*错误；
[eventStore saveEvent:addEvent span:EKSpanThisEvent错误：&err]；
如果（err==nil）{
NSString*str=[[NSString alloc]initWithFormat:@“%@”，addEvent.eventIdentifier]；
NSLog（@“字符串iOS6%d:%@ngay:%@”，i，str，addEvent.startDate）；
}
否则{
NSLog（@“Error%@”，err）；
}
i++；
} 
}
其他的
{
//-----当用户不允许您的应用访问日历时，请在此输入代码。
}
}];
}
}
}

---

请解释我的问题并给我一个解决方案。谢谢

[self.view将子视图带到前面：HUD]；在self.progressHud=[[MBProgressHUD alloc]initWithView:self.view]之后添加此行；请不要忘记设置委派