ios - 完成 block 完成后返回一个数组

Question

我有以下功能

- (NSArray*) calendarMonthView:(TKCalendarMonthView*)monthView marksFromDate:(NSDate*)startDate toDate:(NSDate*)lastDate{
    AppDelegate* appDelegate = [UIApplication sharedApplication].delegate;
    _currentStart = startDate;
    _currentEnd = lastDate;
    
    if(appDelegate.internetActive){
        Webservice *web = [[Webservice alloc]init];
        [web fetchAppointmentsOnCompletionFor:startDate andEnd:lastDate OnCompletion:^(BOOL finished) {
            if(finished){
                [self generateRandomDataForStartDate:startDate endDate:lastDate];
                 // NOW return the self.dataArray
            }
        }];
    }
    return self.dataArray; 
}

我不知道如何在 completionblock 完成时返回 self.dataArray。因为我的 self.dataArray 是在 generateRandomDataForStartDate:startDate 方法中填充的。所以目前函数总是返回一个空数组。

Answer 1

您应该在参数中传递完成处理程序 block 。将返回类型设置为 void。

调用者对象将编写以下代码:

[calenderView calendarMonthView:monthView marksFromDate:startDate toDate:lastDate completionHandler:^(NSarray *dataArray){
//Process data array over here
}];

- (void) calendarMonthView:(TKCalendarMonthView*)monthView marksFromDate:(NSDate*)startDate toDate:(NSDate*)lastDate completionHandler:(void (^)(NSArray*))completionBlock{
    AppDelegate* appDelegate = [UIApplication sharedApplication].delegate;
    _currentStart = startDate;
    _currentEnd = lastDate;

    if(appDelegate.internetActive){
        Webservice *web = [[Webservice alloc]init];
        [web fetchAppointmentsOnCompletionFor:startDate andEnd:lastDate OnCompletion:^(BOOL finished) {
            if(finished){
                [self generateRandomDataForStartDate:startDate endDate:lastDate];
                 completionBlock(self.dataArray);
            }
        }];
    }
    completionBlock(self.dataArray);
}

在调用者代码句柄完成 block 中，响应数组作为 argumnet 接收。