如何从objective-c中的另一个类的函数中获取返回值？

Question

这是来自Tapku的方法，我想从控制器中调用它

- (NSDate*) dateSelected{
if(selectedDay < 1 || selectedPortion != 1) return nil;

TKDateInformation info = [monthDate dateInformationWithTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
info.hour = 0;
info.minute = 0;
info.second = 0;
info.day = selectedDay;
NSDate *d = [NSDate dateFromDateInformation:info timeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];


return d;

}

我试图像这样调用它并将其转换为字符串格式。

TKCalendarMonthView *tk=[[TKCalendarMonthView alloc] init];
NSDate *date=tk.dateSelected;// How can I call it?With the debug it shows it's null.
NSDateFormatter *selectedDate=[[NSDateFormatter alloc] init];
[selectedDate setDateFormat:@"yyyy-MM-dd"];
NSMutableString *stringDate=[NSMutableString stringWithFormat:@"%@",[selectedDate stringFromDate: date]]`

Answer 1

NSDate *date= [tk dateSelected];

使其成为函数调用（严格来说，向对象发送消息）。点语法仅适用于getter / setter。我强烈建议先阅读objc basic。