iOS之獲取定月的第一天和最後一天

iOS獲取定月的第一天和最後一天

+ (NSString *)getMonthBeginAndEndWith:(NSString *)dateStr{  
      
    NSDateFormatter *format=[[NSDateFormatter alloc] init];  
    [format setDateFormat:@"yyyy-MM"];  
    NSDate *newDate=[format dateFromString:dateStr];  
    double interval = 0;  
    NSDate *beginDate = nil;  
    NSDate *endDate = nil;  
    NSCalendar *calendar = [NSCalendar currentCalendar];  
      
    [calendar setFirstWeekday:2];//設定週一爲周首日  
    BOOL ok = [calendar rangeOfUnit:NSMonthCalendarUnit startDate:&beginDate interval:&interval forDate:newDate];  
    //分別修改爲 NSDayCalendarUnit NSWeekCalendarUnit NSYearCalendarUnit  
    if (ok) {  
        endDate = [beginDate dateByAddingTimeInterval:interval-1];  
    }else {  
        return @"";  
    }  
    NSDateFormatter *myDateFormatter = [[NSDateFormatter alloc] init];  
    [myDateFormatter setDateFormat:@"YYYY.MM.dd"];  
    NSString *beginString = [myDateFormatter stringFromDate:beginDate];  
    NSString *endString = [myDateFormatter stringFromDate:endDate];  
    NSString *s = [NSString stringWithFormat:@"%@-%@",beginString,endString];  
    return s;  
}  

方法的調用

   ///調用格式（yyyy-MM）
    NSString *dateStr = [self getMonthBeginAndEndWith:@"2016-9"];