Question

我正在尝试获取当前季度的第一个和最后一个日期，我正在使用它：

NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitQuarter | NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];

components.quarter = 1;

funStartDate = [[NSCalendar currentCalendar] dateFromComponents: components];
NSLog(@"First day of quater: %@", funStartDate);

[components setQuarter:[components quarter]+1];

funEndDate = [[NSCalendar currentCalendar] dateFromComponents: components];
NSLog(@"Last day of quater: %@", [funEndDate descriptionWithLocale:[NSLocale currentLocale]]);

但在两个控制台打印中，我看到了今天的日期。我做错了什么？

Answer 1

更新：我发现苹果公司的季度单位错误仍然存在于iOS 7.1中，因此请避免在日期组件中使用此单元。

我在这里为您找到了解决方案：

一季度的第一天：

    NSDate *date = <whatever>;
    NSCalendar *currentCalendar = [NSCalendar currentCalendar];
    NSDate *startOfQuarter;
    [currentCalendar rangeOfUnit: NSQuarterCalendarUnit
                       startDate: &startOfQuarter
                        interval: NULL
                         forDate: date];
    NSLog(@"quarter starts at %@", startOfQuarter);

一季度的最后一天：

    NSDateComponents* comps = [currentCalendar components:(NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay)
                                                 fromDate:date];
    NSUInteger quartalNum = (comps.month - 1) / 3 + 1;
    NSUInteger lastQuartalMonthNum = quartalNum * 3;
    NSUInteger nextQuartalFirstMonth = lastQuartalMonthNum + 1
    [comps setMonth: nextQuartalFirstMonth];
    [comps setDay: 0]; // with 0 day we get last day of previous month

    NSLog(@"quarter ends at %@",  [currentCalendar dateFromComponents: comps]);

Answer 2

Swift 3.1。四分之一部分仍无效。解决方法：

Date().startOfQuarter

用法：

#include <stdio.h>
#include <stdlib.h>

unsigned char I2C_Read()
{
    unsigned char b = 0b11111111;
    return b;
}

void GetTime(unsigned char *a)
{
    *a = I2C_Read();
}

int main()
{
    unsigned char *a = 0;   
    GetTime(a);                        // ?

    printf("Value of b is: %d\n" , b); // ?
}

获得本季度的第一个日期

2 个答案: