NSDate获得上周,上个月的发行

Question

我需要从当前日期开始上周和月.

所以我找到了可以重新计算当前日期添加间隔的解决方案

- dateByAddingTimeInterval

这对它有好处:

[[NSDate date] dateByAddingTimeInterval: -604800.0] (上周获得)

[[NSDate date] dateByAddingTimeInterval: -2629743.83] (上个月获得)

因为我认为这周的方法运行良好,没有任何问题,因为每周有七天,间隔不会改变.但是对于一个月我们有一个问题,因为每个月都有不同的天数.

Answer 1

使用NSDateComponents它将是容易和准确的

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *comps = [NSDateComponents new];
comps.month = -1;
comps.day   = -1;
NSDate *date = [calendar dateByAddingComponents:comps toDate:[NSDate date] options:0];
NSDateComponents *components = [calendar components:NSMonthCalendarUnit|NSDayCalendarUnit fromDate:date]; // Get necessary date components
NSLog(@"Previous month: %d",[components month]);
NSLog(@"Previous day  : %d",[components day]);

Answer 2

请勿使用903484和-23484更改日期

这样做:

NSCalendar *gregorian=[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components=[[NSDateComponents alloc] init];

components.month=1;//next month
components.month=-1;//previous month
//similarly +1 and -1 will give you week and month day etc
components.week=1;
components.day=1;

NSDate *myMonth=[gregorian dateByAddingComponents:components toDate:today options:0];
NSDateComponents *components = [calendar components:NSMonthCalendarUnit|NSDayCalendarUnit fromDate:date]; 
NSInteger yourRequiredValue=[components day]; //day, month, week etc