iOS：从日期问题获取 weekOfMonth答案

【问题标题】：iOS: getting weekOfMonth from date issueiOS：从日期问题获取 weekOfMonth
【发布时间】：2016-07-26 07:40:10
【问题描述】：

从日期获取WeekOfMonth 存在一个小问题。这是一个示例代码。

NSDateFormatter *dateformate=[[NSDateFormatter alloc]init];
[dateformate setDateFormat:@"dd/MM/yyyy"]; // Date formater

NSDate *dateTest1 = [dateformate dateFromString:@"25/07/2016"]; //Week no: 5
NSDate *dateTest2 = [dateformate dateFromString:@"01/08/2016"]; //Week no: 1
NSDate *dateTest3 = [dateformate dateFromString:@"08/08/2016"]; //Week no: 2
NSDate *dateTest4 = [dateformate dateFromString:@"15/08/2016"]; //Week no: 3
NSDate *dateTest5 = [dateformate dateFromString:@"22/08/2016"]; //Week no: 4
NSDate *dateTest6 = [dateformate dateFromString:@"29/08/2016"]; //Week no: 5
NSDate *dateTest7 = [dateformate dateFromString:@"05/09/2016"]; //Week no: 6

components = [calendar components:NSCalendarUnitWeekOfMonth fromDate:dateTest1];
dateString = [dateformate stringFromDate:dateTest1];
NSLog(@"dateTest1 -> %@",dateString); //output : dateTest1 -> 25/07/2016
NSLog(@"Week no: %ld",(long)[components weekOfMonth]); //output : Week no: 4

components = [calendar components:NSCalendarUnitWeekOfMonth fromDate:dateTest2];
dateString = [dateformate stringFromDate:dateTest2];
NSLog(@"dateTest2 -> %@",dateString); //output : dateTest2 -> 01/08/2016
NSLog(@"Week no: %ld",(long)[components weekOfMonth]); //output : Week no: 1

components = [calendar components:NSCalendarUnitWeekOfMonth fromDate:dateTest3];
dateString = [dateformate stringFromDate:dateTest3];
NSLog(@"dateTest3 -> %@",dateString); //output : dateTest3 -> 08/08/2016
NSLog(@"Week no: %ld",(long)[components weekOfMonth]); //output : Week no: 2

components = [calendar components:NSCalendarUnitWeekOfMonth fromDate:dateTest4];
dateString = [dateformate stringFromDate:dateTest4];
NSLog(@"dateTest4 -> %@",dateString); //output : dateTest4 -> 15/08/2016
NSLog(@"Week no: %ld",(long)[components weekOfMonth]); //output : Week no: 3

components = [calendar components:NSCalendarUnitWeekOfMonth fromDate:dateTest5];
dateString = [dateformate stringFromDate:dateTest5];
NSLog(@"dateTest5 -> %@",dateString); //output : dateTest5 -> 22/08/2016
NSLog(@"Week no: %ld",(long)[components weekOfMonth]); //output : Week no: 4

components = [calendar components:NSCalendarUnitWeekOfMonth fromDate:dateTest6];
dateString = [dateformate stringFromDate:dateTest6];
NSLog(@"dateTest6 -> %@",dateString); //output : dateTest6 -> 29/08/2016
NSLog(@"Week no: %ld",(long)[components weekOfMonth]); //output : Week no: 5

components = [calendar components:NSCalendarUnitWeekOfMonth fromDate:dateTest7];
dateString = [dateformate stringFromDate:dateTest7];
NSLog(@"dateTest7 -> %@",dateString); //output : dateTest7 -> 05/09/2016
NSLog(@"Week no: %ld",(long)[components weekOfMonth]); //output : Week no: 2

如您所见，dateTest1 应该是 Week no = 5 而不是 Week no = 4。正如我所见和你所见，其他日期没有问题。

我需要正确的WeekOfMonth 来正确设置我的FFCalendar https://github.com/fggeraissate/FFCalendar

【问题讨论】：

标签： ios xcode calendar nsdate ios9.2

【解决方案1】：

let calendar = NSCalendar.currentCalendar()
let dateComponent = calendar.components([.WeekOfYear, .Day, .Month, .Year], fromDate: NSDate(timeIntervalSinceNow: 0))
print("weekOfYear \(dateComponent.weekOfYear)")

使用上面的代码，您可以获得 weekOfYear。现在您需要计算该月第一个日期的 weekOfYear 和您需要查找的日期。现在为了得到 weekOfMonth 得到两个 WeekOfYear 的 diff + 1

【讨论】：

感谢您的回答。使用 weekOfMonth 不取决于我，它取决于 FFCalendar。在方法 dateChanged 上的 FFWeekCalendarView 上，我需要正确设置 WeekOfMonth，因为它适用于 WeekOfMonth。我认为我不能在 FFCalendar 中使用 weekOfYear 代替 weekOfMonth。
对不起，我明白了！它工作得很好。谢谢
每月返回 1-4 或第 5 周，一年中的第几周应返回 1-52 或 53

【解决方案2】：

按照 raj-agrawal 提出的解决方案，我提出了这个运行良好的解决方案

NSDate *date = [[FFDateManager sharedManager] currentDate];

NSDateFormatter *dateformate=[[NSDateFormatter alloc]init];
[dateformate setDateFormat:@"dd/MM/yyyy"]; // Date formater

NSString *dateString = [dateformate stringFromDate:date];
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDateComponents* dateComponent = [calendar components:NSWeekOfYearCalendarUnit|NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:date];
NSInteger weekOfYearCurrent =(long)[dateComponent weekOfYear];
dateString = [dateformate stringFromDate:date];
NSLog(@"dateCurrent -> %@",dateString);
NSLog(@"weekOfYearCurrent: %ld",(long)weekOfYearCurrent);

NSDate *dateFirstMonth = [dateformate dateFromString:[NSString stringWithFormat:@"01/%d/2016", (int)[dateComponent month]]];
dateComponent = [calendar components:NSWeekOfYearCalendarUnit|NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:dateFirstMonth];
NSInteger weekOfYearFirstDayOfMonth =(long)[dateComponent weekOfYear];
dateString = [dateformate stringFromDate:dateFirstMonth];
NSLog(@"dateFirstMonth -> %@",dateString);
NSLog(@"weekOfYearFirstDayOfMonth: %ld",(long)weekOfYearFirstDayOfMonth);

NSInteger NumberWeekOfMonth = (weekOfYearCurrent - weekOfYearFirstDayOfMonth) + 1;
NSLog(@"NumberWeekOfMonth: %ld",(long)NumberWeekOfMonth);

【讨论】：