英文:
get last 12 months dates in flutter
问题
我正在创建一个自定义的月份选择器，它会给出过去12个月的列表。
比如现在是8月，它应该返回以下日期列表：
2023年8月、2023年7月、2023年6月、2023年5月......2022年9月
我已经创建了以下的自定义函数，但是不知道如何减去一个月：
List<DateTime> getMonths() {
final dates = <DateTime>[];
final now = DateTime.now();
int number_of_months = DateTime.now().month + 12;
DateTime date = DateTime.now();
for(int x = 0; x < number_of_months; x++) {
dates.add(date);
// 在这里如何减去一个月？
date = ???
}
return dates;
}
请帮我解决如何减去一个月的问题。
英文:
I am creating a custom month picker where it gives a list of last 12 months
Like its Auguest so it should return list of dates like
Aug 2023,July 2023,June 2023, May 2023,.........sept 2022
i have created a UDF as following but missing how to deduct a month
List<DateTime> getMonths() {
final dates = <DateTime>[];
final now = DateTime.now();
int number_of_months=DateTime.now().month+12;
DateTime date=DateTime.now();
for(int x=0;x<number_of_months;x++)
{
dates.add(date);
date=??? //how to deduct one month here from date
}
return dates;
}
答案1
得分: 1
要获取一个减去月份的新DateTime，可以按照以下方式操作：
List<DateTime> getLast12Months() {
List<DateTime> dates = [];
final today = DateTime.now();
for (int x = 0; x < 12; x++) {
dates.add(DateTime(today.year, today.month - x, 1));
}
return dates;
}
在上面的代码中，可以看到在for循环中，我们只是从today日期的月份中减去循环值，并创建一个新的DateTime对象。
你将会得到以下输出：
[
2023-08-01 00:00:00.000,
2023-07-01 00:00:00.000,
2023-06-01 00:00:00.000,
2023-05-01 00:00:00.000,
2023-04-01 00:00:00.000,
2023-03-01 00:00:00.000,
2023-02-01 00:00:00.000,
2023-01-01 00:00:00.000,
2022-12-01 00:00:00.000,
2022-11-01 00:00:00.000,
2022-10-01 00:00:00.000,
2022-09-01 00:00:00.000
]
你可以使用Intl包根据你的需求格式化日期。
英文:
To get a new DateTime with deducted month, you can do as
List<DateTime> getLast12Months() {
List<DateTime> dates = [];
final today = DateTime.now();
for (int x = 0; x < 12; x++) {
dates.add(DateTime(today.year, today.month - x, 1));
}
return dates;
}
Here, as you can see in the for loop, we are just deducting the loop value from the month in today date and creating a new DateTime
You will get output as following:
[
2023-08-01 00:00:00.000,
2023-07-01 00:00:00.000,
2023-06-01 00:00:00.000,
2023-05-01 00:00:00.000,
2023-04-01 00:00:00.000,
2023-03-01 00:00:00.000,
2023-02-01 00:00:00.000,
2023-01-01 00:00:00.000,
2022-12-01 00:00:00.000,
2022-11-01 00:00:00.000,
2022-10-01 00:00:00.000,
2022-09-01 00:00:00.000
]
You can use Intl package to format the date as per your need.
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