如何解析字符串到DateTime？(How to parse string to DateTime?)

如何解析字符串到DateTime？(How to parse string to DateTime?)

我有产品列表，每个产品都有DateTime类型的创建日期。 我想在我输入字符串类型之后创建一些产品。

我以字符串类型输入EnteredDate ，如下所示： 05/16/2012

1. var dates = from d in Products 2. where d.CreateDate >= DateTime.ParseExact( EnteredDate, "mm/dd/yy", null ) 3. select d;

在第二行中，我得到错误，因为字符串未被识别为“mm / dd / yy” 的有效日期时间。 我也尝试过DateTime.Parse（），Convert.ToDateTime（）并得到相同的错误。 我如何通过创建日期来过滤此产品列表？

I have product list and every product has create date in DateTime type. I want to take some products that created after my entering time in string type.

I enter EnteredDate in string type, like this format : 05/16/2012

1. var dates = from d in Products 2. where d.CreateDate >= DateTime.ParseExact( EnteredDate, "mm/dd/yy", null ) 3. select d;

In second line I got error as String was not recognized as a valid DateTime for "mm/dd/yy". I also tried DateTime.Parse(), Convert.ToDateTime() and got same error. How can I filter this product list by create date?

最满意答案

“mm”是分钟，而你的年份是4位数字，而不是2.如果你的格式真的是这样，你想要“MM / dd / yyyy”。 你在这方面有多自信？ （特别是，如果它是由用户输入的，你应该让你的代码对文化敏感......）

我建议将解析部分从查询中拉出来，如果你确实有固定的格式，也可能使用不变的文化进行解析：

DateTime date = DateTime.ParseExact(EnteredDate, "MM/dd/yyyy", CultureInfo.InvariantCulture); var dates = Products.Where(d => d.CreateDate >= date);

"mm" is minutes, and your year is 4 digits, not 2. You want "MM/dd/yyyy", if your format is really always that. How confident are you on that front? (In particular, if it's entered by a user, you should probably make your code culture-sensitive...)

I would suggest pulling the parsing part out of the query though, and also probably using the invariant culture for parsing if you've really got a fixed format:

DateTime date = DateTime.ParseExact(EnteredDate, "MM/dd/yyyy", CultureInfo.InvariantCulture); var dates = Products.Where(d => d.CreateDate >= date);