我如何驗證日期以不同的格式

Question

我有一個正則表達式的有效日期是如下

^(((0[1-9]|[12]\d|3[01])\/(0[13578]|1[02])\/((19|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|30)\/(0[13456789]|1[012])\/((19|[2-9]\d)\d{2}))|((0[1-9]|1\d|2[0-8])\/02\/((19|[2-9]\d)\d{2}))|(29\/02\/((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))))$

但是，這將有效的，如果我輸入如下20/03/2012日期。隨着同我想補充不同的驗證，可以爲下一起工作

20032012 (ddmmyyyy)03202012(mmddyyyy)

有人能幫助我

Answer 1

使用DateTime.TryParseExact - 有一個重載需要一個格式字符串數組，因此您可以提供所有可能的格式。

從MSDN - DateTime.TryParseExact Method (String, String[], IFormatProvider, DateTimeStyles, DateTime)：

string[] formats= {"M/d/yyyy h:mm:ss tt", "M/d/yyyy h:mm tt", 
        "MM/dd/yyyy hh:mm:ss", "M/d/yyyy h:mm:ss", 
        "M/d/yyyy hh:mm tt", "M/d/yyyy hh tt", 
        "M/d/yyyy h:mm", "M/d/yyyy h:mm", 
        "MM/dd/yyyy hh:mm", "M/dd/yyyy hh:mm"}; 
string[] dateStrings = {"5/1/2009 6:32 PM", "05/01/2009 6:32:05 PM", 
         "5/1/2009 6:32:00", "05/01/2009 06:32", 
         "05/01/2009 06:32:00 PM", "05/01/2009 06:32:00"}; 
DateTime dateValue; 

foreach (string dateString in dateStrings) 
{ 
    if (DateTime.TryParseExact(dateString, formats, 
           new CultureInfo("en-US"), 
           DateTimeStyles.None, 
           out dateValue)) 
     Console.WriteLine("Converted '{0}' to {1}.", dateString, dateValue); 
    else 
     Console.WriteLine("Unable to convert '{0}' to a date.", dateString); 
} 
// The example displays the following output: 
//  Converted '5/1/2009 6:32 PM' to 5/1/2009 6:32:00 PM. 
//  Converted '05/01/2009 6:32:05 PM' to 5/1/2009 6:32:05 PM. 
//  Converted '5/1/2009 6:32:00' to 5/1/2009 6:32:00 AM. 
//  Converted '05/01/2009 06:32' to 5/1/2009 6:32:00 AM. 
//  Converted '05/01/2009 06:32:00 PM' to 5/1/2009 6:32:00 PM. 
//  Converted '05/01/2009 06:32:00' to 5/1/2009 6:32:00 AM.