string input;
DateTime db;
Console.WriteLine("Enter Date in this Format(YYYY-MM-DD): ");
input = Console.ReadLine();
db = Convert.ToDateTime(input);

//////// this methods convert string value to datetime
///////// in order to print date

Console.WriteLine("{0}-{1}-{2}",db.Year,db.Month,db.Day);

试试这个

DateTime myDate = DateTime.Parse(dateString);

一个更好的方法是:

DateTime myDate;
if (!DateTime.TryParse(dateString, out myDate))
{
    // handle parse failure
}

似乎没有人实现过扩展方法。通过@CMS的回答:

工作和改进的完整源代码示例在这里:Gist Link

namespace ExtensionMethods {
    using System;
    using System.Globalization;

    public static class DateTimeExtensions {
        public static DateTime ToDateTime(this string s, 
                  string format = "ddMMyyyy", string cultureString = "tr-TR") {
            try {
                var r = DateTime.ParseExact(
                    s: s,
                    format: format,
                    provider: CultureInfo.GetCultureInfo(cultureString));
                return r;
            } catch (FormatException) {
                throw;
            } catch (CultureNotFoundException) {
                throw; // Given Culture is not supported culture
            }
        }

        public static DateTime ToDateTime(this string s, 
                    string format, CultureInfo culture) {
            try {
                var r = DateTime.ParseExact(s: s, format: format, 
                                        provider: culture);
                return r;
            } catch (FormatException) {
                throw;
            } catch (CultureNotFoundException) {
                throw; // Given Culture is not supported culture
            }

        }

    }
}

namespace SO {
    using ExtensionMethods;
    using System;
    using System.Globalization;

    class Program {
        static void Main(string[] args) {
            var mydate = "29021996";
            var date = mydate.ToDateTime(format: "ddMMyyyy"); // {29.02.1996 00:00:00}

            mydate = "2016 3";
            date = mydate.ToDateTime("yyyy M"); // {01.03.2016 00:00:00}

            mydate = "2016 12";
            date = mydate.ToDateTime("yyyy d"); // {12.01.2016 00:00:00}

            mydate = "2016/31/05 13:33";
            date = mydate.ToDateTime("yyyy/d/M HH:mm"); // {31.05.2016 13:33:00}

            mydate = "2016/31 Ocak";
            date = mydate.ToDateTime("yyyy/d MMMM"); // {31.01.2016 00:00:00}

            mydate = "2016/31 January";
            date = mydate.ToDateTime("yyyy/d MMMM", cultureString: "en-US"); 
            // {31.01.2016 00:00:00}

            mydate = "11/شعبان/1437";
            date = mydate.ToDateTime(
                culture: CultureInfo.GetCultureInfo("ar-SA"),
                format: "dd/MMMM/yyyy"); 
         // Weird :) I supposed dd/yyyy/MMMM but that did not work !?$^&*

            System.Diagnostics.Debug.Assert(
               date.Equals(new DateTime(year: 2016, month: 5, day: 18)));
        }
    }
}

string input;
DateTime db;
Console.WriteLine("Enter Date in this Format(YYYY-MM-DD): ");
input = Console.ReadLine();
db = Convert.ToDateTime(input);

//////// this methods convert string value to datetime
///////// in order to print date

Console.WriteLine("{0}-{1}-{2}",db.Year,db.Month,db.Day);

如果您不确定输入值，也可以如下所示使用DateTime.TryParseExact()。

DateTime outputDateTimeValue;
if (DateTime.TryParseExact("2009-05-08 14:40:52,531", "yyyy-MM-dd HH:mm:ss,fff", System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out outputDateTimeValue))
{
    return outputDateTimeValue;
}
else
{
    // Handle the fact that parse did not succeed
}

我尝试了各种方法。对我有用的是:

Convert.ToDateTime(data, CultureInfo.InvariantCulture);

我的数据是2017年9月24日上午9:31:34