System.FormatException：字符串未被识别为有效的DateTime（DateTime格式yyyyMMdd：HHmmss）

Question

I have a date time format of yyyyMMdd:HHmmss . I receive the datetime from a device and I can confirm that the format is yyyyMMdd:HHmmss .

For example I get datetime as 20180331:162308 . I tried to convert to 03/31/2018 04:23 PM format by using below code:

string localDateTime = 
  Convert.ToString(protocol.GetParameter(Parameter.localmdmdatetimestr_3043));

string formatString = "yyyyMMdd:HHmmss";

protocol.Log(
 "QA" + protocol.QActionID + "|DateTime|localDateTime" + localDateTime,
  LogType.Error, 
  LogLevel.NoLogging);

DateTime LocalDt = DateTime.ParseExact(
  localDateTime, 
  formatString, 
  CultureInfo.InvariantCulture);

But instead get

System.FormatException: String was not recognized as a valid DateTime error.

Answer 1

As per your requirement
string localDateTime = Convert.ToString("20180331:162308");

        string formatString = "yyyyMMdd:HHmmss";

        DateTime LocalDt = DateTime.ParseExact(
          localDateTime,
          formatString, CultureInfo.InvariantCulture);
        Console.WriteLine(LocalDt);
        var test = LocalDt.ToString("yyyy/MM/dd HH:mm tt", CultureInfo.InvariantCulture);
       Console.WriteLine(test);
        Console.ReadLine();