Creating a date from a text string - VB.Net

Question

I having a problem converting a string into the date format I need. An example of the string I'm trying to convert would be 215056081909. I would like to convert that string into 08/19/09 21:50:56.

The code listed below is what I'm trying to use for the conversion process. When I run the code I'm getting the error below and I'm pretty sure it's because my string has the time portion in military (24 hour) time. Could anyone help me get the string converted to the format I need?

Thank you!

Error:
System.ArgumentOutOfRangeException was unhandled
      Message="Index and length must refer to a location within the string. Parameter name: length"
      ParamName="length"
      Source="mscorlib"
      StackTrace:
           at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy)
           at System.String.Substring(Int32 startIndex, Int32 length)
           at GLTracker.PortManager.DoDataCollection(MessageType type, String msg)
           at GLTracker.PortManager.comPort_DataReceived(Object sender, SerialDataReceivedEventArgs e)
           at System.IO.Ports.SerialPort.CatchReceivedEvents(Object src, SerialDataReceivedEventArgs e)
           at System.IO.Ports.SerialStream.EventLoopRunner.CallReceiveEvents(Object state)
           at System.Threading._ThreadPoolWaitCallback.WaitCallback_Context(Object state)
           at System.Threading.ExecutionContext.runTryCode(Object userData)
           at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
           at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
           at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
           at System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(_ThreadPoolWaitCallback tpWaitCallBack)
           at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)
      InnerException:




'Code:
Dim strDateTime as string = "215056081909"

Dim dTransDate As DateTime = Convert.ToDateTime(String.Format("{0}/{1}/{2} {3}:{4}:{5}", _
                                                                strDateTime.Substring(7, 2), _
                                                                strDateTime.Substring(9, 2), _
                                                                strDateTime.Substring(11, 2), _
                                                                strDateTime.Substring(0, 2), _
                                                                strDateTime.Substring(3, 2), _
                                                                strDateTime.Substring(5, 2)))

Answer 1

I believe VB.NET strings are 0-based. Your furthest right substring starts at 11 and has length of 2. 11+2 == 13

Answer 2

Why go through the "string->convert" method? Use the long constructor: http://msdn.microsoft.com/en-us/library/aa326687%28VS.71%29.aspx

You can parse out the individual parts and convert to an integer if you want, but it'll be much more explicit and should be quicker, since the convert method needs to do the same parse methods.

Answer 3

As above, your error is in using 1-base instead of 0-based indices.

Try the following indexes instead...

Dim dTransDate As DateTime = _  
    Convert.ToDateTime(String.Format("{0}/{1}/{2} {3}:{4}:{5}", _
        strDateTime.Substring(6, 2), _
        strDateTime.Substring(8, 2), _
        strDateTime.Substring(10, 2), _
        strDateTime.Substring(0, 2), _
        strDateTime.Substring(2, 2), _
        strDateTime.Substring(4, 2)))

Answer 4

Why not just do it like this?

Dim theDate As DateTime = DateTime.ParseExact("215056081909", "HHmmssMMddyy", CultureInfo.CurrentCulture)

Answer 5

Try DateTime.ParseExact("215056081909", "HHmmssMMddyy").ToString("MM/dd/yy HH:mm:ss")

Answer 6

I think you should use the DateTime.TryParse as this function will not throw exception if the conversion to the date is failed, it will return true or false depending of whether converted successfully or not .