Question

我在将字符串转换为我需要的日期格式时遇到问题。我想要转换的字符串的一个示例是215056081909.我想将该字符串转换为08/19/09 21:50:56。

下面列出的代码是我尝试用于转换过程的代码。当我运行代码时，我收到下面的错误，我很确定这是因为我的字符串在军事（24小时）时间内有时间部分。任何人都可以帮我把字符串转换成我需要的格式吗？

谢谢！

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

由于您的完全格式，您可以使用DateTime.ParseExact提供格式和输入数据来尝试转换日期：

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

如果输入可能格式错误，您可以考虑使用DateTime.TryParseExact：

Dim theDate As DateTime
If DateTime.TryParseExact("215056081909", _
                          "HHmmssMMddyy", _
                          CultureInfo.CurrentCulture, _
                          DateTimeStyles.None, _
                          theDate)) Then
    ' Parsing succeeded, and theDate will contain the parsed date
End If

Answer 2

我相信VB.NET字符串是基于0的。你最右边的子串从11开始，长度为2. 11 + 2 == 13

Answer 3

如上所述，您的错误在于使用1-base而不是0-based索引。

请尝试以下索引......

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

我认为您应该使用DateTime.TryParse，因为如果转换为日期失败，此函数不会抛出异常，它将返回true或false，具体取决于是否成功转换。

Answer 5

为什么要通过“string-＆gt; convert”方法？使用long构造函数： http://msdn.microsoft.com/en-us/library/aa326687%28VS.71%29.aspx

如果需要，您可以解析各个部分并转换为整数，但它会更加明确并且应该更快，因为convert方法需要执行相同的解析方法。

Answer 6

尝试DateTime.ParseExact（“215056081909”，“HHmmssMMddyy”）。ToString（“MM / dd / yy HH：mm：ss”）

从文本字符串创建日期 - VB.Net

6 个答案: