vb.net 如何使用 Date.TryParseExact 将字符串解析为日期
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How to Parse String to Date Using Date.TryParseExact
提问by r.r
readingDim lendingtimedate As String = If(irequest.Form.Contains("startingtimedate"), irequest.Form("endingtimedate").Value, "")
读Dim lendingtimedate As String = If(irequest.Form.Contains("startingtimedate"), irequest.Form("endingtimedate").Value, "")
getting value : lendingtimedate = "04/23/2014 12:45 PM"
获得价值： lendingtimedate = "04/23/2014 12:45 PM"
and now i will to parse it in
现在我将解析它
Dim edateValue As Date
as
作为
Dim enddate = Date.TryParseExact(lendingtimedate, "MM/dd/yyyy h:mm:ss tt", Globalization.CultureInfo.InvariantCulture, Globalization.DateTimeStyles.None, edateValue)
but enddate is always: edateValue = #12:00:00 AM#
但结束日期总是： edateValue = #12:00:00 AM#
please help me to find out why i cant get
请帮我找出为什么我不能得到
edateValue = "04/23/2014 12:45 PM"
回答by Matt Wilko
TryParseExactreturns a Booleanindicating whether the parse succeeded or not, so you need to test for the result.
TryParseExact返回一个Boolean指示是否解析成功，因此您需要测试结果。
In your case it is returning False because your format string did not match the format of the string you are trying to parse (you have an extra :ssthat is not required).
在您的情况下，它返回 False 因为您的格式字符串与您尝试解析的字符串的格式不匹配（您有一个:ss不需要的额外字符串）。
The following code parses correctly:
以下代码正确解析：
Dim lendingtimedate = "04/23/2014 12:45 PM"
Dim edateValue As Date
If Date.TryParseExact(lendingtimedate, "MM/dd/yyyy h:mm tt", Globalization.CultureInfo.InvariantCulture, Globalization.DateTimeStyles.None, edateValue) Then
Debug.WriteLine(edateValue)
Else
Debug.WriteLine("Failed to parse")
End If
回答by Tim Schmelter
Because there are no seconds in "04/23/2014 12:45 PM", so this does not work:
因为没有秒"04/23/2014 12:45 PM"，所以这不起作用：
"MM/dd/yyyy h:mm:ss tt"
but this:
但是这个：
"MM/dd/yyyy h:mm tt"
