C# 该字符串未被识别为有效的 DateTime。从索引 0 开始有一个未知单词
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The string was not recognized as a valid DateTime. There is an unknown word starting at index 0
提问by user541597
I have the following C# that is giving me the error above when trying to parse string to datetime.
我有以下 C#，它在尝试将字符串解析为日期时间时给了我上面的错误。
DateTime backupdate = System.Convert.ToDateTime(imageflowlabel.Text);
DateTime currentdate = System.DateTime.Now.AddHours(-2);
int result = currentdate.CompareTo(backupdate);
imageflowlable.textlooks like this 2012-04-15 15:23:34:123
imageflowlable.text看起来像这样 2012-04-15 15:23:34:123
Any ideas on how to convert this?
关于如何转换这个的任何想法？
Thanks
谢谢
采纳答案by paulsm4
Yes - use "DateTime.ParseExact()" or "TryParseExact()" with a custom format string:
是 - 使用带有自定义格式字符串的“DateTime.ParseExact()”或“TryParseExact()”：
http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx
http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx
DateTime currentdate;
int result;
try
{
// EXAMPLE: 2012-04-15 15:23:34:123
DateTime backupdate =
DateTime.ParseExact (
"yyyy-MM-dd HH:mm:ss:fff", //mind the casing
imageflowlabel.Text,
CultureInfo.InvariantCulture);
currentdate = System.DateTime.Now.AddHours(-2);
result = currentdate.CompareTo(backupdate);
}
catch (Exception ex)
{
...
回答by Austin Salonen
ParseExactshould work for you, assuming your users have no way of editing that value on their own; in that case, you should use TryParseExactto unless you want the FormatException.
ParseExact应该适合您，假设您的用户无法自行编辑该值；在这种情况下，您应该使用TryParseExact，除非您想要FormatException.
var toParse = "2012-04-15 15:23:34:123";
var parsed = DateTime.ParseExact(toParse, "yyyy-MM-dd HH:mm:ss:fff", null);
Assert.AreEqual(new DateTime(2012, 4, 15, 15, 23, 34, 123), parsed);
回答by Douglas
Your code looks correct; the issue is presumably with your string format, whose last :should actually be a .(indicating the start of the fractional seconds).
你的代码看起来是正确的；问题可能与您的字符串格式有关，其最后一个:实际上应该是 a .（表示小数秒的开始）。
Incorrect: 2012-04-15 15:23:34:123
Correct: 2012-04-15 15:23:34.123
Convert.ToDateTime("2012-04-15 15:23:34.123")works fine.
Convert.ToDateTime("2012-04-15 15:23:34.123")工作正常。
回答by madeFromCode
Your problem is with the time part of your dateTime string. If your string read "2012-04-15 15:23:34.123" then it would work. You could modify your string and replace the last colon with a period and that would fix it.
您的问题出在 dateTime 字符串的时间部分。如果您的字符串显示为“2012-04-15 15:23:34.123”，则它会起作用。您可以修改字符串并用句点替换最后一个冒号，这样就可以解决问题。
回答by Edward
I have seen several answers to resolve the situation outlined in this question such as using DateTime.Parse, DateTime.ParseExact, or Convert.ToDateTime. I am trying to determine why the problem is seemlingly inconsistent. I built an application using the Microsoft Enterprise Library Software Factory with a SQL Server 2008 R2 backend and it has been in production for about 9 months now. It has at least 20 instances with the same code format that assign DateTime property values from C# to System.Data.DBType.DateTime parameters for stored procedures. 19 of the 20 code blocks work fine. For the 20th I had to add the .ToString() call as shown below to resolve the error mentioned in this question.
我已经看到了几个解决此问题中概述的情况的答案，例如使用 DateTime.Parse、DateTime.ParseExact 或 Convert.ToDateTime。我试图确定为什么问题似乎不一致。我使用 Microsoft Enterprise Library Software Factory 和 SQL Server 2008 R2 后端构建了一个应用程序，它已经投入生产大约 9 个月了。它至少有 20 个具有相同代码格式的实例，将 C# 中的 DateTime 属性值分配给存储过程的 System.Data.DBType.DateTime 参数。20 个代码块中的 19 个工作正常。对于 20 日，我不得不添加如下所示的 .ToString() 调用来解决这个问题中提到的错误。
db.AddInParameter(command, "beginDT", DbType.DateTime, timeBlock.BeginDT.ToString());
So anyone have some insight on why would it work fine in 19 absolutely identical instances and not in the 20th? I am just trying to get more of an understanding of the inter-relationship of these objects so I can build solid code. I have since gone back to all other instances and added the .ToString() call. Haven't completed my regression testing though; so, I don't know if that was a mistake.
所以有人对为什么它在 19 个完全相同的实例中可以正常工作而不是在 20 个实例中正常工作有一些见解？我只是想更多地了解这些对象的相互关系，以便我可以构建可靠的代码。我已经回到所有其他实例并添加了 .ToString() 调用。还没有完成我的回归测试；所以，我不知道那是不是一个错误。
