混合1.1和2.0环境中的问题转换 [英] Problem casting in mixed 1.1 and 2.0 environment
问题描述
我有一个令人讨厌的问题，因为我在一个2.0应用程序中包含了一个已创建的DAL中的一个强制转换器。$ / $
我们系统中的每个存储过程使用整数参数来返回错误
代码。以下代码在1.1应用程序中运行良好，从我在完全2.0应用程序中制作的测试应用程序
。但是，当我尝试使用来自2.0应用程序的DAL时，
使用1.1编译的DAL，以下转换会抛出无效的转换
异常（System.InvalidCastException：Specified cast无效。）
cmdToExecute.Parameters.Add（new SqlParameter（" @ iErrorCode"，SqlDbType.Int，
4，ParameterDirection.Output ，true，10,0，"，，DataRowVersion.Proposed，
_errorCode））;
con.Open（）;
//执行查询。
adapter.Fill（toReturn）;
_errorCode =（Int32）cmdToExecute.Parameters [" @ iErrorCode" ] .Value;
是否有人能够确认这是否是框架中的错误，预期
行为或其他？
问候
Mark
Hi,
I have this annoying problem with a cast failing from a DAL that was created
in 1.1 that I have included in a 2.0 app.
Every stored proc in our system uses an integer parameter to return an error
code. The following code works fine in 1.1 apps, and from a test app I made
in fully 2.0 apps. However, when I try to use the DAL from a 2.0 app that
uses the 1.1 compiled DAL, the following cast throws an invalid cast
exception (System.InvalidCastException: Specified cast is not valid.)
cmdToExecute.Parameters.Add(new SqlParameter("@iErrorCode", SqlDbType.Int,
4, ParameterDirection.Output, true, 10, 0, "", DataRowVersion.Proposed,
_errorCode));
con.Open();
// Execute query.
adapter.Fill(toReturn);
_errorCode = (Int32)cmdToExecute.Parameters["@iErrorCode"].Value;
Is anyone able to confirm if this is a bug in the Framework, expected
behaviour, or otherwise?
Regards
Mark
推荐答案
" Tyler Durden" < MS ******** @ aspect.com.au>在留言新闻中写道：5D ********************************** @ microsof t.com ...
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cmdToExecute.Parameters.Add（new SqlParameter（" @ iErrorCode"，SqlDbType.Int，
:: _ _ errorCode =（Int32）cmdToExecute.Parameters [" @ iErrorCode"]。Value;
是否有人能够确认这是否是框架中的错误，预期的行为或其他？
cmdToExecute.Parameters.Add(new SqlParameter("@iErrorCode", SqlDbType.Int, : : _errorCode = (Int32)cmdToExecute.Parameters["@iErrorCode"].Value;
Is anyone able to confirm if this is a bug in the Framework, expected
behaviour, or otherwise?
当发生什么时候会发生什么？你说，
cmdToExecute.Parameters [" @ iErrorCode"]。Value.GetType（）.FullName
？
我相信在.NET 2.0下，这将永远是一个SqlInt32（它是Nullable，在2.0中是一个新的概念
，因此它是否具有DBNull值，它总是
是这个特定类型），区别于.NET 1.x，其中此参数
值可以是Int32或DBNull.Value（即，打字在空中
我认为这导致了不那么强烈的打击，效率低下nt IL in 1.x.）
Derek Harmon
What happens when you say,
cmdToExecute.Parameters["@iErrorCode"].Value.GetType( ).FullName
?
I believe under .NET 2.0, this will always be a SqlInt32 (which is Nullable, a
new concept in 2.0, thus whether it has a DBNull value or not, it will always
be this one specific type), distinguished from .NET 1.x where this parameter
value could be an Int32 or a DBNull.Value (i.e., the typing was up in the air
and I believe this led to less strongly-typed, less-efficient IL in 1.x.)
Derek Harmon
嗨Derek
如果我理解正如你所说的那样，我认为这意味着演员在2.0环境下也无法工作。事实是它在一个完全1.1编译的应用程序中，以及在完全2.0
编译的应用程序中确实有效，但在使用两者的混合时则不行。
因此，根据您的回复，我会假设由于更强的输入规则，该类型的演员将在2.0框架中不成功。或者是
我错过了什么？
问候，
马克
" ; Derek Harmon写道：
Hi Derek
If I understand what you are saying correctly, I would think that would mean
the cast would not work in the 2.0 environment either. The fact is that it
does work when in a completely 1.1 compiled app, and also in a completely 2.0
compiled app, but not when use a mixture of both.
Therefore, from your response I would assume that a cast of that type would
not succeed in the 2.0 framework because of the stronger typing rules. Or am
I missing something?
Regards,
Mark
"Derek Harmon" wrote:
" Tyler Durden" < MS ******** @ aspect.com.au>在留言新闻中写道：5D ********************************** @ microsof t.com ...
"Tyler Durden" <ms********@aspect.com.au> wrote in message news:5D**********************************@microsof t.com...
cmdToExecute.Parameters.Add（new SqlParameter（" @ iErrorCode"，SqlDbType.Int，
cmdToExecute.Parameters.Add(new SqlParameter("@iErrorCode", SqlDbType.Int,
::
: :
_errorCode =（Int32）cmdToExecute。参数[" @ iErrorCode"]。值;
是否有人能够确认这是否是框架中的错误，预期的行为或其他？
_errorCode = (Int32)cmdToExecute.Parameters["@iErrorCode"].Value;
Is anyone able to confirm if this is a bug in the Framework, expected
behaviour, or otherwise?
当你说，
cmdToExecute.Parameters [" @ iErrorCode"]时会发生什么.Value.GetType（）。FullName
？
我相信在.NET 2.0下，这将永远是一个SqlInt32（它是Nullable，是2.0中的一个新概念，因此它是否具有DBNull值，它总是会成为这一个特定的类型），区别于.NET 1.x，其中此参数值可以是Int32或DBNull.Value（即打字在空中
我相信这导致不太强烈的类型，更少的e 1.x中的有效IL。）
Derek Harmon
What happens when you say,
cmdToExecute.Parameters["@iErrorCode"].Value.GetType( ).FullName
?
I believe under .NET 2.0, this will always be a SqlInt32 (which is Nullable, a
new concept in 2.0, thus whether it has a DBNull value or not, it will always
be this one specific type), distinguished from .NET 1.x where this parameter
value could be an Int32 or a DBNull.Value (i.e., the typing was up in the air
and I believe this led to less strongly-typed, less-efficient IL in 1.x.)
Derek Harmon
Derek，
SqlInt32在2.0之前的框架中，它与
Nullable< int>不同。 SqlInt32是一个非常相似的结构，但不是与2.0中的Nullable类型相同的
。
-
- Nicholas Paldino [.NET / C＃MVP]
- mv*@spam.guard.caspershouse.com
" Derek Harmon" <螺******* @ msn.com>在消息中写道
news：Ou ************** @ TK2MSFTNGP14.phx.gbl ...
Derek,
SqlInt32 was in the framework before 2.0, and it is different from a
Nullable<int>. SqlInt32 is a structure that is very similar, but not the
same as what is considered a Nullable type in 2.0.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com
"Derek Harmon" <lo*******@msn.com> wrote in message
news:Ou**************@TK2MSFTNGP14.phx.gbl...
" Tyler Durden" < MS ******** @ aspect.com.au>在消息中写道
新闻：5D ********************************** @ microsof t.com。 ..
"Tyler Durden" <ms********@aspect.com.au> wrote in message
news:5D**********************************@microsof t.com...
cmdToExecute.Parameters.Add（new SqlParameter（" @ iErrorCode"，
SqlDbType.Int，
cmdToExecute.Parameters.Add(new SqlParameter("@iErrorCode",
SqlDbType.Int,
::
: :
_errorCode =（Int32）cmdToExecute.Parameters [" @ iErrorCode"]。值;
是否有人能够确认这是否是框架中的错误，预期的行为或其他行为？
_errorCode = (Int32)cmdToExecute.Parameters["@iErrorCode"].Value;
Is anyone able to confirm if this is a bug in the Framework, expected
behaviour, or otherwise?
当你说，
cmdToExecute.Parameters [" @ iErrorCode"]时会发生什么.Value.GetType（）。FullName
？
我相信在.NET 2.0下，这将永远是一个SqlInt32（它是Nullable，在2.0中是一个新概念，因此它是否有一个DBNull是否值，它将始终是这一特定类型），区别于.NET 1.x，其中此值
值可以是Int32或DBNull.Value （即，打字在
空中
我相信这一点导致1.x中强度较低，效率较低的IL。）
Derek Harmon
What happens when you say,
cmdToExecute.Parameters["@iErrorCode"].Value.GetType( ).FullName
?
I believe under .NET 2.0, this will always be a SqlInt32 (which is
Nullable, a
new concept in 2.0, thus whether it has a DBNull value or not, it will
always
be this one specific type), distinguished from .NET 1.x where this
parameter
value could be an Int32 or a DBNull.Value (i.e., the typing was up in the
air
and I believe this led to less strongly-typed, less-efficient IL in 1.x.)
Derek Harmon
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