使用 using 语句的 Sqldatareader 会返回输出参数吗？
以下是一个较大函数的简单代码片段作为示例。
Using conn as New SqlConnection("conn string")
Using find as new SqlCommand("ExampleProc",conn)
Dim rParam as new SqlParameter("@RESULT",SqlDbType.Int)
rParam.Direction = ParameterDirection.Output
find.Pareameters.Add(rParam)
Using f as SqlDataReader = find.ExecuteReader
'Do stuff with datareader
End Using
updateResult.Success = Convert.ToBoolean(find.Parameters("@RESULT").Value)
End Using
End Using
我知道 SqlDataReader 关闭后会返回 Output 参数。据我所知，Using 语句将调用 SqlDataReader 上的 .Dispose，那么这会基本上消除 Output 参数吗？如果是这样，调用还包含正确关闭和处理所有内容的输出参数的 SqlDataReader 的最佳方法是什么？我在网上搜索时找不到任何具体信息或示例。谢谢！
让我补充一点，根据我所读到的内容，在 SqlDataReader 上调用 .Close 后，您只能使用 SqlDataReader 访问输出参数。
Here's a simple code snippet of a larger function as an example.
Using conn as New SqlConnection("conn string")
Using find as new SqlCommand("ExampleProc",conn)
Dim rParam as new SqlParameter("@RESULT",SqlDbType.Int)
rParam.Direction = ParameterDirection.Output
find.Pareameters.Add(rParam)
Using f as SqlDataReader = find.ExecuteReader
'Do stuff with datareader
End Using
updateResult.Success = Convert.ToBoolean(find.Parameters("@RESULT").Value)
End Using
End Using
I know the Output parameter is returned after the SqlDataReader is closed. From what I think I know, the Using statement will call .Dispose on the SqlDataReader, so will that basically wipe out the Output parameter? If so, what is the best method to call a SqlDataReader that also contains Output parameters that closes and disposes everything correctly? I couldn't find any specific info or examples online in my searching. Thanks!
Let me add that based on what I've read you only have access to the Output parameter using a SqlDataReader after you call .Close on the SqlDataReader.
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您实际上只需要输出参数中返回的值。
您可以将该值复制到在
Using块外部声明的变量并返回该变量，或者在您有权访问该值后立即返回该值。You really only need the value returned in the output parameter.
You can copy the value to a variable declared outside the
Usingblock and return that, or return the value directly, as soon as you have access to it.不确定我明白你想要实现什么，但这似乎是一个更好的方法
你在
Using语句中读取结果，如果有任何失败，你将其预设为 false...not sure that I understand what you want to achieve but this seems a better approach
You read the result within the
Usingstatement and if anything fails you preset it to false...