vb初学者

[cymandhxl]

Public Shared Function DeleteUserReportAuthorization(ByVal index As Integer, Optional ByVal trans As SqlTransaction = Nothing) As Integer
Dim retVal As Integer
Dim conPortal As SqlConnection
Dim sqlCmd As SqlCommand

Dim outerTrans As Boolean

If trans Is Nothing Then
outerTrans = False

conPortal = New SqlConnection(HerpData.ConnectionString(HerpSubSystems.HerpCM))
sqlCmd = New SqlCommand("UserReportAuthorizationsDeleteUserReportAuthorization", conPortal)
Else
outerTrans = True

conPortal = trans.Connection
sqlCmd = New SqlCommand("UserReportAuthorizationsDeleteUserReportAuthorization", conPortal, trans)
End If

sqlCmd.CommandType = CommandType.StoredProcedure

sqlCmd.Parameters.Add("@RETURN_VALUE", SqlDbType.Int).Direction = ParameterDirection.ReturnValue

sqlCmd.Parameters.Add("@ura_id", index)

If conPortal.State = ConnectionState.Closed Then
conPortal.Open()
End If

Try
sqlCmd.ExecuteNonQuery()
Catch ex As Exception
If outerTrans = False Then conPortal.Close()
Return -1
End Try

retVal = Fix(sqlCmd.Parameters("@RETURN_VALUE").Value)
If outerTrans = False Then conPortal.Close()
Return retVal
End Function


Optional ByVal trans As SqlTransaction = Nothing) As Integer
这句是什么意思，为什么要加上事物来做为参数

[yz1199]

这个表示可选参数,也就是在调用这个函数时,trans这个参数可以不传

[ALong_Yue]

同意楼上的回答。
在调用DeleteUserReportAuthorization的时候，如果不给trans传值，会使用默认值NOTHING。

[夜雨悠扬]

Optional 是可选参数
这个东西的意思应该是如果外边有数据库连接并且打开事务的时候，为了在函数里面也可以访问数据库而作的

[copico]

Optional 关键字指示在调用过程时可以省略过程参数。