ScriptComponent.PreExecute 方法
Executes custom code that must run before the Script component has processed its inputs and outputs.
命名空间： Microsoft.SqlServer.Dts.Pipeline
程序集： Microsoft.SqlServer.TxScript（在 Microsoft.SqlServer.TxScript.dll 中）
语法
声明
Public Overridable Sub PreExecute
用法
Dim instance As ScriptComponent
instance.PreExecute()
public virtual void PreExecute()
public:
virtual void PreExecute()
abstract PreExecute : unit -> unit
override PreExecute : unit -> unit
public function PreExecute()
注释
The Script component developer does not use the ScriptComponent class directly, but indirectly, by coding the methods and properties of the ScriptMain class, which inherits from ScriptComponent through the UserComponent class.
The developer can override the PreExecute method to perform any one-time tasks necessary before processing the rows of data.
示例
The following code sample demonstrates how the Script component developer might use the PreExecute and PostExecute methods to open and close a text file connection before and after processing. For more information on this sample, see 使用脚本组件创建目标.
Imports System.IO
...
Public Class ScriptMain
Inherits UserComponent
Dim copiedAddressFile As String
Private textWriter As StreamWriter
Private columnDelimiter As String = ","
Public Overrides Sub AcquireConnections(ByVal Transaction As Object)
Dim connMgr As IDTSConnectionManager100 = _
Me.Connections.MyFlatFileDestConnectionManager
copiedAddressFile = CType(connMgr.AcquireConnection(Nothing), String)
End Sub
Public Overrides Sub PreExecute()
textWriter = New StreamWriter(copiedAddressFile, False)
End Sub
Public Overrides Sub MyAddressInput_ProcessInputRow(ByVal Row As MyAddressInputBuffer)
With textWriter
If Not Row.AddressID_IsNull Then
.Write(Row.AddressID)
End If
.Write(columnDelimiter)
If Not Row.City_IsNull Then
.Write(Row.City)
End If
.WriteLine()
End With
End Sub
Public Overrides Sub PostExecute()
textWriter.Close()
End Sub
End Class