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SetExpression 方法

Assigns the specified expression to the property. Specify nullNothingnullptrunitnull 引用（在 Visual Basic 中为 Nothing） to remove an existing expression from the property.

命名空间：  Microsoft.SqlServer.Dts.Runtime
程序集：  Microsoft.SqlServer.ManagedDTS（在 Microsoft.SqlServer.ManagedDTS.dll 中）

语法

声明
Public Sub SetExpression ( _
    propertyName As String, _
    expression As String _
)
用法
Dim instance As ForEachEnumeratorHost
Dim propertyName As String
Dim expression As String

instance.SetExpression(propertyName, _
    expression)

public void SetExpression(
    string propertyName,
    string expression
)

public:
virtual void SetExpression(
    String^ propertyName, 
    String^ expression
) sealed

abstract SetExpression : 
        propertyName:string * 
        expression:string -> unit 
override SetExpression : 
        propertyName:string * 
        expression:string -> unit 

public final function SetExpression(
    propertyName : String, 
    expression : String
)

参数

实现

IDTSPropertiesProvider. . :: . .SetExpression(String, String)

示例

The following code example hosts a SMO enumerator in the ForEachEnumeratorHost. Using the SetExpression method, the DelayValidation property is modified, then the expression is retrieved using the GetExpression method.

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;

namespace Microsoft.SqlServer.SSIS.Sample
{
    internal class EnumType
    {
        public const string SMOEnum = "Foreach SMO Enumerator";
    }
    class SSISProgram
    {
        static void Main(string[] args)
        {
            Application app = new Application();
            Package pkg = new Package();
            ForEachEnumeratorInfos infos = app.ForEachEnumeratorInfos;
            ForEachEnumeratorInfo info = null;

            foreach (ForEachEnumeratorInfo enumInfo in infos)
            {
                // Uncomment the next line of you want to see all enumerators.
                //Console.Write("Available enumerators: {0}\n", enumInfo.Name);
                if (enumInfo.Name == EnumType.SMOEnum)
                {
                    // Set the ForEachEnumeratorInfo variable
                    // to the SMO enumerator, and use it 
                    // later in the CreateNew method.
                    info = enumInfo;
                }
            }
            ForEachEnumeratorHost enumH = info.CreateNew();
            Console.WriteLine();
            // Show the description before it is modified.
            Console.WriteLine("DelayValidation:  {0}", enumH.DelayValidation);

            // Modify the Description using SetExpression.
            //String myExpression = "\"My Description for SMO enumerator\"";
            String myExpression = "true";
            enumH.SetExpression("DelayValidation", myExpression);

            DTSExecResult result = pkg.Validate(null, null, null, null);

            // Review the new value and expression.
            String newExpr = enumH.GetExpression("DelayValidation");
            Console.WriteLine("New DelayValidation: {0}", enumH.DelayValidation);
            Console.WriteLine("Expression:      {0}", newExpr);
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime

Friend Class EnumType
    Public Const SMOEnum As String = "Foreach SMO Enumerator"
End Class 'EnumType

Class SSISProgram
    
    Shared Sub Main(ByVal args() As String) 
        Dim app As New Application()
        Dim pkg As New Package()
        Dim infos As ForEachEnumeratorInfos = app.ForEachEnumeratorInfos
        Dim info As ForEachEnumeratorInfo = Nothing
        
        Dim enumInfo As ForEachEnumeratorInfo
        For Each enumInfo In  infos
            ' Uncomment the next line of you want to see all enumerators.
            'Console.Write("Available enumerators: {0}\n", enumInfo.Name);
            If enumInfo.Name = EnumType.SMOEnum Then
                ' Set the ForEachEnumeratorInfo variable
                ' to the SMO enumerator, and use it 
                ' later in the CreateNew method.
                info = enumInfo
            End If
        Next enumInfo
        Dim enumH As ForEachEnumeratorHost = info.CreateNew()
        Console.WriteLine()
        ' Show the description before it is modified.
        Console.WriteLine("DelayValidation:  {0}", enumH.DelayValidation)
        
        ' Modify the Description using SetExpression.
        'String myExpression = "\"My Description for SMO enumerator\"";
        Dim myExpression As String = "true"
        enumH.SetExpression("DelayValidation", myExpression)
        
        Dim result As DTSExecResult = pkg.Validate(Nothing, Nothing, Nothing, Nothing)
        
        ' Review the new value and expression.
        Dim newExpr As String = enumH.GetExpression("DelayValidation")
        Console.WriteLine("New DelayValidation: {0}", enumH.DelayValidation)
        Console.WriteLine("Expression:      {0}", newExpr)
    
    End Sub 'Main
End Class 'SSISProgram

Sample Output:

DelayValidation: False

New DelayValidation: False

Expression: true