DtsProperty.SetExpression(Object, String) 方法

定义

命名空间:

Microsoft.SqlServer.Dts.Runtime

程序集:

Microsoft.SqlServer.ManagedDTS.dll

将指定的表达式分配给对象。 指定 null 以从属性中删除现有表达式。

public:
 void SetExpression(System::Object ^ o, System::String ^ expression);

public void SetExpression (object o, string expression);

member this.SetExpression : obj * string -> unit

Public Sub SetExpression (o As Object, expression As String)

参数

o

Object

向其分配表达式的对象的名称。

expression

String

表达式。

示例

是 ConnectionManager 一个继承自 IDTSPropertiesProvider 并实现该方法的 SetExpression 类。 下面的代码示例演示如何使用 SetExpression 方法。 表达式设置特定于连接管理器的属性的值。 与连接管理器唯一的属性包含在 Properties 集合中。

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

namespace ConnMgr_Properties_Collection  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            // The package is one of the SSIS Samples.  
            string mySample = @"C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx";  

            // Create an application and load the sample.  
            Application app = new Application();  
            Package pkg = app.LoadPackage(mySample, null);  
            Connections myConns = pkg.Connections;  

            // Get the Properties collection from the connection manager.  
            ConnectionManager myConnMgr = myConns[0];  
            DtsProperties connProperties = myConnMgr.Properties;  

            // View information about the RetainSameConnection property  
            // before setting it using the SetExpression method.  
            Boolean hasProperty = connProperties.Contains("RetainSameConnection");  
            Console.WriteLine("has RetainSameConnection? {0}", hasProperty);  
            Object myValue = myConnMgr.Properties["RetainSameConnection"].GetValue(myConnMgr);  
            String mySValue = myValue.ToString();  
            Console.WriteLine("value before is {0}", mySValue);String myTrueString = "true";  

            // Use SetExpression to set the value to true.  
            myConnMgr.Properties["RetainSameConnection"].SetExpression(myConnMgr, myTrueString);  

            // Validate the package to set the expression onto the property.  
            DTSExecResult valResult = pkg.Validate(myConns, null, null, null);  

            // Now that the value has been set, retrieve it.  
            myValue = myConnMgr.Properties["RetainSameConnection"].GetValue(myConnMgr);  
            mySValue = myValue.ToString();  
            Console.WriteLine("value after is {0}", mySValue);   
        }  
    }  
}  

Imports Microsoft.SqlServer.Dts.Runtime  

Namespace ConnMgr_Properties_Collection  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
        ' The package is one of the SSIS Samples.  
        Dim mySample As String = "C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx"  

        ' Create an application and load the sample.  
        Dim app As New Application()  
        Dim pkg As Package = app.LoadPackage(mySample, Nothing)  
        Dim myConns As Connections = pkg.Connections  

        ' Get the Properties collection from the connection manager.  
        Dim myConnMgr As ConnectionManager = myConns(0)  
        Dim connProperties As DtsProperties = myConnMgr.Properties  

        ' View information about the RetainSameConnection property  
        ' before setting it using the SetExpression method.  
        Dim hasProperty As [Boolean] = connProperties.Contains("RetainSameConnection")  
        Console.WriteLine("has RetainSameConnection? {0}", hasProperty)  
        Dim myValue As [Object] = myConnMgr.Properties("RetainSameConnection").GetValue(myConnMgr)  
        Dim mySValue As String = myValue.ToString()  
        Console.WriteLine("value before is {0}", mySValue)  
        Dim myTrueString As String = "true"  

        ' Use SetExpression to set the value to true.  
        myConnMgr.Properties("RetainSameConnection").SetExpression(myConnMgr, myTrueString)  

        ' Validate the package to set the expression onto the property.  
        Dim valResult As DTSExecResult = pkg.Validate(myConns, Nothing, Nothing, Nothing)  

        ' Now that the value has been set, retrieve it.  
        myValue = myConnMgr.Properties("RetainSameConnection").GetValue(myConnMgr)  
        mySValue = myValue.ToString()  
        Console.WriteLine("value after is {0}", mySValue)  
        End Sub  
    End Class  
End Namespace  

示例输出：

has RetainSameConnection? True

value before is False

value after is True

注解

所有容器和多个附加对象继承自 IDTSPropertiesProvider，后者是提供 GetExpression 和 SetExpression 方法的接口。