ConnectionManager.SetExpression(String, 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属性。 指定 null 以从属性中删除现有表达式。

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

public void SetExpression (string propertyName, string expression);

abstract member SetExpression : string * string -> unit
override this.SetExpression : string * string -> unit

Public Sub SetExpression (propertyName As String, expression As String)

参数

propertyName

String

向其分配表达式的属性的名称。

expression

String

表达式。

实现

SetExpression(String, String)

示例

下面的代码示例演示如何使用表达式设置特定于连接管理器的属性的值。 连接管理器特有的属性包含在集合中 Properties 。

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 System  
Imports System.Collections.Generic  
Imports System.Text  
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

值为 False 之前的值

值为 True

注解

连接 propertyName 管理器对象的连接字符串、说明、名称或保护级别。 对于连接管理器，这些属性当前是唯一支持表达式的属性。 除了这些常见的连接管理器属性外，每个连接类型都具有唯一的属性。 这些属性由 Properties 集合列出。 可以使用 SetExpression 该方法提供要设置为 String 参数的属性的名称。 如果要使用 Properties 集合设置与连接唯一的属性，则知道此属性集合继承自 DtsProperty该属性可能很有用。 请注意， SetExpression 继承自 DtsProperty 采用的第一个 Object 参数，而不是一个 String参数。