Package.GetExpression 方法

Returns a value that contains the expression for the specified property. Null means no expression is assigned.

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 Function GetExpression ( _
    propertyName As String _
) As String
用法
Dim instance As Package 
Dim propertyName As String 
Dim returnValue As String 

returnValue = instance.GetExpression(propertyName)

public string GetExpression(
    string propertyName
)

public:
virtual String^ GetExpression(
    String^ propertyName
) sealed

abstract GetExpression : 
        propertyName:string -> string  
override GetExpression : 
        propertyName:string -> string

public final function GetExpression(
    propertyName : String
) : String

参数

• propertyName
  类型：System.String
  The name of the property whose expression you want to see.

返回值

类型：System.String
A value that contains the expression used to evaluate the property.

实现

IDTSPropertiesProvider.GetExpression(String)

注释

The propertyName can be any property available on the object.

示例

The following code example modifies the value of the DelayValidation property using SetExpression, then displays the new value using GetExpression.

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

namespace Microsoft.SqlServer.SSIS.Samples
{
    class Program
    {
        static void Main(string[] args)
        {
            Package pkg = new Package();
            // Set an expression on one of the properties.
            DtsProperties pkgProperties = pkg.Properties;

            // View information about the DelayValidation property 
            // before setting it with the SetExpression method.
            Object myValue = pkgProperties["DelayValidation"].GetValue(pkg);
            String mySValue = myValue.ToString();
            Console.WriteLine("value before is {0}", mySValue); 
            
            // Use SetExpression to set the value to true.
            String myTrueString = "true";
            pkgProperties["DelayValidation"].SetExpression(pkg, myTrueString);

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

            // Verify the new setting.
            myValue = pkgProperties["DelayValidation"].GetValue(pkg);
            mySValue = myValue.ToString();

            String myExpression = pkg.Properties["DelayValidation"].GetExpression(pkg);
            String mySExpression = myExpression.ToString();
            Console.WriteLine("The value and expression is {0}, {1}", mySValue, mySExpression);
        }
    }
}

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

Class Program
    Shared Sub Main(ByVal args() As String) 
        Dim pkg As New Package()
        ' Set an expression on one of the properties.
        Dim pkgProperties As DtsProperties = pkg.Properties
        
        ' View information about the DelayValidation property 
        ' before setting it with the SetExpression method.
        Dim myValue As [Object] = pkgProperties("DelayValidation").GetValue(pkg)
        Dim mySValue As String = myValue.ToString()
        Console.WriteLine("value before is {0}", mySValue)
        
        ' Use SetExpression to set the value to true.
        Dim myTrueString As String = "true"
        pkgProperties("DelayValidation").SetExpression(pkg, myTrueString)
        
        ' Validate the package to set the expression onto the property.
        Dim valResult As DTSExecResult = pkg.Validate(Nothing, Nothing, Nothing, Nothing)
        
        ' Verify the new setting.
        myValue = pkgProperties("DelayValidation").GetValue(pkg)
        mySValue = myValue.ToString()
        
        Dim myExpression As String = pkg.Properties("DelayValidation").GetExpression(pkg)
        Dim mySExpression As String = myExpression.ToString()
        Console.WriteLine("The value and expression is {0}, {1}", mySValue, mySExpression)
    End Sub
End Class

Sample Output:

value before is False

The value and expression is True, true

请参阅

参考

Package 类

Microsoft.SqlServer.Dts.Runtime 命名空间