GetExpression 方法

Returns 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 TaskHost
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 String 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 shows how to use the SetExpression and GetExpression methods of the TaskHost. For this code example, the hosted task is the BulkInsertTask.

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


namespace Microsoft.SqlServer.SSIS.Sample
{
    class Program
        {
        static void Main(string[] args)
        {
            Package pkg = new Package();
            TaskHost th = (TaskHost)pkg.Executables.Add("STOCK:BulkInsertTask");

            // View information about the CheckConstraints property
            // before setting it using the SetExpression method.
            Boolean checkConstraint = (Boolean)th.Properties["CheckConstraints"].GetValue(th);
            Console.WriteLine("Original value of CheckConstraints: {0}", checkConstraint);

            // Use SetExpression to set the value to true.
            String myTrueString = "true";
            th.Properties["CheckConstraints"].SetExpression(th, myTrueString);

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

            // Retrieve the new value and the expression.
            checkConstraint = (Boolean)th.Properties["CheckConstraints"].GetValue(th);
            String myExpression = th.Properties["CheckConstraints"].GetExpression(th);
            Console.WriteLine("New value of CheckConstraints: {0}", checkConstraint);
            Console.WriteLine("Expression for CheckConstraints: {0}", myExpression);
        }
    }
}

Sample Output:

Original value of CheckConstraints: False

New value of CheckConstraints: True

Expression for CheckConstraints: true

请参阅

参考

TaskHost 类

Microsoft.SqlServer.Dts.Runtime 命名空间