TaskHost.GetExpression(String) Method


Returns the expression for the specified property. Null means no expression is assigned.

 virtual System::String ^ GetExpression(System::String ^ propertyName);
public string GetExpression (string propertyName);
abstract member GetExpression : string -> string
override this.GetExpression : string -> string
Public Function GetExpression (propertyName As String) As String



The name of the property whose expression you want to see.


A String that contains the expression used to evaluate the property.



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


The propertyName can be any property available on the object.

Applies to