TaskHost.GetExpression(String) 方法

定义

命名空间:

Microsoft.SqlServer.Dts.Runtime

程序集:

Microsoft.SqlServer.ManagedDTS.dll

返回指定属性的表达式。 Null 表示未分配任何表达式。

public:
 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

参数

propertyName

String

要查看其表达式的属性的名称。

返回

String

包含用于计算属性的表达式的字符串。

实现

GetExpression(String)

示例

下面的代码示例演示如何使用 SetExpression .GetExpressionTaskHost 对于此代码示例，托管的任务是 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);  
        }  
    }  
}  

示例输出：

CheckConstraints 的原始值：False

CheckConstraints 的新值：True

CheckConstraints 的表达式： true

注解

可以是 propertyName 对象上可用的任何属性。