Package.PrecedenceConstraints 属性

定义

命名空间:

Microsoft.SqlServer.Dts.Runtime

程序集:

Microsoft.SqlServer.ManagedDTS.dll

获取 PrecedenceConstraint 对象的集合。 此字段为只读。

public:
 property Microsoft::SqlServer::Dts::Runtime::PrecedenceConstraints ^ PrecedenceConstraints { Microsoft::SqlServer::Dts::Runtime::PrecedenceConstraints ^ get(); };

public Microsoft.SqlServer.Dts.Runtime.PrecedenceConstraints PrecedenceConstraints { get; }

member this.PrecedenceConstraints : Microsoft.SqlServer.Dts.Runtime.PrecedenceConstraints

Public ReadOnly Property PrecedenceConstraints As PrecedenceConstraints

属性值

PrecedenceConstraints

PrecedenceConstraint 对象的集合。

实现

PrecedenceConstraints

示例

下面的代码示例将两个任务添加到包中，并在它们之间放置优先约束。 然后，它会计算包集合中的约束数。

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

namespace DataFlow_Conceptual  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package p = new Package();  
            // Add a File System task.  
            Executable eFileTask1 = p.Executables.Add("STOCK:FileSystemTask");  
            TaskHost thFileHost1 = eFileTask1 as TaskHost;  

            // Add a second File System task.  
            Executable eFileTask2 = p.Executables.Add("STOCK:FileSystemTask");  
            TaskHost thFileHost2 = eFileTask2 as TaskHost;  

            // Put a precedence constraint between the tasks.  
            // Set the constraint to be that thFileTask2 cannot run  
            // unless thFileTask1 completes.  
            PrecedenceConstraint pcFileTasks = p.PrecedenceConstraints.Add((Executable)thFileHost1, (Executable) thFileHost2);  
            pcFileTasks.Value = DTSExecResult.Completion;  

            // Return and show the count of precedence constraints in the package.  
            PrecedenceConstraints pCons = p.PrecedenceConstraints;  
            Console.WriteLine("Precedence constraints in package = {0}",  pCons.Count);  

        }  
    }  
}  

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

Namespace Package_API  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim app As Application =  New Application()   
            Dim pkg As Package =  New Package()   
            pkg = app.LoadPackage("C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx", Nothing)  

            ' Show the package type  
            Console.WriteLine("The package type is {0}", pkg.PackageType)  
        End Sub  
    End Class  
End Namespace  

示例输出：

Precedence constraints in package = 1

注解

返回对象集合 PrecedenceConstraint ，这些对象包含有关执行步骤之前必须发生的条件的信息。 有关优先约束的详细信息，请参阅 优先约束。