DtsEventHandler.PrecedenceConstraints 属性

定义

命名空间:

Microsoft.SqlServer.Dts.Runtime

程序集:

Microsoft.SqlServer.ManagedDTS.dll

返回此容器中找到的可执行文件的优先约束的集合（如果有）。 此属性为只读。

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

一个 PrecedenceConstraints 集合。

实现

PrecedenceConstraints

示例

下面的代码示例为包中的事件创建一个DtsEventHandlerOnError。 此 DtsEventHandler 容器包含两个可执行文件，并在它们之间建立优先约束。 代码示例显示容器中的优先约束数。

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

namespace Microsoft.SqlServer.SSIS.Samples  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package pkg = new Package();  
            // Set up a DtsEventHandler for the OnError event of the package.  
            DtsEventHandler dtsEH = (DtsEventHandler)pkg.EventHandlers.Add("OnError");  

            // Show the name and type of the properties in DtsEventHandler  
            // using the Properties collection.  
            DtsProperties props = dtsEH.Properties;  
            String name;  
            TypeCode propType;  
            foreach (DtsProperty prop in props)  
            {  
                propType = prop.Type;  
                name = prop.Name;  
                Console.WriteLine("Name {0}, Type {1}", name, propType);  
            }  

            // When an OnError Event occurs, the Executables collection contains  
            // the items to run. For this example, there will be a SendMailtTask  
            // and a BulkInsertTask with a precedence constraint between them.  
            Executable dtsEH1 = dtsEH.Executables.Add("STOCK:SendMailTask");  
            TaskHost th = (TaskHost)dtsEH1;  
            SendMailTask smTask = (SendMailTask)th.InnerObject;  
            smTask.Subject = "Send Mail task";  

            // Add a second executable to the DtsEventHandler.  
            Executable dtsEH2 = dtsEH.Executables.Add("STOCK:BulkInsertTask");  
            TaskHost th2 = (TaskHost)dtsEH2;  

            // Add a precedence constraint between the two tasks.  
            PrecedenceConstraint pc = dtsEH.PrecedenceConstraints.Add(dtsEH1, dtsEH2);  
            pc.Value = DTSExecResult.Completion;  

            // Review the number of constraints in the DtsEventHandler collection.  
            PrecedenceConstraints pcDTSEH = dtsEH.PrecedenceConstraints;  
            Console.WriteLine("Number of precedence constraints in DtsEventHandler: {0}", dtsEH.PrecedenceConstraints.Count);  

            // Review the number of executables in the DtsEventHandler collection.  
            Console.WriteLine("Number of executables in DtsEventHandler: {0}", dtsEH.Executables.Count);  

            // Remove the first executable in the DtsEventHandler collection.  
            dtsEH.Executables.Remove(0);  
            Console.WriteLine("New number of exeutables in DtsEventHandler: {0}", dtsEH.Executables.Count);  
        }  
    }  
}  

Imports System  
Imports System.Collections.Generic  
Imports System.Text  
Imports Microsoft.SqlServer.Dts.Runtime  
Imports Microsoft.SqlServer.Dts.Tasks.SendMailTask  
Imports Microsoft.SqlServer.Dts.Tasks.BulkInsertTask  

Namespace Microsoft.SqlServer.SSIS.Samples  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim pkg As Package =  New Package()   
            ' Set up a DtsEventHandler for the OnError event of the package.  
            Dim dtsEH As DtsEventHandler = CType(pkg.EventHandlers.Add("OnError"), DtsEventHandler)  

            ' Show the name and type of the properties in DtsEventHandler  
            ' using the Properties collection.  
            Dim props As DtsProperties =  dtsEH.Properties   
            Dim name As String  
            Dim propType As TypeCode  
            Dim prop As DtsProperty  
            For Each prop In props  
                propType = prop.Type  
                name = prop.Name  
                Console.WriteLine("Name {0}, Type {1}", name, propType)  
            Next  

            ' When an OnError Event occurs, the Executables collection contains  
            ' the items to run. For this example, there will be a SendMailtTask  
            ' and a BulkInsertTask with a precedence constraint between them.  
            Dim dtsEH1 As Executable =  dtsEH.Executables.Add("STOCK:SendMailTask")   
            Dim th As TaskHost = CType(dtsEH1, TaskHost)  
            Dim smTask As SendMailTask = CType(th.InnerObject, SendMailTask)  
            smTask.Subject = "Send Mail task"  

            ' Add a second executable to the DtsEventHandler.  
            Dim dtsEH2 As Executable =  dtsEH.Executables.Add("STOCK:BulkInsertTask")   
            Dim th2 As TaskHost = CType(dtsEH2, TaskHost)  

            ' Add a precedence constraint between the two tasks.  
            Dim pc As PrecedenceConstraint =  dtsEH.PrecedenceConstraints.Add(dtsEH1,dtsEH2)   
            pc.Value = DTSExecResult.Completion  

            ' Review the number of constraints in the DtsEventHandler collection.  
            Dim pcDTSEH As PrecedenceConstraints =  dtsEH.PrecedenceConstraints   
            Console.WriteLine("Number of precedence constraints in DtsEventHandler: {0}", dtsEH.PrecedenceConstraints.Count)  

            ' Review the number of executables in the DtsEventHandler collection.  
            Console.WriteLine("Number of executables in DtsEventHandler: {0}", dtsEH.Executables.Count)  

            ' Remove the first executable in the DtsEventHandler collection.  
            dtsEH.Executables.Remove(0)  
            Console.WriteLine("New number of exeutables in DtsEventHandler: {0}", dtsEH.Executables.Count)  
        End Sub  
    End Class  
End Namespace  

示例输出：

名称创建名称，类型字符串

Name DelayValidation，类型布尔值

名称说明，类型字符串

名称禁用，键入布尔值

名称可执行文件，类型对象

名称 ExecutionDuration，类型 Int32

Name ExecutionResult，Type 对象

名称 ExecutionStatus，Type 对象

名称变量，类型对象

DtsEventHandler 中的优先约束数：1

DtsEventHandler 中的可执行文件数：2

DtsEventHandler 中的新执行项数：1

注解

集合 PrecedenceConstraints 是对象的集合 PrecedenceConstraint 。