PrecedenceConstraints.Item Özelliği
Döndürür bir PrecedenceConstraint gelen nesne koleksiyon.
Ad Alanı: Microsoft.SqlServer.Dts.Runtime
Derleme: Microsoft.SqlServer.ManagedDTS (Microsoft.SqlServer.ManagedDTS içinde.dll)
Sözdizimi
'Bildirim
Public ReadOnly Default Property Item ( _
index As Object _
) As PrecedenceConstraint
Get
'Kullanım
Dim instance As PrecedenceConstraints
Dim index As Object
Dim value As PrecedenceConstraint
value = instance(index)
public PrecedenceConstraint this[
Object index
] { get; }
public:
property PrecedenceConstraint^ default[Object^ index] {
PrecedenceConstraint^ get (Object^ index);
}
member Item : PrecedenceConstraint
JScript, dizinli özelliklerin kullanılmasını destekler, ancak yenilerinin bildirilmesini desteklemez.
Parametreler
- index
Tür: System.Object
Adı, kimlik veya dizini bulmak için koleksiyon.
Özellik Değeri
Açıklamalar
Çağrı Contains yöntem döndürür doğru, belirtilen öğe erişebilirsiniz koleksiyon sözdizimini kullanarak PrecedenceConstraints[index].Ancak, Contains yöntem döndürür yanlış, bu özellik bir istisna atar.C# ile dizinleyici için bu özellik olan PrecedenceConstraints WalkTree
Örnekler
Aşağıdaki kod örneği, iki öncelik kısıtlamaları oluşturur.Daha sonra kullanır Contains belirli bir kısıtlama varlığını doğrulamak için kısıtlamalar önce ve sonra kullanımını sayar Remove yöntem ve nasıl kullanılacağını gösterir GetEnumerator üzerinden yinelemek yapmak için koleksiyon, kullanma Item sözdizimi pConsts[i].ID dönmek için ID kısıtlama.
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;
using Microsoft.SqlServer.Dts.Tasks.FileSystemTask;
using Microsoft.SqlServer.Dts.Tasks.BulkInsertTask;
namespace PrecedenceConst
{
class Program
{
static void Main(string[] args)
{
Package pkg = new Package();
// Add a File System task.
Executable eFileTask1 = pkg.Executables.Add("STOCK:FileSystemTask");
TaskHost thFileTask1 = eFileTask1 as TaskHost;
// Add a second File System task.
Executable eFileTask2 = pkg.Executables.Add("STOCK:FileSystemTask");
TaskHost thFileTask2 = eFileTask2 as TaskHost;
// Add a Bulk Insert task.
Executable eBulkInsert = pkg.Executables.Add("STOCK:BulkInsertTask");
TaskHost thBulkInsert = eBulkInsert as TaskHost;
// Add a precedence constraint between eFileTask1 and eFileTask2.
// Set the constraint to be that eFileTask2 cannot run
// until eFileTask1 completes.
PrecedenceConstraint pcFileTasks = pkg.PrecedenceConstraints.Add(eFileTask1, eFileTask2);
pcFileTasks.Name = "constraint between File System Tasks";
// Add another precedence constraint. Add it between eFileTask2 and BulkInsert.
// Again, set the constraint to be that BulkInsert cannot run
// until eFileTask2 completes.
PrecedenceConstraint pcFiletoBulk = pkg.PrecedenceConstraints.Add(eFileTask2, eBulkInsert);
pcFileTasks.Name = "constraint between File System and Bulk Insert Tasks";
// Obtain the precedence constraint collection.
PrecedenceConstraints pConsts = pkg.PrecedenceConstraints;
Boolean containsConstraint = pkg.PrecedenceConstraints.Contains("constraint between File System and Bulk Insert Tasks");
Console.WriteLine("Contains the constraint between File System and Bulk Insert Tasks? {0}", containsConstraint);
// Create the enumerator.
PrecedenceConstraintEnumerator myEnumerator = pConsts.GetEnumerator();
// Iterate over the collection, and remove the Bulk Insert task.
int i = 0;
while ((myEnumerator.MoveNext()) && (myEnumerator.Current != null))
{
Console.WriteLine("ID {0}", pConsts[i].ID);
}
Console.WriteLine("Number of constraints {0}", pConsts.Count);
// Remove the second contstraint.
pConsts.Remove(1);
// Verify that one has been removed.
Console.WriteLine("Number of constraints {0}", pConsts.Count);
Console.WriteLine();
}
}
}
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
Imports Microsoft.SqlServer.Dts.Tasks.FileSystemTask
Imports Microsoft.SqlServer.Dts.Tasks.BulkInsertTask
Namespace PrecedenceConst
Class Program
Shared Sub Main(ByVal args() As String)
Dim pkg As Package = New Package()
' Add a File System task.
Dim eFileTask1 As Executable = pkg.Executables.Add("STOCK:FileSystemTask")
Dim thFileTask1 As TaskHost = eFileTask1 as TaskHost
' Add a second File System task.
Dim eFileTask2 As Executable = pkg.Executables.Add("STOCK:FileSystemTask")
Dim thFileTask2 As TaskHost = eFileTask2 as TaskHost
' Add a Bulk Insert task.
Dim eBulkInsert As Executable = pkg.Executables.Add("STOCK:BulkInsertTask")
Dim thBulkInsert As TaskHost = eBulkInsert as TaskHost
' Add a precedence constraint between eFileTask1 and eFileTask2.
' Set the constraint to be that eFileTask2 cannot run
' until eFileTask1 completes.
Dim pcFileTasks As PrecedenceConstraint = pkg.PrecedenceConstraints.Add(eFileTask1,eFileTask2)
pcFileTasks.Name = "constraint between File System Tasks"
' Add another precedence constraint. Add it between eFileTask2 and BulkInsert.
' Again, set the constraint to be that BulkInsert cannot run
' until eFileTask2 completes.
Dim pcFiletoBulk As PrecedenceConstraint = pkg.PrecedenceConstraints.Add(eFileTask2,eBulkInsert)
pcFileTasks.Name = "constraint between File System and Bulk Insert Tasks"
' Obtain the precedence constraint collection.
Dim pConsts As PrecedenceConstraints = pkg.PrecedenceConstraints
Dim containsConstraint As Boolean = pkg.PrecedenceConstraints.Contains("constraint between File System and Bulk Insert Tasks")
Console.WriteLine("Contains the constraint between File System and Bulk Insert Tasks? {0}", containsConstraint)
' Create the enumerator.
Dim myEnumerator As PrecedenceConstraintEnumerator = pConsts.GetEnumerator()
' Iterate over the collection, and remove the Bulk Insert task.
Dim i As Integer = 0
While (myEnumerator.MoveNext()) &&(myEnumerator.Current <> Nothing)
Console.WriteLine("ID {0}", pConsts(i).ID)
End While
Console.WriteLine("Number of constraints {0}", pConsts.Count)
' Remove the second contstraint.
pConsts.Remove(1)
' Verify that one has been removed.
Console.WriteLine("Number of constraints {0}", pConsts.Count)
Console.WriteLine()
End Sub
End Class
End Namespace
Örnek Çıktı:
Kısıtlama Ekle toplu görev dosya sistemi arasındaki içerir?True
ID: BA42AF32-3AC1-4CB6-85A2-289760ADBFA4
ID: BA42AF32-3AC1-4CB6-85A2-289760ADBFA4
2 Kısıtlamaları sayısı
1 Kısıtlamaları sayısı