PropertyEnumerator.Current 属性

定义

命名空间:

Microsoft.SqlServer.Dts.Runtime

程序集:

Microsoft.SqlServer.ManagedDTS.dll

返回集合中的当前 DtsProperty 元素。

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

public Microsoft.SqlServer.Dts.Runtime.DtsProperty Current { get; }

member this.Current : Microsoft.SqlServer.Dts.Runtime.DtsProperty

Public ReadOnly Property Current As DtsProperty

属性值

DtsProperty

DtsProperty 对象。

示例

下面的代码示例创建一个 PropertyEnumerator，然后显示如何使用 MoveNext 和 Current 方法在集合上移动。

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

namespace DtsProperties_API  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package pkg = new Package();  

            // Get the Properties collection from the package.  
            // This shows the default properties set on new packages.  
            DtsProperties pkgProperties = pkg.Properties;  

           // Create the enumerator.  
            PropertyEnumerator myEnumerator = pkgProperties.GetEnumerator();  

            // Show the use of the Contains method.  
            Boolean containsCertObj = pkgProperties.Contains("CertificateObject");  
            Console.WriteLine("Contains CertificateObject? {0}", containsCertObj);  

            // Show the use of the item[x] syntax.  
            String aName = pkgProperties[5].Name;  
            Console.WriteLine("Property 5 is {0}", aName);  

            // Show the use of the MoveNext and Current methods.  
            int i = 0;  
            while ((myEnumerator.MoveNext()) && (myEnumerator.Current != null))  
            {  
                Console.WriteLine("[{0}] {1}", i++, myEnumerator.Current.Name);  
            }  
        }  
    }  
}  

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

Namespace DtsProperties_API  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim pkg As Package =  New Package()   

            ' Get the Properties collection from the package.  
            ' This shows the default properties set on new packages.  
            Dim pkgProperties As DtsProperties =  pkg.Properties   

           ' Create the enumerator.  
            Dim myEnumerator As PropertyEnumerator =  pkgProperties.GetEnumerator()   

            ' Show the use of the Contains method.  
            Dim containsCertObj As Boolean =  pkgProperties.Contains("CertificateObject")   
            Console.WriteLine("Contains CertificateObject? {0}", containsCertObj)  

            ' Show the use of the item[x] syntax.  
            Dim aName As String =  pkgProperties(5).Name   
            Console.WriteLine("Property 5 is {0}", aName)  

            ' Show the use of the MoveNext and Current methods.  
            Dim i As Integer =  0   
            While (myEnumerator.MoveNext()) &&(myEnumerator.Current <> Nothing)  
                Console.WriteLine("[{0}] {1}",i = Console.WriteLine("[{0}] {1}",i + 1  
            End While  
        End Sub  
    End Class  
End Namespace  

示例输出：

包含 CertificateObject？ True

属性 5 是配置

[0] CertificateContext

[1] CertificateObject

[2] CheckpointFileName

[3] CheckpointUsage

[4] CheckSignatureOnLoad

[5] 配置

[6] 连接

[7] CreationDate

[8] CreationName

[9] CreatorComputerName

[10] CreatorName

[11] DelayValidation

. . .

[63] VersionGUID

[64] VersionMajor

[65] VersionMinor

[66] 警告

注解

创建枚举器或调用 Reset 方法后， MoveNext 必须调用该方法才能将枚举器推进到集合的第一个元素，然后枚举器才能读取属性的值 Current ;否则， Current 未定义并引发异常。

Current如果最后一次调用返回MoveNextfalse，则也会引发异常，该调用指示集合的末尾。

Current不会移动枚举器的位置，并且连续调用以Current返回相同的对象，直到调用或MoveNextReset调用。

只要集合保持不变，枚举器就仍有效。 如果对集合进行了更改（例如添加、修改或删除元素），则枚举器将失效并变为不可恢复;因此，下一次调用 MoveNext 或 Reset 引发一个 InvalidOperationException。 但是，如果在调用 MoveNext 和 Current调用之间修改集合， Current 则返回它设置为的元素，即使枚举器已失效也是如此。