LogEntryInfoEnumerator.Current 属性
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
从集合获取当前的 LogEntryInfo 对象。
public:
property Microsoft::SqlServer::Dts::Runtime::LogEntryInfo ^ Current { Microsoft::SqlServer::Dts::Runtime::LogEntryInfo ^ get(); };
public Microsoft.SqlServer.Dts.Runtime.LogEntryInfo Current { get; }
member this.Current : Microsoft.SqlServer.Dts.Runtime.LogEntryInfo
Public ReadOnly Property Current As LogEntryInfo
属性值
获取集合中的当前 LogEntryInfo 元素。
示例
下面的代码示例创建一个枚举器,然后使用 CurrentMoveNext 和 Reset 方法在集合上导航。
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;
namespace LogEntryInfosTest
{
class Program
{
static void Main(string[] args)
{
// The package is one of the SSIS Samples.
string mySample = @"C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx";
// Create the Application, and load the sample.
Application app = new Application();
Package pkg = app.LoadPackage(mySample, null);
//Create the Enumerator.
LogEntryInfos leInfos = pkg.LogEntryInfos;
LogEntryInfoEnumerator myEnumerator = leInfos.GetEnumerator();
Console.WriteLine("The collection contains the following values:");
int i = 0;
while ((myEnumerator.MoveNext()) && (myEnumerator.Current != null))
Console.WriteLine("[{0}] {1}", i++, myEnumerator.Current);
Console.WriteLine();
}
}
}
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
Namespace LogEnTryInfosTest
Class Program
Shared Sub Main(ByVal args() As String)
' The package is one of the SSIS Samples.
Dim mySample As String = "C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx"
' Create the Application, and load the sample.
Dim app As Application = New Application()
Dim pkg As Package = app.LoadPackage(mySample,Nothing)
'Create the Enumerator.
Dim leInfos As LogEnTryInfos = pkg.LogEnTryInfos
Dim myEnumerator As LogEnTryInfoEnumerator = leInfos.GetEnumerator()
Console.WriteLine("The collection contains the following values:")
Dim i As Integer = 0
While (myEnumerator.MoveNext()) &&(myEnumerator.Current <> Nothing)
Console.WriteLine("[{0}] {1}",i = Console.WriteLine("[{0}] {1}",i + 1
End While
Console.WriteLine()
End Sub
End Class
End Namespace
示例输出:
集合包含以下值:
[0] Microsoft.SqlServer.Dts.Runtime.LogEntryInfo
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MoveNext
false
,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MoveNext
Reset
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
。 如果对集合的调用 MoveNext
和 Current调用之间修改, Current 则返回它设置为的元素,即使枚举器已失效。