DtsEnumerator.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。
获取集合中的当前元素。
public:
property System::Object ^ Current { System::Object ^ get(); };public object Current { get; }member this.Current : objPublic ReadOnly Property Current As Object属性值
集合中的当前元素。
实现
示例
以下代码示例是将任务添加到一个包中，然后运行该包。 警告集合通过创建一个WarningEnumerator继承自该DtsEnumerator类的 ，并展示每个警告描述及其CurrentMoveNext在集合中审查警告的方法。
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;
using Microsoft.SqlServer.Dts.Tasks.ExecuteSQLTask;
namespace Microsoft.SqlServer.SSIS.Samples
{
class Program
{
static void Main(string[] args)
{
Package package = new Package();
Console.WriteLine("Package warnings count before running: {0}", package.Warnings.Count);
TaskHost taskH2 = (TaskHost)package.Executables.Add("STOCK:SendMailTask");
taskH2.FailPackageOnFailure = false;
taskH2.FailParentOnFailure = false;
Console.WriteLine("SendMailTask: {0}", taskH2.ID);
// Test that warnings were successfully added to the collection.
package.MaximumErrorCount = 100;
package.FailPackageOnFailure = false;
package.FailParentOnFailure = false;
package.DelayValidation = true;
package.Execute();
Console.WriteLine("Package warnings count after running the package: {0}", package.Warnings.Count);
// Create the enumerator.
WarningEnumerator myEnumerator = package.Warnings.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.Description);
}
}
}
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
Imports Microsoft.SqlServer.Dts.Tasks.ExecuteSQLTask
Namespace Microsoft.SqlServer.SSIS.Samples
Class Program
Shared Sub Main(ByVal args() As String)
Dim package As Package = New Package()
Console.WriteLine("Package warnings count before running: {0}", package.Warnings.Count)
Dim taskH2 As TaskHost = CType(package.Executables.Add("STOCK:SendMailTask"), TaskHost)
taskH2.FailPackageOnFailure = False
taskH2.FailParentOnFailure = False
Console.WriteLine("SendMailTask: {0}", taskH2.ID)
' Test that warnings were successfully added to the collection.
package.MaximumErrorCount = 100
package.FailPackageOnFailure = False
package.FailParentOnFailure = False
package.DelayValidation = True
package.Execute()
Console.WriteLine("Package warnings count after running the package: {0}", package.Warnings.Count)
' Create the enumerator.
Dim myEnumerator As WarningEnumerator = package.Warnings.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
End Sub
End Class
End Namespace
示例输出：
包裹警告在运行前计数：0
SendMailTask： {34CAEFF9-64BF-401D-B646-C88B705DB971}
包裹警告在运行包后计入：2
该集合包含以下数值：
[0] 发件人行中的地址未正确生成。 缺少@或无效。
[1] 主语为空
注解
在创建枚举器或调用 Reset 方法后，必须先调用该 MoveNext 方法，将枚举器推进到集合的第一个元素，然后才能读取 的 Current值;否则， Current 是未定义的。
Current 如果最后一次调用 MoveNext 返回 false，则也会引发异常，这表示集合的末尾。
Current不会移动枚举器的位置，因此连续调用Current返回同一对象，直到被调用或MoveNextReset。
只要集合保持不变，枚举器就保持有效。 如果对集合进行了更改（例如添加、修改或删除元素），枚举器将不可恢复地失效，并且下次调用 MoveNext 或 Reset 时会引发 InvalidOperationException 异常。 如果集合在两MoveNext者之间Current进行了修改，Current将返回它设置为的元素，即使枚举器已失效。