语言

DtsEnumerator.MoveNext 方法

定义

将枚举器推进到集合的下一个元素。

public:
 virtual bool MoveNext();
public bool MoveNext();
abstract member MoveNext : unit -> bool
override this.MoveNext : unit -> bool
Public Function MoveNext () As Boolean

返回

如果枚举器成功进入下一个元素,则为真;如果枚举器已经过集合的末尾,则为假。

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,枚举器会被放置在集合的第一个元素之前,第一次调用 MoveNext 会将枚举器移动到集合的第一个元素上。

传递集合末尾后,后续调用将 MoveNext 返回 false ,直到 Reset 调用为止。

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 MoveNextReset 时会引发 InvalidOperationException 异常。

适用于