ConfigurationEnumerator.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。
从集合中获取当前 Configuration 对象。
public:
property Microsoft::SqlServer::Dts::Runtime::Configuration ^ Current { Microsoft::SqlServer::Dts::Runtime::Configuration ^ get(); };
public Microsoft.SqlServer.Dts.Runtime.Configuration Current { get; }
member this.Current : Microsoft.SqlServer.Dts.Runtime.Configuration
Public ReadOnly Property Current As Configuration
属性值
集合中的当前元素。
示例
以下代码示例创建 , ConfigurationEnumerator然后遍历集合,显示配置名称。
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;
namespace Configurations_API
{
class Program
{
static void Main(string[] args)
{
Package p = new Package();
Configuration conf1 = p.Configurations.Add();
conf1.ConfigurationString = "Conf1 Configuration String";
conf1.ConfigurationType = DTSConfigurationType.EnvVariable;
conf1.Description = "Some description for Conf1 configuration";
conf1.Name = "Conf1";
conf1.PackagePath = "A Variable Name in configuration Conf1";
Configuration conf2 = p.Configurations.Add();
conf2.ConfigurationString = "Conf2 Configuration String";
conf2.ConfigurationType = DTSConfigurationType.ConfigFile;
conf2.Description = "Some description for Conf2 configuration";
conf2.Name = "Conf2";
conf2.PackagePath = "A Variable Name in configuration Conf2";
Configuration conf3 = p.Configurations.Add();
conf3.ConfigurationString = "Conf3 Configuration String2";
conf3.ConfigurationType = DTSConfigurationType.RegEntry;
conf3.Description = "Conf3 description for Conf3 configuration2";
conf3.Name = "Conf3";
conf3.PackagePath = "A Variable Name in configuration Conf3";
Configurations pkgConfigs = p.Configurations;
ConfigurationEnumerator myEnumerator = pkgConfigs.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.Name);
}
}
}
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
Namespace Configurations_API
Class Program
Shared Sub Main(ByVal args() As String)
Dim p As Package = New Package()
Dim conf1 As Configuration = p.Configurations.Add()
conf1.ConfigurationString = "Conf1 Configuration String"
conf1.ConfigurationType = DTSConfigurationType.EnvVariable
conf1.Description = "Some description for Conf1 configuration"
conf1.Name = "Conf1"
conf1.PackagePath = "A Variable Name in configuration Conf1"
Dim conf2 As Configuration = p.Configurations.Add()
conf2.ConfigurationString = "Conf2 Configuration String"
conf2.ConfigurationType = DTSConfigurationType.ConfigFile
conf2.Description = "Some description for Conf2 configuration"
conf2.Name = "Conf2"
conf2.PackagePath = "A Variable Name in configuration Conf2"
Dim conf3 As Configuration = p.Configurations.Add()
conf3.ConfigurationString = "Conf3 Configuration String2"
conf3.ConfigurationType = DTSConfigurationType.RegEnTry
conf3.Description = "Conf3 description for Conf3 configuration2"
conf3.Name = "Conf3"
conf3.PackagePath = "A Variable Name in configuration Conf3"
Dim pkgConfigs As Configurations = p.Configurations
Dim myEnumerator As ConfigurationEnumerator = pkgConfigs.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:
该集合包含以下数值:
[0] conf1
[1] 秘密2
[2] Conf3
注解
在创建枚举器或调用该方法后 Reset ,必须先调用该 MoveNext 方法,将枚举器推进到集合的第一个元素,然后才能读取属性的 Current 值;否则,为 Current 未定义并抛出异常。
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,并且连续调用返回同一对象,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,比如添加、修改或删除元素,枚举器将失效并无法恢复;因此,下一次调用 MoveNext 或 Reset 会抛出 InvalidOperationException。 然而,如果集合在调用和MoveNextCurrent之间被修改,Current即使枚举器已被失效,集合返回了它所设定的元素。