用'Using'调用或直接调用'DIspose'时出现奇怪的'Dispose'错误

Question

我有这个有效的代码：

Option Strict On
Imports System
Imports System.IO
Imports System.ServiceModel
Imports System.ServiceModel.Description
...
 Private Property Channel As IWSOServiceContract

 Public Sub SomeMethod(ByVal url As String)
    Using ChlFactory As ChannelFactory(Of IWSOServiceContract) = New ChannelFactory(Of IWSOServiceContract)(New WebHttpBinding(), url)
       ChlFactory.Endpoint.Behaviors.Add(New WebHttpBehavior())
       Channel = ChlFactory.CreateChannel()
    End Using
 End Sub
...

但是当我将其重构为：

Option Strict On
Imports System
Imports System.IO
Imports System.ServiceModel
Imports System.ServiceModel.Description
...
Private Property ChlFactory As ChannelFactory(Of IWSOServiceContract)
Private Property Channel As IWSOServiceContract

Public Sub SomeMethod(ByVal url As String)
    ChlFactory = New ChannelFactory(Of IWSOServiceContract)(New WebHttpBinding(), url)
    ChlFactory.Endpoint.Behaviors.Add(New WebHttpBehavior())
    Channel = ChlFactory.CreateChannel()
    ChlFactory.Dispose()   '<-- ERROR HERE BUT HOW DID USING WORK BEFORE?
End Sub 
...

完全不知所措，没有任何解释为什么第二种方法有错误"Dispose is not a member of ChannelFactory"而第一种方法没有错误？

Answer 1

那是因为 ChannelFactory implements IDisposable.Dispose explicitly。您必须将其转换为 IDisposable 才能调用 Dispose.

Using 语句足够聪明，可以为您进行转换。

用'Using'调用或直接调用'DIspose'时出现奇怪的'Dispose'错误

Strange 'Dispose' Error when calling with 'Using' or directly calling 'DIspose'

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