如何实现采用泛型参数的param数组(参数的可变数目)的函数

但是请注意,ParamArray参数必须由val声明,对数组的更改对调用代码没有影响。所以不能同时拥有可变数量的参数和ByRef语义。

public void DisposeObjects(params IDisposable[] args)
{
  foreach(IDisposable obj in args)
  {
     if(obj != null)
     {
        obj.Dispose();
     }
  }
}

以下是您的操作方法:

Public Sub DisposeObject(ByVal ParamArray disposableObjects() As IDisposable)
    For Each obj As IDisposable In disposableObjects
        If Not IsNothing(obj) Then obj.Dispose()
    Next
End Sub

using (var obj = new TypeImlementingIdisposable)
{
   //do stuff with the object here
}

在vb中:

Using obj As New TypeImlementingIdisposable
   ' do stuff with the object here
End Using

这样可以确保对象 总是 不管是否抛出异常,都会释放。

msdn

Public Sub DisposeObjects(Of T As IDisposable)(ByRef disposableObject As T)
    Dim disposable As IDisposable = CType(disposableObject, T)
    disposableObject = CType(Nothing, T)
    If (disposable IsNot Nothing) Then
        disposable.Dispose()
    End If
End Sub

用法:

Dim any as Foo=新Foo

处置对象(CType(any,Foo))