您可以使用If operator重载的版本仅接受两个参数：

Dim myVar? As Integer = Nothing
Console.WriteLine(If(myVar,7))

更多信息可以在VB.NET团队的博客文章中找到here。

(是的，这是一个运算符，即使它看起来像一个函数，它将编译到与C#中的“正确”空聚合运算符相同的IL)。

例

Dim b As Boolean?
Console.WriteLine("{0}.",If(b,"this is expected when b is nothing"))
'output: this is expected when b is nothing.

b = False
Console.WriteLine("{0}.","this is unexpected when b is false"))
'output: False.

b = True
Console.WriteLine("{0}.","this is unexpected when b is true"))
'output: True.