vb.net Nothing对象编程实例，经典代码和每行后面备注

好的，下面是一个经典的VB.NET实例，演示如何使用Nothing对象：

Dim myObject As Object = Nothing '定义一个对象变量并赋值为Nothing
Console.WriteLine("myObject is " & If(myObject Is Nothing, "Nothing", "something")) '判断对象是否为Nothing并输出结果

If myObject Is Nothing Then '判断对象是否为Nothing
    Console.WriteLine("myObject is Nothing, creating new instance...") '输出提示信息
    myObject = New Object() '创建一个新的对象实例
    Console.WriteLine("myObject is now " & If(myObject Is Nothing, "Nothing", "something")) '再次判断对象是否为Nothing并输出结果
End If

Console.ReadLine() '等待用户输入

注释：

- `Dim myObject As Object = Nothing`：定义一个对象变量并赋值为Nothing。
- `Console.WriteLine("myObject is " & If(myObject Is Nothing, "Nothing", "something"))`：判断对象是否为Nothing并输出结果。
- `If myObject Is Nothing Then`：判断对象是否为Nothing。
- `Console.WriteLine("myObject is Nothing, creating new instance...")`：输出提示信息。
- `myObject = New Object()`：创建一个新的对象实例。
- `Console.WriteLine("myObject is now " & If(myObject Is Nothing, "Nothing", "something"))`：再次判断对象是否为Nothing并输出结果。
- `Console.ReadLine()`：等待用户输入。