调用 New 后，“对象引用未设置到对象的实例”

Question

Public Class Form1
    Dim Form2 As Form2
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        With Me.Form2
            Me.Form2 = New Form2("Some name")
            .TopLevel = False
        End With
    End Sub
End Class

Public Class Form2
    Public Property AAAName As String
    Sub New(NameInput As String)
        Me.AAAName = NameInput
        InitializeComponent()
    End Sub
    Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub
End Class

当我运行代码（从 Form1 开始）时，出现错误：对象引用未设置到对象的实例

Answer 1

尝试在 With 块之前初始化 Form2，如下所示：

Public Class Form1
Dim Form2 As Form2

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Me.Form2 = New Form2("Form name")
    
    With Me.Form2
        .TopLevel = False
    End With

    Me.Controls.Add(Form2)
    Form2.Show()
  End Sub
End Class



Public Class Form2
Public Property AAAName As String

Sub New(NameInput As String)
    Me.AAAName = NameInput
    InitializeComponent()
End Sub

Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load

  End Sub
End Class