点击第一个按钮可以屏蔽最大（小）化按钮和关闭按钮，但是为什么点击第二个按钮不能恢复？

Private Declare Function GetSystemMenu Lib "user32" (ByVal hWnd As Long, ByVal bRevert As Long) As Long
Private Declare Function RemoveMenu Lib "user32" (ByVal hMenu As Long, ByVal nPosition As Long, ByVal wFlags As Long) As Long
Private Const MF_REMOVE = &H1000&
Private Const SC_CLOSE = &HF060
Private Const SC_MAXIMIZE = &HF030
Private Const SC_MINIMIZE = &HF020
public Sub command1_click()
  RemoveMenu GetSystemMenu(Me.hWnd, 0), SC_CLOSE, MF_REMOVE   '关闭按钮不可用
  RemoveMenu GetSystemMenu(Me.hWnd, 0), SC_MAXIMIZE, MF_REMOVE '最大化按钮不可用
  RemoveMenu GetSystemMenu(Me.hWnd, 0), SC_MINIMIZE, MF_REMOVE '最小化按钮不可用
End Sub
Public Sub Command2_click()
  RemoveMenu GetSystemMenu(Me.hWnd, 0), SC_CLOSE, SC_CLOSE  '关闭按钮不可用
  RemoveMenu GetSystemMenu(Me.hWnd, 0), SC_MAXIMIZE, SC_MAXIMIZE '最大化按钮不可用
  RemoveMenu GetSystemMenu(Me.hWnd, 0), SC_MINIMIZE, SC_MINIMIZE '最小化按钮不可用
End Sub

GetSystemMenu Me.hWnd, 1即可恢复

Public Sub Command2_Click()
GetSystemMenu Me.hWnd, 1
End Sub