一、禁止使用Alt+F4关闭窗口代码

　　Private Declare Function DeleteMenu Lib "user32" (ByVal hMenu As Long, ByVal nPosition As Long, ByVal wFlags As Long) As Long
　　Private Declare Function GetMenuItemCount Lib "user32" (ByVal hMenu As Long) As Long
Private Const MF_BYPOSITION = &H400&

　　Private Sub Form_Load()
　　Dim hwndMenu As Long
　　Dim c As Long
　　hwndMenu = GetSystemMenu(Me.hwnd, 0)

　　c = GetMenuItemCount(hwndMenu)

　　DeleteMenu hwndMenu, c - 1, MF_BYPOSITION

　　c = GetMenuItemCount(hwndMenu)
　　DeleteMenu hwndMenu, c - 1, MF_BYPOSITION
　　End Sub

　　二、限制软件的使用次数

　　①限制使用60次

　　Private Sub Form_Load()
　　Dim RemainDay As Long
　　RemainDay = GetSetting("MyApp", "set", "times", 0)
　　If RemainDay = 60 Then
  　　 MsgBox "试用次数已满，请购买正版"
  　　 Unload Me
　　End If
　　MsgBox "现在剩下：" & 60 - RemainDay & "的试用次数，请阁下珍惜！"
　　RemainDay = RemainDay + 1
　　SaveSetting "MyApp", "set", "times", RemainDay
　　End Sub

　　②限制使用60天

　　Private Sub Form_Load()
　　Dim RemainDay As Long
　　RemainDay = GetSetting("MyApp", "set", "day", 0)
　　If RemainDay = 60 Then
   　　 MsgBox "试用期已过，请购买正版"
   　　 Unload Me
　　End If
　　MsgBox "现在还剩下：" & 60 - RemainDay & "的试用天数，请阁下珍惜！"
　　if day(now)-remainday>0 then RemainDay = RemainDay + 1
　　SaveSetting "MyApp", "set", "times", RemainDay
　　End Sub