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vb.net中阻止关闭,vb 关闭窗体

vb.net中 如何将窗体上的关闭按钮禁用 也就是变灰啊?

FormBorderStyle选为None,没有标题栏

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form 的 controlbox 属性为false

vb.net2008拦截关机或注销消息

在SystemEvents类中 可以 用户试图注销或关闭系统时发生。 (当用户试图注销或关闭系统时发生。当用户试图注销或关闭系统时发生。) 这个 事件处理函数中 可以找到如下方法

Private Shared WM_QUERYENDSESSION As Integer = H11

Private Shared systemShutdown As Boolean = False

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)

If m.Msg = WM_QUERYENDSESSION Then

'MessageBox.Show("queryendsession: this is a logoff, shutdown, or reboot")

systemShutdown = True

End If

' If this is WM_QUERYENDSESSION, the closing event should be raised in the base WndProc.

MyBase.WndProc(m)

End Sub 'WndProc

Private Sub Form1_Closing(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing

If (systemShutdown) Then

' Reset the variable because the user might cancel the shutdown.

systemShutdown = False

If (System.Windows.Forms.DialogResult.Yes = _

MessageBox.Show("My application", "Do you want to save your work before logging off?", MessageBoxButtons.YesNo)) Then

e.Cancel = True

Else

e.Cancel = False

End If

End If

End Sub

vb.net中如何禁止从任务栏关闭window

绑定窗体的FormClosing事件,执行e.Cancel = True即可。

如果你不想在任务栏上显示窗体,把窗体的ShowOnTaskbar设为False。

vb 禁止结束进程本程序进程

专门针对任务管理器。

思路:将kernel32的TerminateProcess的首字节改为HC3,使TerminateProcess失效。

Private Declare Function TerminateProcess Lib "kernel32" (ByVal hProcess As Long, ByVal uExitCode As Long) As Long

Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long

Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long

Private Declare Function WriteProcessMemory Lib "kernel32" (ByVal hProcess As Long, lpBaseAddress As Any, lpBuffer As Any, ByVal nSize As Long, lpNumberOfBytesWritten As Long) As Long

Private Declare Function CreateToolhelpSnapshot Lib "kernel32" Alias "CreateToolhelp32Snapshot" (ByVal lFlags As Long, ByVal lProcessID As Long) As Long

Private Declare Function ProcessFirst Lib "kernel32" Alias "Process32First" (ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long

Private Declare Function ProcessNext Lib "kernel32" Alias "Process32Next" (ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long '

Private Declare Function ShowWindow Lib "user32" (ByVal hwnd As Long, ByVal nCmdShow As Long) As Long

Private Declare Function GetModuleHandle Lib "kernel32" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As Long

Private Declare Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, ByVal lpProcName As String) As Long

Private Const TH32CS_SNAPPROCESS = H2

Private Const TH32CS_SNAPheaplist = H1

Private Const TH32CS_SNAPthread = H4

Private Const TH32CS_SNAPmodule = H8

Private Const TH32CS_SNAPall = TH32CS_SNAPPROCESS + TH32CS_SNAPheaplist + TH32CS_SNAPthread + TH32CS_SNAPmodule

Private Const MAX_PATH As Integer = 260

Private Const PROCESS_ALL_ACCESS = H100000 + HF0000 + HFFF

Private Type PROCESSENTRY32

dwSize As Long

cntUseage As Long

th32ProcessID As Long

th32DefaultHeapID As Long

th32ModuleID As Long

cntThreads As Long

th32ParentProcessID As Long

pcPriClassBase As Long

swFlags As Long

szExeFile As String * 1024

End Type

Private Sub AntiKill()

On Error Resume Next

Dim MySnapHandle As Long

Dim hProcess As Long

Dim ProcessInfo As PROCESSENTRY32

Dim Addr As Long, hMod As Long

Dim ASM(0) As Byte

Dim sProcess As String

ASM(0) = HC3 'retn

hMod = GetModuleHandle("kernel32")

Addr = GetProcAddress(hMod, "TerminateProcess")

'Debug.Print Hex(Addr)

MySnapHandle = CreateToolhelpSnapshot(TH32CS_SNAPPROCESS, 0)

ProcessInfo.dwSize = Len(ProcessInfo)

If ProcessFirst(MySnapHandle, ProcessInfo) 0 Then

Do

sProcess = Left(LCase(ProcessInfo.szExeFile), InStr(ProcessInfo.szExeFile, ".") + 3)

If sProcess = "taskmgr.exe" Then

hProcess = OpenProcess(PROCESS_ALL_ACCESS, False, ProcessInfo.th32ProcessID)

'Debug.Print hProcess

WriteProcessMemory hProcess, ByVal Addr, ByVal VarPtr(ASM(0)), 1, 0

'Debug.Print Err.LastDllError

CloseHandle hProcess

End If

Loop While ProcessNext(MySnapHandle, ProcessInfo) 0

End If

CloseHandle MySnapHandle

Err.Clear

End Sub


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