作者:兰花m123_680 | 来源:互联网 | 2023-01-30 17:41
目前,我正在使用以下代码来测试CTRL+ ALT+ DEL屏幕是否可见以及是否按预期工作。问题是,轮询此信息会消耗CPU,并且我正在寻找基于事件的选项。有谁知道另一种方法来检测此屏幕是否可见?
我只需要知道何时关闭此屏幕。我不在乎它何时打开。只是它已经打开,现在已关闭。
老实说,我找到了这段代码,但我不确定它是如何具体针对我所指的屏幕的。它似乎在寻找任何进程创建和删除事件。这意味着该屏幕必须打开一个新进程。知道该进程名称也将有所帮助。
var interval = new TimeSpan(0, 0, 3);
const string isWin32Process = "TargetInstance isa \"Win32_Process\"";
// Listen for started processes.
WqlEventQuery startQuery = new WqlEventQuery("__InstanceCreationEvent", interval, isWin32Process);
var _startWatcher = new ManagementEventWatcher(startQuery);
_startWatcher.Start();
_startWatcher.EventArrived += OnStartEventArrived;
// Listen for closed processes.
WqlEventQuery stopQuery = new WqlEventQuery("__InstanceDeletionEvent", interval, isWin32Process);
var _stopWatcher = new ManagementEventWatcher(stopQuery);
_stopWatcher.Start();
_stopWatcher.EventArrived += OnStopEventArrived;
该屏幕的名称是什么?以及如何检测这种类型的窗口?似乎与登录窗口的类型相同。
1> Adrian..:
当您按下CTRL+ ALT+ DEL,Windows切换到另一种特殊的虚拟桌面一个是主机winlogon
,负责用户进程登录/注销/锁定等操作。通过将WinAPI函数SetWinEventHook
与EVENT_SYSTEM_DESKTOPSWITCH
参数一起使用,您可以设置一个回调函数,该回调函数在发生此类桌面切换时被调用:
//Store the callback in a variable so that it is not GC'd private static
private static readonly WinEventDelegate callback = EventCallback;
static void StartListeningForDesktopSwitch()
{
SetWinEventHook(EVENT_SYSTEM_DESKTOPSWITCH, EVENT_SYSTEM_DESKTOPSWITCH,
IntPtr.Zero, callback, 0, 0, WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNTHREAD);
}
static void EventCallback(IntPtr hWinEventHook, uint eventType,
IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime)
{
Console.WriteLine("Desktop switched");
}
注意:如果要在控制台应用程序中使用此功能,则必须通过添加一个hidden来添加消息循环Form
:
static void Main(string[] args)
{
StartListeningForDesktopSwitch();
// Run message loop
Application.Run(new HiddenForm());
}
private class HiddenForm : Form
{
public HiddenForm()
{
this.FormBorderStyle = FormBorderStyle.None;
this.WindowState = FormWindowState.Minimized;
this.ShowInTaskbar = false;
}
}
delegate void WinEventDelegate(IntPtr hWinEventHook, uint eventType,
IntPtr hwnd, int idObject, int idChild, uint dwEventThread,
uint dwmsEventTime);
[DllImport("user32.dll")]
static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr
hmodWinEventProc, WinEventDelegate lpfnWinEventProc, uint idProcess,
uint idThread, uint dwFlags);
const uint WINEVENT_OUTOFCOnTEXT= 0x0000;
const uint WINEVENT_SKIPOWNTHREAD = 0x0001;
const uint EVENT_SYSTEM_DESKTOPSWITCH = 0x0020;
进一步:当用户按下Win+ L或弹出UAC窗口时,也会发生桌面切换。因此,我们需要一种检测其他情况的方法。UAC的情况相当琐碎,足以consent.exe
在回调函数期间检查进程是否正在运行:
var processes = Process.GetProcessesByName("consent");
if (processes.Length == 0)
Console.WriteLine("This is not a UAC prompt");
不幸的是,另一种情况更为复杂。我只是设法检测出用户从锁定屏幕返回的信息,但是没有检测到用户是否输入了锁定信息(如您所说,这与您无关,但无论如何我都想提一下)。
可以通过侦听SystemEvents.SessionSwitch
我们的事件来检测会话是否被锁定
HiddenForm
。该SessionSwitchEventArgs.Reason
属性设置为SessionSwitchReason.SessionLock
如果这是一个锁事件,并且SessionSwitchReason.SessionUnlock
如果用户解锁。当我们切换回默认桌面时,我们只能说出桌面切换是否不是锁定屏幕桌面,因为切换桌面事件回调在会话锁定之前和会话解锁之后被调用。这导致示例控制台应用程序的以下代码:
private static readonly WinEventDelegate callback = EventCallback;
static void Main(string[] args)
{
SetWinEventHook(EVENT_SYSTEM_DESKTOPSWITCH,
EVENT_SYSTEM_DESKTOPSWITCH, IntPtr.Zero, callback, 0, 0,
WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNTHREAD);
Application.Run(new HiddenForm());
}
private class HiddenForm : Form
{
public HiddenForm()
{
this.FormBorderStyle = FormBorderStyle.None;
this.WindowState = FormWindowState.Minimized;
this.ShowInTaskbar = false;
SystemEvents.SessionSwitch += SystemEvents_SessionSwitch;
}
private void SystemEvents_SessionSwitch(object sender, SessionSwitchEventArgs e)
{
if (e.Reason == SessionSwitchReason.SessionUnlock)
wasUnlocked = true;
}
}
static bool wasUnlocked = false;
static bool wasOpened = false;
static void EventCallback(IntPtr hWinEventHook, uint eventType,
IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime)
{
// Check if UAC dialog is being shown
var processes = Process.GetProcessesByName("consent");
if (processes.Length == 0)
{
if (wasOpened)
{
if (!wasUnlocked)
Console.WriteLine("Exited from CTRL+ALT+DEL");
wasUnlocked = false;
wasOpened = false;
}
else
wasOpened = true;
}
}
delegate void WinEventDelegate(IntPtr hWinEventHook, uint eventType,
IntPtr hwnd, int idObject, int idChild, uint dwEventThread,
uint dwmsEventTime);
[DllImport("user32.dll")]
static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr
hmodWinEventProc, WinEventDelegate lpfnWinEventProc, uint idProcess,
uint idThread, uint dwFlags);
const uint WINEVENT_OUTOFCOnTEXT= 0x0000;
const uint WINEVENT_SKIPOWNTHREAD = 0x0001;
const uint EVENT_SYSTEM_DESKTOPSWITCH = 0x0020;
a这种类型的虚拟桌面与Windows 10中新引入的“虚拟桌面”功能无关