winapi - 以编程方式阻止 Windows 屏幕保护程序启动

Question

是否有推荐的方法来阻止 Windows 屏幕保护程序启动？我发现的最接近的是 this article ，但我真正想做的是告诉 Windows 计算机没有空闲，而不是愚弄当前设置的屏幕保护程序值。

Answer 1

为了测试，我将屏幕保护程序设置为 1 分钟并需要密码。

我 try catch SC_SCREENSAVE 并在 VB .Net 中返回 -1。正如所评论的，它在没有屏幕保护程序密码时有效，但如果屏幕保护程序密码处于事件状态，则失败。 (我在Windows XP 中尝试过)。我还将其放入计时器的滴答事件中，每 1000 毫秒一次:

Static dir As Integer = 4
Cursor.Position = Cursor.Position + New Size(dir, dir)
dir = -dir

这不起作用。光标来回晃动，1 分钟后屏幕保护程序会短暂闪烁，然后关闭。屏幕保护程序只打开一会儿，不足以要求输入密码。但是，闪光灯还是很难看。

然后我尝试使用user32.dll的SetCursorPos和GetCursorPos。您可以在 pinvoke 上查找它们。与上面的结果相同。

然后我看了一眼这个问题其他地方提到的“JiggleMouse”的代码。 JiggleMouse 使用 SendInput。 SendInput 有效! 屏幕保护程序不闪烁。我在计时器内调用了 SendInput，每 50 秒触发一次(略小于屏幕保护程序的最小超时时间 60 秒)。将鼠标移动 0,0 增量就足够了，没有真正的移动。这确实有效。放入 Tick 事件的代码:

Dim i(0) As INPUT
i(0).dwType = INPUT.InputType.INPUT_MOUSE
i(0).mkhi = New MOUSEKEYBDHARDWAREINPUT
i(0).mkhi.mi = New MOUSEINPUT
i(0).mkhi.mi.dx = 0
i(0).mkhi.mi.dy = 0
i(0).mkhi.mi.mouseData = 0
i(0).mkhi.mi.dwFlags = MOUSEINPUT.MouseEventFlags.MOUSEEVENTF_MOVE
i(0).mkhi.mi.time = 0
i(0).mkhi.mi.dwExtraInfo = IntPtr.Zero
SendInput(1, i(0), Marshal.SizeOf(i(0)))

这来自 pinvoke.com:

Public Declare Function SendInput Lib "user32" (ByVal nInputs As Integer, ByRef pInputs As INPUT, ByVal cbSize As Integer) As Integer

Public Structure INPUT
    Enum InputType As Integer
        INPUT_MOUSE = 0
        INPUT_KEYBOARD = 1
        INPUT_HARDWARE = 2
    End Enum

    Dim dwType As InputType
    Dim mkhi As MOUSEKEYBDHARDWAREINPUT
End Structure

Public Structure MOUSEINPUT
    Enum MouseEventFlags As Integer
        MOUSEEVENTF_MOVE = &H1
        MOUSEEVENTF_LEFTDOWN = &H2
        MOUSEEVENTF_LEFTUP = &H4
        MOUSEEVENTF_RIGHTDOWN = &H8
        MOUSEEVENTF_RIGHTUP = &H10
        MOUSEEVENTF_MIDDLEDOWN = &H20
        MOUSEEVENTF_MIDDLEUP = &H40
        MOUSEEVENTF_XDOWN = &H80
        MOUSEEVENTF_XUP = &H100
        MOUSEEVENTF_WHEEL = &H800
        MOUSEEVENTF_VIRTUALDESK = &H4000
        MOUSEEVENTF_ABSOLUTE = &H8000
    End Enum

    Dim dx As Integer
    Dim dy As Integer
    Dim mouseData As Integer
    Dim dwFlags As MouseEventFlags
    Dim time As Integer
    Dim dwExtraInfo As IntPtr
End Structure

Public Structure KEYBDINPUT
    Public wVk As Short
    Public wScan As Short
    Public dwFlags As Integer
    Public time As Integer
    Public dwExtraInfo As IntPtr
End Structure

Public Structure HARDWAREINPUT
    Public uMsg As Integer
    Public wParamL As Short
    Public wParamH As Short
End Structure

Const KEYEVENTF_EXTENDEDKEY As UInt32 = &H1
Const KEYEVENTF_KEYUP As UInt32 = &H2
Const KEYEVENTF_UNICODE As UInt32 = &H4
Const KEYEVENTF_SCANCODE As UInt32 = &H8
Const XBUTTON1 As UInt32 = &H1
Const XBUTTON2 As UInt32 = &H2

<StructLayout(LayoutKind.Explicit)> Public Structure MOUSEKEYBDHARDWAREINPUT
    <FieldOffset(0)> Public mi As MOUSEINPUT
    <FieldOffset(0)> Public ki As KEYBDINPUT
    <FieldOffset(0)> Public hi As HARDWAREINPUT
End Structure