嗨，我一直在寻找，但我找不到答案。我怎么知道屏幕何时关闭或打开。不是 SystemEvents.PowerModeChanged 。我不知道如何检索显示/屏幕事件
private const int WM_POWERBROADCAST = 0x0218;
private const int WM_SYSCOMMAND = 0x0112;
private const int SC_SCREENSAVE = 0xF140;
private const int SC_CLOSE = 0xF060; // dont know
private const int SC_MONITORPOWER = 0xF170;
private const int SC_MAXIMIZE = 0xF030; // dont know
private const int MONITORON = -1;
private const int MONITOROFF = 2;
private const int MONITORSTANBY = 1;
[DllImport("user32.dll")]
//static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
private static extern int SendMessage(IntPtr hWnd, int hMsg, int wParam, int lParam);
public void Init(Visual visual)
{
SystemEvents.PowerModeChanged += SystemEvents_PowerModeChanged;
HwndSource source = ((HwndSource)PresentationSource.FromVisual(visual));
source.AddHook(MessageProc);
Handle = source.Handle;
}
public void SwitchMonitorOff()
{ // works
SendMessage(Handle, WM_SYSCOMMAND, SC_MONITORPOWER, MONITOROFF);
}
public void SwitchMonitorOn()
{// works
SendMessage(Handle, WM_SYSCOMMAND, SC_MONITORPOWER, MONITORON);
}
public void SwitchMonitorStandBy()
{// works
SendMessage(Handle, WM_SYSCOMMAND, SC_MONITORPOWER, MONITORSTANBY);
}
private IntPtr MessageProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (msg == WM_SYSCOMMAND) //Intercept System Command
{
// not finished yet
// notice the 0xFFF0 mask, it's because the system can use the 4 low order bits of the wParam
// value as stated in the MSDN library article about WM_SYSCOMMAND.
int intValue = wParam.ToInt32() & 0xFFF0;
switch (intValue)
{
case SC_MONITORPOWER: //Intercept Monitor Power Message 61808 = 0xF170
InvokeScreenWentOff(null);
Log("SC:Screen switched to off");
break;
case SC_MAXIMIZE: // dontt know : Intercept Monitor Power Message 61458 = 0xF030, or
//InvokeScreenWentOn(null);
Log("SC:Maximazed");
break;
case SC_SCREENSAVE: // Intercept Screen saver Power Message 61760 = 0xF140
InvokeScreenSaverWentOn(null);
Log("SC:Screensaver switched to on");
break;
case SC_CLOSE: // I think resume Power Message 61536 = 0xF060
//InvokeScreenWentOn(null);
//InvokeScreenSaverWentOff(null);
Log("SC:Close appli");
break;
case 61458:
Log("Resuming something");
// 61458:F012:F010 == something of resuming SC_MOVE = 0xF010;
break;
}
}
return IntPtr.Zero;
}
编辑
也许我可以解释我的意图，所以也许有更好的解决方案。我有一个双绑定 WCF 服务正在运行。它在爱可视（便携式平板电脑）上运行。我希望当用户在空闲时间停止工作时，连接立即关闭，当计算机从空闲状态返回时，他立即重新连接。Tom提出的Application Idle on Code 项目的想法已经是一个好主意。耗电越少越好。启动必须尽可能快。