C# Event not detecting suspend state-CodePudding

I'm working on a Windows forms application that needs to perform some logic before the PC goes to sleep. I've looked through many threads and found this which should work perfectly: Link. I can detect when the power is plugged/unplugged just fine, but I've run into serious problems when trying to detect a sleep/suspend event.

Using the logic mentioned, I have this section of code in my program:

public void powerModeChanged(object sender, PowerModeChangedEventArgs args)
{
    if (args.Mode == PowerModes.Suspend)
    {
        Trace.WriteLine("Sleeping.....");
    }
    else if (args.Mode == PowerModes.StatusChange)
    {
        Trace.WriteLine("Other Status Change:");
    }
}

public MainPage()
{
    InitializeComponent();
    SystemEvents.PowerModeChanged  = new PowerModeChangedEventHandler(powerModeChanged);

Per this documentation page - Link, there are 3 types of power modes. The statusChange is detected as expected when I unplug and replug the power adapter into my laptop, and prints to the debug Window just fine. However, it will not detect when I put the computer to sleep. After going over this for hours, my conclusion is that what the version of Windows 10 I'm running defines as "sleep" doesn't match up with the event that I'm checking for.

There is a comment on that initial thread in the first link that says the solution I tried doesn't seem to work with the "new Connected/Modern Standby modes" and provides a link to this thread: Link where it describes using the session switch event handler instead. This works on my laptop as my laptop locks upon sleep, but when testing on a Surface tablet (which is our target device for operation), it doesn't work due to the surface not locking upon sleep.

Of course, I could just set the device to lock on sleep, and that may end up being the only solution, but I wanted to see if there was something I was overlooking or any other way to check for sleep in modern versions of Windows. As it stands, I would hate for this important feature of the application depend on the system having to be setup to lock when sleeping. Thanks!

CodePudding user response：

You could use the SystemEvents.PowerModeChanged event to detect when the computer is about to go to sleep. Within the event handler, you can perform any logic that needs to be done before the computer goes to sleep. For example, you could write commands to the windows registry or perform some other related tasks.

Below is an example of how this could be done:

// Register the SystemEvents.PowerModeChanged event handler 
SystemEvents.PowerModeChanged  = SystemEvents_PowerModeChanged;

// Event handler for SystemEvents.PowerModeChanged
private void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
    // Check if the computer is about to go to sleep
    if (e.Mode == PowerModes.Suspend)
    {
        // Perform the logic that needs to be done before the computer goes to sleep
        // ...
    }
}

CodePudding user response：

I ended up finding this thread, the answer on that thread solves this issue. Link to Solution