Nadav and the wonders of the web

I guess this is quite the easy one but the fact is that while I was searching the web for this answer it was very hard to find.

This is something I knew and forgot so it is good that I will have it here for future quick reference.

Just use:

Environment.TickCount

This will return the time in milliseconds that has passed since the last boot.

Quick Note:

I have read here that this might overflow on systems running for a few days, they also give a solution. as I am using this for a Windows Mobile device I don’t have that option. (CF.Net being deprecated and all…)

Hope you found this faster then I did.

Update:

After further looking into this I have found a nice article about how to overcome the overflow problem, here is the solution:

public static TimeSpan GetTimeSinceBoot()
{
    long _newTicks = Convert.ToInt64("0x" + Environment.TickCount.ToString("X"), 16);

    int days = (int) (_newTicks/(1000*60*60*24));
    int hours = (int) ((_newTicks/(1000*60*60)) - (days*24));
    int minutes = (int) ((_newTicks/(1000*60)) - (days*24*60) - (hours*60));
    int seconds = (int) ((_newTicks/1000) - (days*24*60*60) - (hours*60*60) - (minutes*60));
    int milliseconds =
        (int) (_newTicks - (days*24*60*60*1000) - (hours*60*60*1000) - (minutes*60*1000) - (seconds*1000));

    return new TimeSpan(days, hours, minutes, seconds, milliseconds);
}

The ticks represent milliseconds and when I just call the constructor for TimeSpan it doesn’t treats it this way, that is why i am doing all of this.

Good luck,

Nadav

This topic is one I have been spending some time studying.
How do you get your program to the foreground when a certain event accurse ?

The answer is quite simple actually, you just need to call a UI component. like:

MessageBox.Show("Show Me");

And it will show the top most form in your application. Another thing you can do is call a form with Show().

Now, for a little bonus I have for you the…

How to send it back to the background!

What we need to do here is to call Hide() on all the visible forms in our application, this will essentially cause all our UI to go to the background and will bring back the last active application.

A little hint, you might want to use what you learned, and combine it with the previous post ;].

Nadav

Sometimes we want to be notified of different events that happen in the operating system, even when we are not “looking”. the State and Notification broker is built especially for this.

I will give an example of how to be notified when the current active application changes and how to handle it.

First create the correct SystemState member:

SystemState _activeProgram = new SystemState(SystemProperty.ActiveApplication);

Now set the event handler on your program initiation:

_activeProgram.Changed += new ChangeEventHandler(_activeProgram_Changed);

Now handle it ;]:

void _activeProgram_Changed(object sender, ChangeEventArgs args)
{
    MessageBox.Show(((string)args.NewValue));
}

You would want to know a few interesting things:

1. The NewValue string is formatted in this way:

   PreviousActiveProgramNameCurrentActiveProgramName

   So, you might want to use StartsWith\EndsWith methods in order to check them ;].

2. It seams that every UI involved action(MessageBox, Form, etc.) causes your own application to come back from the background(if it was there) and show itself ;]. while other non-UI related actions does not cause this. This only a major “feeling” i got from my little workings with this so far, i checked this with a Thread.Sleep that did not cause my application to come to the foreground.

Hope this helps.

Nadav