Weird Quirk

My desktop PC (Intel i5 w 16 GB RAM) has two 1920x1080 displays. The
main display has a double height taskbar at the bottom. The secondary
display is set to not display any taskbar. The secondary display
shows the output of a C# program that is written to display sixteen
480x270 jpeg images in a 4x4 pattern thereby completely filling the
1920x1080 space on the monitor. This setup has been working perfectly
for years. About three months ago, I noticed a short strip of pixels
at the bottom where the background wallpaper was showing through. My
eye sight is not good enough to be sure, but I think the strip is 3
pixels high. If I go into taskbar settings and and set it to display
the task bar on both monitors, the strip goes away. (I would have
expected the taskbar to show up, but it didn't. I then turn that
feature back off and the strip is still gone. However, if I restart
windows, the strip comes back until I toggle the taskbar setting
again. Any ideas what would cause this? (Like I said, it started
about 3 months ago under 1909, but I recently upgraded to 2004 and the
same symptom is there. Installing the latest Intel graphics driver
had no effect either.) Not a big deal, but I would love to understand
the cause.

Pat

Pat wrote:

My eye sight is not good enough to be sure, but I think the strip
is 3 pixels high.

Use Magnifier. You can zoom WAY in by holding control plus alt and
using the scroll wheel.

Pat wrote:
My desktop PC (Intel i5 w 16 GB RAM) has two 1920x1080 displays. The
main display has a double height taskbar at the bottom. The secondary
display is set to not display any taskbar. The secondary display
shows the output of a C# program that is written to display sixteen
480x270 jpeg images in a 4x4 pattern thereby completely filling the
1920x1080 space on the monitor. This setup has been working perfectly
for years.

About three months ago, I noticed a short strip of pixels
at the bottom where the background wallpaper was showing through. My
eye sight is not good enough to be sure, but I think the strip is 3
pixels high. If I go into taskbar settings and and set it to display
the task bar on both monitors, the strip goes away. (I would have
expected the taskbar to show up, but it didn't. I then turn that
feature back off and the strip is still gone.)

However, if I restart windows, the strip comes back until I toggle
the taskbar setting again. Any ideas what would cause this? (Like I
said, it started about 3 months ago under 1909, but I recently upgraded
to 2004 and the same symptom is there. Installing the latest Intel
graphics driver had no effect either.) Not a big deal, but I would
love to understand the cause.

Pat

You can use Winlister to get a list of decorations
on the screen (windows and parts of windows), and they
have dimensions listed. Maybe you can gather more info from that,
as to what has changed.

https://i.postimg.cc/xCF9Xh6j/winlister.gif

https://www.nirsoft.net/utils/winlister.html
https://www.nirsoft.net/utils/winlister-x64.zip

The monitor resolution 1920x1080 is unlikely to have changed.

Horizontal is divisible by 8, vertical is divisible by 2.
An error involving the number 3 is unlikely to related to
a resolution change.

Paul

On Sun, 23 Aug 2020 08:38:58 -0400, Paul
wrote:

Pat wrote:
My desktop PC (Intel i5 w 16 GB RAM) has two 1920x1080 displays. The
main display has a double height taskbar at the bottom. The secondary
display is set to not display any taskbar. The secondary display
shows the output of a C# program that is written to display sixteen
480x270 jpeg images in a 4x4 pattern thereby completely filling the
1920x1080 space on the monitor. This setup has been working perfectly
for years.

About three months ago, I noticed a short strip of pixels
at the bottom where the background wallpaper was showing through. My
eye sight is not good enough to be sure, but I think the strip is 3
pixels high. If I go into taskbar settings and and set it to display
the task bar on both monitors, the strip goes away. (I would have
expected the taskbar to show up, but it didn't. I then turn that
feature back off and the strip is still gone.)

However, if I restart windows, the strip comes back until I toggle
the taskbar setting again. Any ideas what would cause this? (Like I
said, it started about 3 months ago under 1909, but I recently upgraded
to 2004 and the same symptom is there. Installing the latest Intel
graphics driver had no effect either.) Not a big deal, but I would
love to understand the cause.

Pat

You can use Winlister to get a list of decorations
on the screen (windows and parts of windows), and they
have dimensions listed. Maybe you can gather more info from that,
as to what has changed.

https://i.postimg.cc/xCF9Xh6j/winlister.gif

https://www.nirsoft.net/utils/winlister.html
https://www.nirsoft.net/utils/winlister-x64.zip

The monitor resolution 1920x1080 is unlikely to have changed.

Horizontal is divisible by 8, vertical is divisible by 2.
An error involving the number 3 is unlikely to related to
a resolution change.

Paul

Thank you for the WinLister suggestion. (Note that my secondary
monitor is to the left of my main monitor, so my full disktop is
3840x1080 but is located at -1920 to +1919.) After a restart,
WinLister tells me my C# program is located at -1920,0 and its size is
1920x1080. That is what I want, but the 3 pixel strip is showing at
the bottom of the screen. After I toggle the "show taskbar on all
displays" option, the strip disappears and Winlister tells me my
program is now located at -1920, 3. There's that wierd 3 number
again. I'm out of time right now, but I'll look at it some more
later. Thanks for your help.

On Sun, 23 Aug 2020 10:50:13 -0400, Pat
wrote:

On Sun, 23 Aug 2020 08:38:58 -0400, Paul
wrote:

Pat wrote:
My desktop PC (Intel i5 w 16 GB RAM) has two 1920x1080 displays. The
main display has a double height taskbar at the bottom. The secondary
display is set to not display any taskbar. The secondary display
shows the output of a C# program that is written to display sixteen
480x270 jpeg images in a 4x4 pattern thereby completely filling the
1920x1080 space on the monitor. This setup has been working perfectly
for years.

About three months ago, I noticed a short strip of pixels
at the bottom where the background wallpaper was showing through. My
eye sight is not good enough to be sure, but I think the strip is 3
pixels high. If I go into taskbar settings and and set it to display
the task bar on both monitors, the strip goes away. (I would have
expected the taskbar to show up, but it didn't. I then turn that
feature back off and the strip is still gone.)

However, if I restart windows, the strip comes back until I toggle
the taskbar setting again. Any ideas what would cause this? (Like I
said, it started about 3 months ago under 1909, but I recently upgraded
to 2004 and the same symptom is there. Installing the latest Intel
graphics driver had no effect either.) Not a big deal, but I would
love to understand the cause.

Pat

You can use Winlister to get a list of decorations
on the screen (windows and parts of windows), and they
have dimensions listed. Maybe you can gather more info from that,
as to what has changed.

https://i.postimg.cc/xCF9Xh6j/winlister.gif

https://www.nirsoft.net/utils/winlister.html
https://www.nirsoft.net/utils/winlister-x64.zip

The monitor resolution 1920x1080 is unlikely to have changed.

Horizontal is divisible by 8, vertical is divisible by 2.
An error involving the number 3 is unlikely to related to
a resolution change.

Paul

Thank you for the WinLister suggestion. (Note that my secondary
monitor is to the left of my main monitor, so my full disktop is
3840x1080 but is located at -1920 to +1919.) After a restart,
WinLister tells me my C# program is located at -1920,0 and its size is
1920x1080. That is what I want, but the 3 pixel strip is showing at
the bottom of the screen. After I toggle the "show taskbar on all
displays" option, the strip disappears and Winlister tells me my
program is now located at -1920, 3. There's that wierd 3 number
again. I'm out of time right now, but I'll look at it some more
later. Thanks for your help.


Update to Paul: I resolved the symptom by recompiling my C# program
with the windows state set to Maximize. In other words, it is now
running "full screen" on the 1920x1080 monitor instead of being a
1920x1080 window. Maybe there was a 3 pixel margin being drawn, but
why was it transparent and why only at the bottom. I guess that will
remain a mystery. Regardless, thanks for you help.

Pat