Splashscreen image location error

[LHTXQ]

Describe the bug
When splashScreen is used, the image is not at the centre of the screen but at the upper-left of the application window.

To Reproduce
Steps to reproduce the behavior:

1. add a splashscreen image to your app.
2. start app.

Expected behavior
The Splashscreen image will be placed in the centre of the screen until it disappears.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. Windows 11]
• .NET: [e.g. net6]
• Version: [e.g. 2.0.2]

[LHTXQ]

When use the default UI, don't need to manually control the SplashScreen, which automatically appears in the middle of the screen.

[pomianowski]

Hey @LHTXQ , could you please share a link to a repository that uses splash screen this way?

[LHTXQ]

Hey @LHTXQ , could you please share a link to a repository that uses splash screen this way?

I packed it into a ZIP file.

VirtualMechanicalLaboratory-外发.zip

For #331 , click the test button at the top-right corner. For #299 , open the "about" window in "More" menu, I want to hide the close button of it. For #319 , A: open app , maxmize it and reopen it. B: See progressbar at the bottom.