CODEWITHSUNDEEP
windowsdelphi
user1579166
user1579166

Reputation: 137

How to center a Delphi form on a 4k screen? (Windows scaling enabled) - poScreenCenter not working

I have a Delphi form functioning as a sort of splash screen (i.e. borderless) that I want to appear exactly in the center of the (main) screen (currently using TForm1.Position := poScreenCenter to achieve this).

This is not working on 4k monitors with scaling (or any screen really that uses a percentage higher than 100% in Windows (Settings > Display > Scale and Layout)). In such cases, the form will pop up more in the upper left-hand corner rather than the exact middle of the screen. This seems like a HiDPI-related bug in Delphi, as the program looks otherwise fine and works well.

My guess is that I would have to set TForm1.Position to poDesigned and manually set TForm1.Top and Left in the OnShow event. The question is: To what? What would be a universal solution to ensure that the form always appears in the exact screen center, regardless of monitor size / resolution / scaling etc. I have stumbled across a function called "muldiv" that may be of help but I am unsure how to use it.

I have:

Thanks for your help.

Upvotes: 3

Views: 2552

Answers (3)

Wellington Telles Cunha
Wellington Telles Cunha

Reputation: 373

I tried almost the same, but I got new information from Embarcadero:

frmMain.Position := TFormPosition.ScreenCenter;

It works for me. My monitor is using 150% scale.

Upvotes: 0

Mehrdad Shoja
Mehrdad Shoja

Reputation: 57

Or use this:

Form1.Left := (Screen.WorkAreaRect.Width  - Form1.Width)  div 2;
Form1.Top  := (Screen.WorkAreaRect.Height - Form1.Height) div 2;

Upvotes: 0

fpiette
fpiette

Reputation: 12292

To center the form, use this code:

Form1.Left := (Form1.Monitor.Width  - Form1.Width)  div 2;
Form1.Top  := (Form1.Monitor.Height - Form1.Height) div 2;

Of course you may check that the form is not bigger than the monitor.

Upvotes: 6

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