WinForms - Thicker Form Borders

12 February 2019

We are busy at this time working on v19.1 and implementing lots of awesome features based on your preferences – many thanks to all of you who voted in our survey! Meanwhile, we have just finished one feature that will become available in the minor update v18.2.6.

Application appearance is constantly evolving. Form borders have changed very much since the days of the thick and bulky Windows XP style, with sleek 1-pixel borders the common choice today. However, a form border is not just an ornamental element! It is a functional form part that enables users to resize the form by dragging the edges. The thinner a border is, the harder it is to point at for resizing. Fortunately there’s an easy solution: add form shadows to the resize region and you get 10-15 pixels of extra space. Many 3rd party applications – including Microsoft Office – use this approach, and so do DevExpress forms with their shadow and glow effects.

Form Border Shadow

Obviously, this technique doesn’t work when shadows are switched off. Shadows are not used for MDI child windows, and there are environments that don’t support semi-transparent windows, which are required to show shadows correctly.

To make form resizing easy in these cases, we have added three properties to the WindowsFormsSettings:

  • WindowsFormsSettings.FormThickBorder = true; switches on extra-thick form borders for stand-alone or MDI parent forms
  • WindowsFormsSettings.MdiFormThickBorder = true; activates the same borders for MDI child forms
  • WindowsFormsSettings.ThickBorderWidth = xx; sets the width of the thick borders in pixels. This property will be available starting with version 18.2.7.

Here’s what an MDI setup looks like with thick borders and the Office 2019 Colorful vector skin:

Thick Borders on MDI parent and child

We think it is important to pay attention to details like this. What do you think? Will you use thick borders in your apps?

17 comment(s)
T. Thijs

I will use it immediately. Never found it a good decision by Microsoft.

12 February, 2019
Engº Silvio Cruz

This is a must have....

12 February, 2019
Davide M

Very good. Useful in many cases.

12 February, 2019
Mike Calming

Great. I have my own form control with custom border, but will replace with this one. When are you planning releasing 19.1?

12 February, 2019
Reinhold Erlacher

I missed real borders since long time. Very good improvement!

12 February, 2019
Edhy Rijo

Hi Oliver, this is awesome, thanks.  Believe it or not, I use a custom framework and I just ported all my custom code my new form class based on XtraForm just to be able to use features like this one and more support for High DPI on WinForms.

12 February, 2019
Sigurd Decroos _


12 February, 2019
Christopher Todd

I like it a lot! Thanks!

12 February, 2019
Stephen J White

Yes, this is definitely a must have. I hope you can implement this in WPF too :)

12 February, 2019
Stefan Remberg

This is definitely a must have. Nice!

13 February, 2019
Dmitry Babich (DevExpress)


Version 19.1 is likely to become available in May. If you are looking for the Thicker Form Borders feature - it's already available in version 18.2.6, which can be downloaded in the Download Manager.

13 February, 2019
Stefan Ziegler

Thank you, that's a very good feature.

However, I cannot find the property "WindowsFormsSettings.ThickBorderWidth" in v18.2.6.

Should that be available?

13 February, 2019
Sara Radmaneshs

Very good...THANKS.

13 February, 2019
Mike Calming

Thanks Dmitry, just updates controls and indeed we have both

FormThickBorder and MdiFormThickBorder, but ThickBorderWidth is missing.

13 February, 2019
Dmitry Babich (DevExpress)

@Stefan @Mike

My apologies for the confusion. The ThickBorderWidth property will be available starting with version 18.2.7. I've updated the blog post accordingly.

14 February, 2019
Robert Perry 1

This is a 'little bit' lame.. Did it take like 5 minutes for a developer to add a property to a class for this feature? Come on guys...

15 February, 2019
Baldur Fürchau

I didn't need this feature. Thick borders takes too much space for datapresentation.

Even if i use Dock/Document-Manager, it is heavy to remove the sometimes extrem thick borders around the panels with skineditor.

If i need a resizable windows, i can put a "grabber" on the down right edge of each dialog.

I will never use this fetaure.

16 February, 2019

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