c# - Why does Visual Studio automatically changes the layout of my form?

Question

I have a Windows form which consists of 3 files:

• AbcFrm.cs

• AbcFrm.Designer.cs

• AbcFrm.resx

Whenever I do a little change to any properties of datagridview or add new events, the size of the controls grows larger to the right and bottom side and causes some part of the controls to go out of bounds.

I have compared the .Designer.cs file before and after I perform a minor property change (e.g. change a datagridview's tabStop property value from true to false) and discovered some lines/properties were added/changed automatically in the .Designer.cs file :

• some controls' .Size value changes
• some controls' .Location value changes
• some controls' .Padding value changes
• the form's .AutoScaleDimensions becomes larger
• the form's .ClientSize becomes larger

Edit

I realize when I change the resolution from 150% to 125% and reopen the application, the controls are back in the correct place due to the windows form is now having a larger scaling size. My problem is similar to this question

The cause is that the code might have been edited in a computer with different resolution. However, the solution is not satisfying as it does not solves the problem, only identifying the cause.

How do I prevent this from happening? I'm using Visual Studio 2010 and my OS is Windows 10.

Answer 1

Reasoning

This was due to AutoScaleMode property which scales the size and position of objects in winforms based on the difference in Dots per inch (DPI) between different development machines. This is a feature that cannot and should not be changed. For official documentation, see Automatic Scaling in Windows Forms on MSDN.

Let's say there are two machines, machine A and B. Machine A has 96 DPI and scaling factor 100%. Machine B has 144 DPI and 150% scaling factor as its recommended settings. A WinForm was created in machine A and machine B is trying to edit that WinForm.

When Visual Studio in machine B encounters that machine B's DPI is different than the one used to create the WinForm, it automatically scales the objects in the WinForm to try to make the WinForm appear in machine B as how it would look in machine A??. Hence, this causes some properties in WinForm.Designer.cs file to be automatically changed.

Workaround

In order to continue editing WinForms in high DPI machines without any automatic alignments, we need to set the DPI in high DPI machines to match the DPI in the machines used to create the WinForm. This can be done by adjusting the scaling factor to 100% (96 DPI; right-click on desktop > Display settings) and restarting Visual Studio (or re-login to Windows, if that does not work).

NOTE: The key here is to adjust the DPI to the original DPI of the machines used to create the WinForm. Just adjusting the scaling factor might not work. You might need to play around with the screen resolution.