My Windows Form keeps on shrinking/resizing on bui

Question

I am working on a Windows Forms project. It contains a tab controller with multiple pages and multiple controls on each.

It appears that relatively recently, after some form changes, that each time I build and run the solution the form resizes/shrinks.

So if I set the size of the form height to 768, once I click 'Start' to build and run it, I can actually catch a glimpse of it resizing itself during the process and then the form loads 21 pixels shorter than the height value it was at build for.

If I then keep building and running my project, the form will decrease by 21 pixels each time, making it smaller and smaller with every build.

We think it might have been introduced when we added the 'DataGridView' controller to one of the tabs, but we have yet to prove if that's the case.

Is there a reason why this would be happening, and what could be doing this? Why would it resize itself during build run time?

Answer 1

The Problem

Apparently there is a bug in Visual Studio 2015. It is not calculating the Size properly when certain circumstances are met. In my case I was using the following...

(Name):           Form1
AutoScaleMode:    Font
AutoSizeMode:     GrowOnly
DoubleBuffered:   True
Font:             Verdana, 8.25pt
FormBorderStyle:  FixedDialog
Icon:             (Icon)
MaximizeBox:      False
MinimizeBox:      False
MinimumSize:      600, 170
Size:             600, 170
StartPosition:    CenterParent
Text:             MyTitle

Now... If you close this form and open it back up the Size is still exactly the same (600, 170). If you change the following property...

ControlBox:       False

Then you closes the form and open it back up you will notice the Size has now been changed to (610, 203).

My guess is that the bug is not accounting for two things. One would be the form title bar HEIGHT. The other would be the title bar icon WIDTH. This would be the offset of a WIDTH of 10 pixels and a HEIGHT of 33 pixels.

The Solution

Well you actually have three workarounds. One would be to offset the MinimumSize. Another would be to actually show the ControlBox. The last one would be to fix the issue in code by setting the ControlBox property after the form is initialized.

Offsetting The MinimumSize:

So the first option would be to offset what you want the MinimumSize to be by (w:10, h:33). So for example, If you want the MinimumSize to be (600, 170) then you need to set it to (590, 137). That would actually produce the size you expect to see.

Showing the ControlBox:

Simply change the following property...

ControlBox:       True

Correcting the issue with code:

You will need to change the following property at design-time...

ControlBox:       True

Then you will need to set the ControlBox property to False after the form is initialized.

public Form1()
{
    InitializeComponent();
    this.ControlBox = false;
}

Answer 2

This is an annoying bug, and I have suffered similar behavior myself. However, there maybe a couple of workarounds, however be warned though, these may or may not help and sound a little hacky.

Solution 1

If your control isn't docked, docking may help.

Solution 2

You might be able to change your DPI settings to eliminate the problem, i.e.:

Display Properties → Settings tab → Advanced. In the the Advanced dialog I changed the "DPI Settings" from Large (120 dpi) to Normal (96 dpi).

Solution 3

This is maybe due to AutoScaleMode-property. Your forms may have been designed with a different DPI or font settings than you have now in Windows display settings. Try setting the AutoScaleMode-property to None in your form and offending controls, and they won't be automatically re-sized anymore.

Answer 3

I had the same problem. My solution:

My PC's system is Windows 10. The resolution of the monitor was 125%, and I set it to 100%. Then I set the size of the form, not changed.

You can see the resolution settings in this picture:

In Turkish "Scale" is "Ölçekle". There are resolution options on the bottom ("ölçekle ve düzenle").

Answer 4

1. Copy the values of your form size.
2. Past it in both Minimum and Maximum Size property.
3. Enjoy

Answer 5

OK, so first in response to Saruman's suggested solutions..

1. None of the controllers in the application where had docked values. A good few were anchored, but none appeared docked. I docked a couple of the main containers I could find, and it didn't seem to make much difference. Admittedly I didn't dock every single controller, but I then moved onto solution 2...

2. I wasn't sure where to find the DPI settings. Whether somewhere in Visual Studio, or on my machine. So I moved onto proposed solution 3...

3. On the Form initialize, I added 'this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None;'. This then seemed to automatically place it above a 'this.ClientSize = new System.Drawing.Size(11264,730)' method, which piqued my interest.

   With a little further debugging, it appears that when the application builds and intializes, the 'this.ClientSize' property is already set at a very low, more or less, '230x200'. I am not sure where this value comes from, but I wonder if it has anything to do with the initial resizing before it then tries to set it again to something bigger...

Regardless, I came across another suggestion to possibly double check my form's minimum width and height properties, and noticed they were set to 0x0, I'm assuming by default.

So I set the minimum values to be the same as my form's size value, and on subsequent builds it appears to be keeping its size now! Or at least, it isn't shrinking any more from what I can tell.

I'm not sure if setting the minimum form size is an acceptable solution for this bizarre behaviour, but so far it seems to be keeping the application size consistent on each build we do, which is a relief at the moment.

If any one has further knowledge on the ClientSize property and if I am right to be concerned about its initial low size, would be great to hear it. :)

Answer 6

I figured it out!

If you click on the form in "Design View" → "Properties" → "MinimizeBox" and change "True" to "False".