Function to save/restore last used form size/position with multiple monitor support

Question

Function to save/restore last used form size/position with multiple monitor support

Darren Rose 311

Can anyone recommend a good VB / C# function I can use to save/restore windows form size/position with multiple monitor support which covers issues like second monitor then being disconnected etc.

Have googled but most solutions I find have issues and are quite old and want to find a recommended / reliable solution, and I respect the opinion of those on here so thought I would ask.

Thank you

Anonymous

2023-09-17T15:53:32.04+00:00

Hi

Please explain a little more. I m assuming the 'normal' Form.Location and Form.Size are not what you are asking about - is that correct? If these ARE what you want to save and restore then it may be trivial.
Darren Rose 311 Reputation points

2023-09-17T15:56:03.67+00:00

I mean so that the next time the app is launched it will open in the last location and at the last size (and on the last monitor if still available) that the user had it
Anonymous

2023-09-17T16:29:23.2533333+00:00
Hi

As a starting point: Set up a couple of My.Settings. Add one lets say named FormSize as a Size type and the other lets say FormLoc as a Point type, see image below. (if you need further info on where to set these up, just ask) The names are arbitrary and you can name them as you see fit.

Each needs a default initial value. so lets say the FormSize is set to (500,400) and FormLoc is set to (100,100)

Once set up, in the Form code, add the following in the appropriate Load/Closing event handlers.

Option Strict On Option Explicit On Public Class Form1 Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing My.Settings.FormSize = Size My.Settings.FormLoc = Location End Sub Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load Size = My.Settings.FormSize Location = My.Settings.FormLoc End Sub End Class
Darren Rose 311 Reputation points

2023-09-17T16:43:57.0333333+00:00

Okay thanks, that works - until you close your app whilst on a second screen, disconnect the second screen and then open the app again, as it is opening the app off screen (on second screen which is no longer connected) so you can't see it - so we need some way of handling scenarios like that?
Anonymous

2023-09-17T16:52:16.59+00:00

Says you commented but doesn't let me see it. This is a post to jog this idiotic forum back to life.
Anonymous

2023-09-17T16:57:04.1+00:00

Hi

OK, that jogging worked and I can see your comment.

OK, this side of it is not something I have played with before. I will have a look to see what I can suggest, perhaps someone else will assist in the meantime.

BTW: there are a couple of ways that a second monitor can be used, such as shared in the sense that it forms one larger monitor, or as 2 separate monitors. Which are you using.
Darren Rose 311 Reputation points

2023-09-17T17:02:39.65+00:00

Thanks Les.

I was testing it as 2 separate monitors.

Also noticed doesn't remember if you have "maximized" the window - so suspect will need a third setting to save WindowState perhaps?
Anonymous

2023-09-17T17:25:30.9033333+00:00

Hi

You would need a third setting if you need to save/restore the state - perhaps a Boolean to indicate Maximized or not. If you want to include Minimized then a second one for that too.

Darren Rose 311

Code amended to handle Maximized state - not worried about minimized

Edit: amended to fix abnormal value when minimized as per KOZ6.0 response below

Option Strict On 
Option Explicit On 
Public Class Form1 	
	Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing 		
		If Me.WindowState = FormWindowState.Normal Then
        	My.Settings.FormSize = Size
        	My.Settings.FormLoc = Location
    	Else
        	My.Settings.FormSize = RestoreBounds.Size
        	My.Settings.FormLoc = RestoreBounds.Location
    	End If		
		If WindowState = FormWindowState.Maximized Then             				
			My.Settings.FormWindowStateMaximized = True         
		Else             
			My.Settings.FormWindowStateMaximized = False         
		End If 	
	End Sub 	
	Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load 		
		Size = My.Settings.FormSize 		
		Location = My.Settings.FormLoc 		
		If My.Settings.FormWindowStateMaximized = True Then             
			WindowState = FormWindowState.Maximized         
		End If 	
	End Sub 
End Class

Anonymous

2023-09-17T17:58:20.8266667+00:00
Hi

Unless someone else pops in to help, then you are the only source of a multiple monitor setup for testing. Would you try this adding these further lines of code to your project, run and see if you get a STOP when disconnecting second monitor. )see the code for the STOP location. This test is to discover if we can detect the second monitor disconnect.

add an Import at top of code:

Imports Microsoft.Win32

add an Event Handler in the Load Event for the Form:

AddHandler SystemEvents.DisplaySettingsChanged, AddressOf Test

add a Sub:

Sub Test(sender As Object, e As EventArgs) ' here is the STOP I need you to test for Stop End Sub
Darren Rose 311 Reputation points

2023-09-17T18:04:43.2766667+00:00

Yes that event triggers when disconnecting (and connecting) the second monitor

KOZ6.0 6,655

The Location property has an abnormal value when minimized. Use the RestoreBounds property when the window is minimized or maximized.

Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
    If Me.WindowState = FormWindowState.Normal Then
        My.Settings.FormSize = Size
        My.Settings.FormLoc = Location
    Else
        My.Settings.FormSize = RestoreBounds.Size
        My.Settings.FormLoc = RestoreBounds.Location
    End If
    If WindowState = FormWindowState.Maximized Then
        My.Settings.FormWindowStateMaximized = True
    Else
        My.Settings.FormWindowStateMaximized = False
    End If
End Sub

Darren Rose 311

Just found this function you can use to check if location is on screen or not - quick initial test seemed to work quite well - so this may potentially be a solution I could use.

Public Function IsOnScreen(ByVal RecLocation As System.Drawing.Point, ByVal RecSize As System.Drawing.Size, Optional ByVal MinPercentOnScreen As Double = 0.2) As Boolean
        Dim PixelsVisible As Double = 0
        Dim Rec As New System.Drawing.Rectangle(RecLocation, RecSize)

        For Each Scrn As Screen In Screen.AllScreens
            Dim r As System.Drawing.Rectangle = System.Drawing.Rectangle.Intersect(Rec, Scrn.WorkingArea)
            ' intersect rectangle with screen
            If r.Width <> 0 And r.Height <> 0 Then
                PixelsVisible += (r.Width * r.Height)
                ' tally visible pixels
            End If
        Next Scrn
        Return PixelsVisible >= (Rec.Width * Rec.Height) * MinPercentOnScreen
    End Function

e.g.

If IsOnScreen(My.Settings.FormLocation, My.Settings.FormSize) Then
            Size = My.Settings.FormSize
            Location = My.Settings.FormLocation
            If My.Settings.FormWindowStateMaximized = True Then
                WindowState = FormWindowState.Maximized
            End If
        End If

Darren Rose 311 Reputation points

2023-09-17T18:23:06.6066667+00:00

Thanks @KOZ6.0 - code amended
Anonymous

2023-09-17T18:29:21.1666667+00:00
Hi

OK, we have the interrupt. Please change the Test Sub to this and see what the location is after the disconnect (I have been unable to find any info on how to tell which DisplaySetting triggered the event we are monitoring yet)

Sub Test(sender As Object, e As EventArgs) Dim p As Point = Location Stop End Sub
Darren Rose 311 Reputation points

2023-09-17T18:58:59.52+00:00

see below
Anonymous

2023-09-17T19:12:40.4133333+00:00

Hi

I looked under my desk but can't see anything relevant :)
Darren Rose 311 Reputation points

2023-09-17T19:22:27.3333333+00:00

There "was" a screenshot when I posted - it disappeared!! ;)

X=26, Y=26
Anonymous

2023-09-17T19:30:53.43+00:00

Hi

Been there, got the T-shirt.

So, those are the coords of the Form, and the Form is not visible. So, what happens if you do a RestoreBounds.Location then? (I am fishing in the dark here)
Darren Rose 311 Reputation points

2023-09-17T20:04:04.54+00:00

If I do " Location = New Point(26, 26)" then the window comes up top left corner of main screen as I suppose you would expect.

I have been testing as well, and I think perhaps the better route here might be the IsOnScreen function I found and mentioned above which checks the location before restoring the window to ensure it is going to appear on a screen which is visible - from my testing so far this is working well
Anonymous

2023-09-17T20:23:43.39+00:00

Hi

Ah, I missed that post. Must have been cross posting? Yes, good idea. Let me know how you get on with it.
Darren Rose 311 Reputation points

2023-09-18T13:46:48.59+00:00

Seems to be working well, tested on two and three monitor setup, opening app on external screen, closing app to save position, disconnecting screen and then reopening app etc. Will post all my final code below
Darren Rose 311 Reputation points

2023-09-18T13:48:47.33+00:00

Seems to be working fine - tested on two and three monitor setup. Opening app on external screen, closing app to save settings. Disconnecting screen and reopening app which detects screen not connected so opens app on main screen. Will post final code etc below
Darren Rose 311 Reputation points

2023-09-18T13:58:18.1966667+00:00

Thanks @Les and @KOZ6.0 for pointing me in right direction

2 answers

Your answer

Anonymous

2023-09-17T15:53:32.04+00:00

Hi

Please explain a little more. I m assuming the 'normal' Form.Location and Form.Size are not what you are asking about - is that correct? If these ARE what you want to save and restore then it may be trivial.
Darren Rose 311 Reputation points

2023-09-17T15:56:03.67+00:00

I mean so that the next time the app is launched it will open in the last location and at the last size (and on the last monitor if still available) that the user had it
Anonymous

2023-09-17T16:29:23.2533333+00:00

Hi

As a starting point: Set up a couple of My.Settings. Add one lets say named FormSize as a Size type and the other lets say FormLoc as a Point type, see image below. (if you need further info on where to set these up, just ask) The names are arbitrary and you can name them as you see fit.

Each needs a default initial value. so lets say the FormSize is set to (500,400) and FormLoc is set to (100,100)

Once set up, in the Form code, add the following in the appropriate Load/Closing event handlers.

Option Strict On Option Explicit On Public Class Form1 Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing My.Settings.FormSize = Size My.Settings.FormLoc = Location End Sub Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load Size = My.Settings.FormSize Location = My.Settings.FormLoc End Sub End Class
Darren Rose 311 Reputation points

2023-09-17T16:43:57.0333333+00:00

Okay thanks, that works - until you close your app whilst on a second screen, disconnect the second screen and then open the app again, as it is opening the app off screen (on second screen which is no longer connected) so you can't see it - so we need some way of handling scenarios like that?
Anonymous

2023-09-17T16:52:16.59+00:00

Says you commented but doesn't let me see it. This is a post to jog this idiotic forum back to life.
Anonymous

2023-09-17T16:57:04.1+00:00

Hi

OK, that jogging worked and I can see your comment.

OK, this side of it is not something I have played with before. I will have a look to see what I can suggest, perhaps someone else will assist in the meantime.

BTW: there are a couple of ways that a second monitor can be used, such as shared in the sense that it forms one larger monitor, or as 2 separate monitors. Which are you using.
Darren Rose 311 Reputation points

2023-09-17T17:02:39.65+00:00

Thanks Les.

I was testing it as 2 separate monitors.

Also noticed doesn't remember if you have "maximized" the window - so suspect will need a third setting to save WindowState perhaps?
Anonymous

2023-09-17T17:25:30.9033333+00:00

Hi

You would need a third setting if you need to save/restore the state - perhaps a Boolean to indicate Maximized or not. If you want to include Minimized then a second one for that too.
Darren Rose 311 Reputation points

2023-09-17T17:50:42.1766667+00:00

Code amended to handle Maximized state - not worried about minimized

Edit: amended to fix abnormal value when minimized as per KOZ6.0 response below

Option Strict On Option Explicit On Public Class Form1 Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing If Me.WindowState = FormWindowState.Normal Then My.Settings.FormSize = Size My.Settings.FormLoc = Location Else My.Settings.FormSize = RestoreBounds.Size My.Settings.FormLoc = RestoreBounds.Location End If If WindowState = FormWindowState.Maximized Then My.Settings.FormWindowStateMaximized = True Else My.Settings.FormWindowStateMaximized = False End If End Sub Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load Size = My.Settings.FormSize Location = My.Settings.FormLoc If My.Settings.FormWindowStateMaximized = True Then WindowState = FormWindowState.Maximized End If End Sub End Class
Anonymous

2023-09-17T17:58:20.8266667+00:00

Hi

Unless someone else pops in to help, then you are the only source of a multiple monitor setup for testing. Would you try this adding these further lines of code to your project, run and see if you get a STOP when disconnecting second monitor. )see the code for the STOP location. This test is to discover if we can detect the second monitor disconnect.

add an Import at top of code:

Imports Microsoft.Win32

add an Event Handler in the Load Event for the Form:

AddHandler SystemEvents.DisplaySettingsChanged, AddressOf Test

add a Sub:

Sub Test(sender As Object, e As EventArgs) ' here is the STOP I need you to test for Stop End Sub
Darren Rose 311 Reputation points

2023-09-17T18:04:43.2766667+00:00

Yes that event triggers when disconnecting (and connecting) the second monitor
KOZ6.0 6,655 Reputation points

2023-09-17T18:13:59.07+00:00

The Location property has an abnormal value when minimized. Use the RestoreBounds property when the window is minimized or maximized.

Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing If Me.WindowState = FormWindowState.Normal Then My.Settings.FormSize = Size My.Settings.FormLoc = Location Else My.Settings.FormSize = RestoreBounds.Size My.Settings.FormLoc = RestoreBounds.Location End If If WindowState = FormWindowState.Maximized Then My.Settings.FormWindowStateMaximized = True Else My.Settings.FormWindowStateMaximized = False End If End Sub
Darren Rose 311 Reputation points

2023-09-17T18:15:53.3466667+00:00

Just found this function you can use to check if location is on screen or not - quick initial test seemed to work quite well - so this may potentially be a solution I could use.

Public Function IsOnScreen(ByVal RecLocation As System.Drawing.Point, ByVal RecSize As System.Drawing.Size, Optional ByVal MinPercentOnScreen As Double = 0.2) As Boolean Dim PixelsVisible As Double = 0 Dim Rec As New System.Drawing.Rectangle(RecLocation, RecSize) For Each Scrn As Screen In Screen.AllScreens Dim r As System.Drawing.Rectangle = System.Drawing.Rectangle.Intersect(Rec, Scrn.WorkingArea) ' intersect rectangle with screen If r.Width <> 0 And r.Height <> 0 Then PixelsVisible += (r.Width * r.Height) ' tally visible pixels End If Next Scrn Return PixelsVisible >= (Rec.Width * Rec.Height) * MinPercentOnScreen End Function

e.g.

If IsOnScreen(My.Settings.FormLocation, My.Settings.FormSize) Then Size = My.Settings.FormSize Location = My.Settings.FormLocation If My.Settings.FormWindowStateMaximized = True Then WindowState = FormWindowState.Maximized End If End If
Darren Rose 311 Reputation points

2023-09-17T18:23:06.6066667+00:00

Thanks @KOZ6.0 - code amended
Anonymous

2023-09-17T18:29:21.1666667+00:00

Hi

OK, we have the interrupt. Please change the Test Sub to this and see what the location is after the disconnect (I have been unable to find any info on how to tell which DisplaySetting triggered the event we are monitoring yet)

Sub Test(sender As Object, e As EventArgs) Dim p As Point = Location Stop End Sub
Darren Rose 311 Reputation points

2023-09-17T18:58:59.52+00:00

see below
Anonymous

2023-09-17T19:12:40.4133333+00:00

Hi

I looked under my desk but can't see anything relevant :)
Darren Rose 311 Reputation points

2023-09-17T19:22:27.3333333+00:00

There "was" a screenshot when I posted - it disappeared!! ;)

X=26, Y=26
Anonymous

2023-09-17T19:30:53.43+00:00

Hi

Been there, got the T-shirt.

So, those are the coords of the Form, and the Form is not visible. So, what happens if you do a RestoreBounds.Location then? (I am fishing in the dark here)
Darren Rose 311 Reputation points

2023-09-17T20:04:04.54+00:00

If I do " Location = New Point(26, 26)" then the window comes up top left corner of main screen as I suppose you would expect.

I have been testing as well, and I think perhaps the better route here might be the IsOnScreen function I found and mentioned above which checks the location before restoring the window to ensure it is going to appear on a screen which is visible - from my testing so far this is working well
Anonymous

2023-09-17T20:23:43.39+00:00

Hi

Ah, I missed that post. Must have been cross posting? Yes, good idea. Let me know how you get on with it.
Darren Rose 311 Reputation points

2023-09-18T13:46:48.59+00:00

Seems to be working well, tested on two and three monitor setup, opening app on external screen, closing app to save position, disconnecting screen and then reopening app etc. Will post all my final code below
Darren Rose 311 Reputation points

2023-09-18T13:48:47.33+00:00

Seems to be working fine - tested on two and three monitor setup. Opening app on external screen, closing app to save settings. Disconnecting screen and reopening app which detects screen not connected so opens app on main screen. Will post final code etc below
Darren Rose 311 Reputation points

2023-09-18T13:58:18.1966667+00:00

Thanks @Les and @KOZ6.0 for pointing me in right direction

Answer 1

Dewayne Basnett 1,381

To answer the "...which covers issues like second monitor then being disconnected..." question.

I've had this issue. All of our production Form apps have a common splash screen that always shows. On that screen I put a button to fix the application not being visible when started. The button sets a boolean that the main form checks in the Load event, and if true it sets / resets, the location.

The user can adjust the monitor for the app window immediately after starting by,

Win + Shift + Left Arrow: move a window to the monitor on the left

Win + Shift+Right Arrow: move a window to the monitor on the right

Darren Rose 311 Reputation points

2023-09-18T15:39:46.4266667+00:00

Good idea, and thanks for the shortcut keys - didn't know those

Answer 2

Final solution which seems to work for me:

My.Settings

2023-09-18_14-49-48

Code

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        ' Restore Form Size, Location and WindowState - override by holding down Ctrl+Shift when opening app
        If (Control.ModifierKeys And Keys.Shift) = 0 Then
            If IsOnScreen(My.Settings.FormLocation, My.Settings.FormSize) Then
                Size = My.Settings.FormSize
                Location = My.Settings.FormLocation
                WindowState = My.Settings.FormWindowState
            Else
                Size = My.Settings.FormSize
                WindowState = My.Settings.FormWindowState
            End If
        End If

End Sub

Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing

        ' Save Form Size, Location and WindowState
        ' Save Size and Location (or RestoreBounds Size and Location if Minimized or Maximized)
        If Me.WindowState = FormWindowState.Normal Then
            My.Settings.FormSize = Size
            My.Settings.FormLocation = Location
        Else
            My.Settings.FormSize = RestoreBounds.Size
            My.Settings.FormLocation = RestoreBounds.Location
        End If
        ' Only save the WindowState if Normal or Maximized
        If Me.WindowState = FormWindowState.Normal Or Me.WindowState = FormWindowState.Maximized Then
            My.Settings.FormWindowState = WindowState
        Else
            My.Settings.FormWindowState = FormWindowState.Normal
        End If

        ' save settings
        My.Settings.Save()

End Sub

Public Function IsOnScreen(ByVal RecLocation As System.Drawing.Point, ByVal RecSize As System.Drawing.Size, Optional ByVal MinPercentOnScreen As Double = 0.2) As Boolean
        Dim PixelsVisible As Double = 0
        Dim Rec As New System.Drawing.Rectangle(RecLocation, RecSize)

        For Each Scrn As Screen In Screen.AllScreens
            Dim r As System.Drawing.Rectangle = System.Drawing.Rectangle.Intersect(Rec, Scrn.WorkingArea)
            ' intersect rectangle with screen
            If r.Width <> 0 And r.Height <> 0 Then
                PixelsVisible += (r.Width * r.Height)
                ' tally visible pixels
            End If
        Next Scrn
        Return PixelsVisible >= (Rec.Width * Rec.Height) * MinPercentOnScreen
End Function

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Function to save/restore last used form size/position with multiple monitor support

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