How do I suspend painting for a control and its children

Question

I have a control which I have to make large modifications to   I d like to completely prevent it from redrawing while I do that - SuspendLayout and ResumeLayout aren t enough   How do I suspend painting for a control and its children

User · Answer

I usually use a little modified version of ngLink's answer.

public class MyControl : Control
{
    private int suspendCounter = 0;

    private void SuspendDrawing()
    {
        if(suspendCounter == 0) 
            SendMessage(this.Handle, WM_SETREDRAW, false, 0);
        suspendCounter++;
    }

    private void ResumeDrawing()
    {
        suspendCounter--; 
        if(suspendCounter == 0) 
        {
            SendMessage(this.Handle, WM_SETREDRAW, true, 0);
            this.Refresh();
        }
    }
}

This allows suspend/resume calls to be nested. You must make sure to match each SuspendDrawing with a ResumeDrawing. Hence, it wouldn't probably be a good idea to make them public.

User · Answer

Based on ng5000 s answer  I like using this extension            region Suspend          DllImport  user32 dll            private static extern int SendMessage IntPtr hWnd  Int32 wMsg  bool wParam  Int32 lParam           private const int WM SETREDRAW   11          public static IDisposable BeginSuspendlock this Control ctrl                        return new suspender ctrl                     private class suspender   IDisposable                       private Control  ctrl              public suspender Control ctrl                                this  ctrl   ctrl                  SendMessage this  ctrl Handle  WM SETREDRAW  false  0                             public void Dispose                                 SendMessage this  ctrl Handle  WM SETREDRAW  true  0                   this  ctrl Refresh                                     endregion   Use   using  this BeginSuspendlock            update GUI

User · Answer

The following is the same solution of ng5000 but doesn t use P Invoke   public static class SuspendUpdate       private const int WM SETREDRAW   0x000B       public static void Suspend Control control                Message msgSuspendUpdate   Message Create control Handle  WM SETREDRAW  IntPtr Zero              IntPtr Zero            NativeWindow window   NativeWindow FromHandle control Handle           window DefWndProc ref msgSuspendUpdate              public static void Resume Control control                   Create a C  true  boolean as an IntPtr         IntPtr wparam   new IntPtr 1           Message msgResumeUpdate   Message Create control Handle  WM SETREDRAW  wparam              IntPtr Zero            NativeWindow window   NativeWindow FromHandle control Handle           window DefWndProc ref msgResumeUpdate            control Invalidate

User · Answer

To help with not forgetting to reenable drawing   public static void SuspendDrawing Control control  Action action        SendMessage control Handle  WM SETREDRAW  false  0       action        SendMessage control Handle  WM SETREDRAW  true  0       control Refresh        usage   SuspendDrawing myControl       gt        somemethod

User · Answer

A nice solution without using interop   As always  simply enable DoubleBuffered true on your CustomControl   Then  if you have any containers like FlowLayoutPanel or TableLayoutPanel  derive a class from each of these types and in the constructors  enable double buffering   Now  simply use your derived Containers instead of the Windows Forms Containers   class TableLayoutPanel   System Windows Forms TableLayoutPanel       public TableLayoutPanel                 DoubleBuffered   true           class FlowLayoutPanel   System Windows Forms FlowLayoutPanel       public FlowLayoutPanel                 DoubleBuffered   true

User · Answer

I know this is an old question  already answered  but here is my take on this  I refactored the suspension of updates into an IDisposable - that way I can enclose the statements I want to run in a using statement   class SuspendDrawingUpdate   IDisposable       private const int WM SETREDRAW   0x000B      private readonly Control  control      private readonly NativeWindow  window       public SuspendDrawingUpdate Control control                 control   control           var msgSuspendUpdate   Message Create  control Handle  WM SETREDRAW  IntPtr Zero  IntPtr Zero             window   NativeWindow FromHandle  control Handle            window DefWndProc ref msgSuspendUpdate              public void Dispose                 var wparam   new IntPtr 1       Create a C  true  boolean as an IntPtr         var msgResumeUpdate   Message Create  control Handle  WM SETREDRAW  wparam  IntPtr Zero             window DefWndProc ref msgResumeUpdate             control Invalidate

User · Answer

Here is a combination of ceztko s and ng5000 s to bring a VB extensions version that doesn t use pinvoke  Imports System Runtime CompilerServices  Module ControlExtensions  Dim WM SETREDRAW As Integer   11       lt summary gt      A stronger  SuspendLayout  completely holds the controls painting until ResumePaint is called      lt  summary gt       lt param name  ctrl  gt  lt  param gt       lt remarks gt  lt  remarks gt   lt Extension   gt  Public Sub SuspendPaint ByVal ctrl As Windows Forms Control       Dim msgSuspendUpdate As Windows Forms Message   Windows Forms Message Create ctrl Handle  WM SETREDRAW  System IntPtr Zero  System IntPtr Zero       Dim window As Windows Forms NativeWindow   Windows Forms NativeWindow FromHandle ctrl Handle       window DefWndProc msgSuspendUpdate   End Sub       lt summary gt      Resume from SuspendPaint method      lt  summary gt       lt param name  ctrl  gt  lt  param gt       lt remarks gt  lt  remarks gt   lt Extension   gt  Public Sub ResumePaint ByVal ctrl As Windows Forms Control       Dim wparam As New System IntPtr 1      Dim msgResumeUpdate As Windows Forms Message   Windows Forms Message Create ctrl Handle  WM SETREDRAW  wparam  System IntPtr Zero       Dim window As Windows Forms NativeWindow   Windows Forms NativeWindow FromHandle ctrl Handle       window DefWndProc msgResumeUpdate       ctrl Invalidate    End Sub  End Module

User · Answer

I know this is an old question  already answered  but here is my take on this  I refactored the suspension of updates into an IDisposable - that way I can enclose the statements I want to run in a using statement   class SuspendDrawingUpdate   IDisposable       private const int WM SETREDRAW   0x000B      private readonly Control  control      private readonly NativeWindow  window       public SuspendDrawingUpdate Control control                 control   control           var msgSuspendUpdate   Message Create  control Handle  WM SETREDRAW  IntPtr Zero  IntPtr Zero             window   NativeWindow FromHandle  control Handle            window DefWndProc ref msgSuspendUpdate              public void Dispose                 var wparam   new IntPtr 1       Create a C  true  boolean as an IntPtr         var msgResumeUpdate   Message Create  control Handle  WM SETREDRAW  wparam  IntPtr Zero             window DefWndProc ref msgResumeUpdate             control Invalidate

User · Answer

Based on ng5000 s answer  I like using this extension            region Suspend          DllImport  user32 dll            private static extern int SendMessage IntPtr hWnd  Int32 wMsg  bool wParam  Int32 lParam           private const int WM SETREDRAW   11          public static IDisposable BeginSuspendlock this Control ctrl                        return new suspender ctrl                     private class suspender   IDisposable                       private Control  ctrl              public suspender Control ctrl                                this  ctrl   ctrl                  SendMessage this  ctrl Handle  WM SETREDRAW  false  0                             public void Dispose                                 SendMessage this  ctrl Handle  WM SETREDRAW  true  0                   this  ctrl Refresh                                     endregion   Use   using  this BeginSuspendlock            update GUI

User · Answer

This is even simpler  and perhaps hacky - as I can see a lot of GDI muscle on this thread  and is obviously only a good fit for certain scenarios  YMMV In my scenario  I use what I ll refer to as a  quot Parent quot  UserControl - and during the Load event  I simply remove the control-to-be-manipulated from the Parent s  Controls collection  and the Parent s OnPaint takes care of completely painting the child control in whatever special way   fully taking the child s paint capabilities offline  Now  I hand off my child paint routine to an extension method based off this concept from Mike Gold for printing windows forms  Here I m needing a sub-set of labels to render perpendicular to the layout   Then  I exempt the child control from being painted  with this code in the ParentUserControl Load event handler  Private Sub ParentUserControl Load sender As Object  e As EventArgs  Handles MyBase Load     SetStyle ControlStyles UserPaint  True      SetStyle ControlStyles AllPaintingInWmPaint  True        exempt this control from standard painting       Me Controls Remove Me HostedControlToBeRotated   End Sub  Then  in the same ParentUserControl  we paint the control-to-be-manipulated from the ground up  Protected Overrides Sub OnPaint e As PaintEventArgs       here  we will custom paint the HostedControlToBeRotated instance          twist rendering mode 90 counter clockwise  and shift rendering over to right-most end      e Graphics SmoothingMode   Drawing2D SmoothingMode AntiAlias     e Graphics TranslateTransform Me Width - Me HostedControlToBeRotated Height  Me Height      e Graphics RotateTransform -90      MyCompany Forms CustomGDI DrawControlAndChildren Me HostedControlToBeRotated  e Graphics       e Graphics ResetTransform       e Graphics Dispose        GC Collect   End Sub  Once you host the ParentUserControl somewhere  e g  a Windows Form - I m finding that my Visual Studio 2015 renders the form correctly at Design Time as well as runtime   Now  since my particular manipulation rotates the child control 90 degrees  I m sure all the hot spots and interactivity has been destroyed in that region - but  the problem I was solving was all for a package label that needed to preview and print  which worked out fine for me  If there are ways to reintroduce the hot spots and control-ness to my purposely orphaned control - I d love to learn about that someday  not for this scenario  of course  but   just to learn   Of course  WPF supports such craziness OOTB   but   hey   WinForms is so much fun still  amiright

User · Answer

At my previous job we struggled with getting our rich UI app to paint instantly and smoothly   We were using standard  Net controls  custom controls and devexpress controls   After a lot of googling and reflector usage I came across the WM SETREDRAW win32 message   This really stops controls drawing whilst you update them and can be applied  IIRC to the parent containing panel   This is a very very simple class demonstrating how to use this message   class DrawingControl        DllImport  user32 dll        public static extern int SendMessage IntPtr hWnd  Int32 wMsg  bool wParam  Int32 lParam        private const int WM SETREDRAW   11        public static void SuspendDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  false  0              public static void ResumeDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  true  0           parent Refresh              There are fuller discussions on this - google for C  and WM SETREDRAW  e g   C  Jitter  Suspending Layouts  And to whom it may concern  this is similar example in VB   Public Module Extensions      lt DllImport  user32 dll   gt      Private Function SendMessage ByVal hWnd As IntPtr  ByVal Msg As Integer  ByVal wParam As Boolean  ByVal lParam As IntPtr  As Integer     End Function      Private Const WM SETREDRAW As Integer   11        Extension methods for Control      lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control  ByVal Redraw As Boolean          SendMessage Target Handle  WM SETREDRAW  True  0          If Redraw Then             Target Refresh           End If     End Sub       lt Extension   gt      Public Sub SuspendDrawing ByVal Target As Control          SendMessage Target Handle  WM SETREDRAW  False  0      End Sub       lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control          ResumeDrawing Target  True      End Sub End Module

User · Answer

Or just use Control SuspendLayout   and Control ResumeLayout

User · Answer

At my previous job we struggled with getting our rich UI app to paint instantly and smoothly   We were using standard  Net controls  custom controls and devexpress controls   After a lot of googling and reflector usage I came across the WM SETREDRAW win32 message   This really stops controls drawing whilst you update them and can be applied  IIRC to the parent containing panel   This is a very very simple class demonstrating how to use this message   class DrawingControl        DllImport  user32 dll        public static extern int SendMessage IntPtr hWnd  Int32 wMsg  bool wParam  Int32 lParam        private const int WM SETREDRAW   11        public static void SuspendDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  false  0              public static void ResumeDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  true  0           parent Refresh              There are fuller discussions on this - google for C  and WM SETREDRAW  e g   C  Jitter  Suspending Layouts  And to whom it may concern  this is similar example in VB   Public Module Extensions      lt DllImport  user32 dll   gt      Private Function SendMessage ByVal hWnd As IntPtr  ByVal Msg As Integer  ByVal wParam As Boolean  ByVal lParam As IntPtr  As Integer     End Function      Private Const WM SETREDRAW As Integer   11        Extension methods for Control      lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control  ByVal Redraw As Boolean          SendMessage Target Handle  WM SETREDRAW  True  0          If Redraw Then             Target Refresh           End If     End Sub       lt Extension   gt      Public Sub SuspendDrawing ByVal Target As Control          SendMessage Target Handle  WM SETREDRAW  False  0      End Sub       lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control          ResumeDrawing Target  True      End Sub End Module

User · Answer

At my previous job we struggled with getting our rich UI app to paint instantly and smoothly   We were using standard  Net controls  custom controls and devexpress controls   After a lot of googling and reflector usage I came across the WM SETREDRAW win32 message   This really stops controls drawing whilst you update them and can be applied  IIRC to the parent containing panel   This is a very very simple class demonstrating how to use this message   class DrawingControl        DllImport  user32 dll        public static extern int SendMessage IntPtr hWnd  Int32 wMsg  bool wParam  Int32 lParam        private const int WM SETREDRAW   11        public static void SuspendDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  false  0              public static void ResumeDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  true  0           parent Refresh              There are fuller discussions on this - google for C  and WM SETREDRAW  e g   C  Jitter  Suspending Layouts  And to whom it may concern  this is similar example in VB   Public Module Extensions      lt DllImport  user32 dll   gt      Private Function SendMessage ByVal hWnd As IntPtr  ByVal Msg As Integer  ByVal wParam As Boolean  ByVal lParam As IntPtr  As Integer     End Function      Private Const WM SETREDRAW As Integer   11        Extension methods for Control      lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control  ByVal Redraw As Boolean          SendMessage Target Handle  WM SETREDRAW  True  0          If Redraw Then             Target Refresh           End If     End Sub       lt Extension   gt      Public Sub SuspendDrawing ByVal Target As Control          SendMessage Target Handle  WM SETREDRAW  False  0      End Sub       lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control          ResumeDrawing Target  True      End Sub End Module

User · Answer

Or just use Control SuspendLayout   and Control ResumeLayout

User · Answer

This is even simpler  and perhaps hacky - as I can see a lot of GDI muscle on this thread  and is obviously only a good fit for certain scenarios  YMMV In my scenario  I use what I ll refer to as a  quot Parent quot  UserControl - and during the Load event  I simply remove the control-to-be-manipulated from the Parent s  Controls collection  and the Parent s OnPaint takes care of completely painting the child control in whatever special way   fully taking the child s paint capabilities offline  Now  I hand off my child paint routine to an extension method based off this concept from Mike Gold for printing windows forms  Here I m needing a sub-set of labels to render perpendicular to the layout   Then  I exempt the child control from being painted  with this code in the ParentUserControl Load event handler  Private Sub ParentUserControl Load sender As Object  e As EventArgs  Handles MyBase Load     SetStyle ControlStyles UserPaint  True      SetStyle ControlStyles AllPaintingInWmPaint  True        exempt this control from standard painting       Me Controls Remove Me HostedControlToBeRotated   End Sub  Then  in the same ParentUserControl  we paint the control-to-be-manipulated from the ground up  Protected Overrides Sub OnPaint e As PaintEventArgs       here  we will custom paint the HostedControlToBeRotated instance          twist rendering mode 90 counter clockwise  and shift rendering over to right-most end      e Graphics SmoothingMode   Drawing2D SmoothingMode AntiAlias     e Graphics TranslateTransform Me Width - Me HostedControlToBeRotated Height  Me Height      e Graphics RotateTransform -90      MyCompany Forms CustomGDI DrawControlAndChildren Me HostedControlToBeRotated  e Graphics       e Graphics ResetTransform       e Graphics Dispose        GC Collect   End Sub  Once you host the ParentUserControl somewhere  e g  a Windows Form - I m finding that my Visual Studio 2015 renders the form correctly at Design Time as well as runtime   Now  since my particular manipulation rotates the child control 90 degrees  I m sure all the hot spots and interactivity has been destroyed in that region - but  the problem I was solving was all for a package label that needed to preview and print  which worked out fine for me  If there are ways to reintroduce the hot spots and control-ness to my purposely orphaned control - I d love to learn about that someday  not for this scenario  of course  but   just to learn   Of course  WPF supports such craziness OOTB   but   hey   WinForms is so much fun still  amiright

User · Answer

To help with not forgetting to reenable drawing   public static void SuspendDrawing Control control  Action action        SendMessage control Handle  WM SETREDRAW  false  0       action        SendMessage control Handle  WM SETREDRAW  true  0       control Refresh        usage   SuspendDrawing myControl       gt        somemethod

User · Answer

The following is the same solution of ng5000 but doesn t use P Invoke   public static class SuspendUpdate       private const int WM SETREDRAW   0x000B       public static void Suspend Control control                Message msgSuspendUpdate   Message Create control Handle  WM SETREDRAW  IntPtr Zero              IntPtr Zero            NativeWindow window   NativeWindow FromHandle control Handle           window DefWndProc ref msgSuspendUpdate              public static void Resume Control control                   Create a C  true  boolean as an IntPtr         IntPtr wparam   new IntPtr 1           Message msgResumeUpdate   Message Create control Handle  WM SETREDRAW  wparam              IntPtr Zero            NativeWindow window   NativeWindow FromHandle control Handle           window DefWndProc ref msgResumeUpdate            control Invalidate

User · Answer

I usually use a little modified version of ngLink's answer.

public class MyControl : Control
{
    private int suspendCounter = 0;

    private void SuspendDrawing()
    {
        if(suspendCounter == 0) 
            SendMessage(this.Handle, WM_SETREDRAW, false, 0);
        suspendCounter++;
    }

    private void ResumeDrawing()
    {
        suspendCounter--; 
        if(suspendCounter == 0) 
        {
            SendMessage(this.Handle, WM_SETREDRAW, true, 0);
            this.Refresh();
        }
    }
}

This allows suspend/resume calls to be nested. You must make sure to match each SuspendDrawing with a ResumeDrawing. Hence, it wouldn't probably be a good idea to make them public.

User · Answer

Here is a combination of ceztko s and ng5000 s to bring a VB extensions version that doesn t use pinvoke  Imports System Runtime CompilerServices  Module ControlExtensions  Dim WM SETREDRAW As Integer   11       lt summary gt      A stronger  SuspendLayout  completely holds the controls painting until ResumePaint is called      lt  summary gt       lt param name  ctrl  gt  lt  param gt       lt remarks gt  lt  remarks gt   lt Extension   gt  Public Sub SuspendPaint ByVal ctrl As Windows Forms Control       Dim msgSuspendUpdate As Windows Forms Message   Windows Forms Message Create ctrl Handle  WM SETREDRAW  System IntPtr Zero  System IntPtr Zero       Dim window As Windows Forms NativeWindow   Windows Forms NativeWindow FromHandle ctrl Handle       window DefWndProc msgSuspendUpdate   End Sub       lt summary gt      Resume from SuspendPaint method      lt  summary gt       lt param name  ctrl  gt  lt  param gt       lt remarks gt  lt  remarks gt   lt Extension   gt  Public Sub ResumePaint ByVal ctrl As Windows Forms Control       Dim wparam As New System IntPtr 1      Dim msgResumeUpdate As Windows Forms Message   Windows Forms Message Create ctrl Handle  WM SETREDRAW  wparam  System IntPtr Zero       Dim window As Windows Forms NativeWindow   Windows Forms NativeWindow FromHandle ctrl Handle       window DefWndProc msgResumeUpdate       ctrl Invalidate    End Sub  End Module

User · Answer

A nice solution without using interop   As always  simply enable DoubleBuffered true on your CustomControl   Then  if you have any containers like FlowLayoutPanel or TableLayoutPanel  derive a class from each of these types and in the constructors  enable double buffering   Now  simply use your derived Containers instead of the Windows Forms Containers   class TableLayoutPanel   System Windows Forms TableLayoutPanel       public TableLayoutPanel                 DoubleBuffered   true           class FlowLayoutPanel   System Windows Forms FlowLayoutPanel       public FlowLayoutPanel                 DoubleBuffered   true

User · Answer

At my previous job we struggled with getting our rich UI app to paint instantly and smoothly   We were using standard  Net controls  custom controls and devexpress controls   After a lot of googling and reflector usage I came across the WM SETREDRAW win32 message   This really stops controls drawing whilst you update them and can be applied  IIRC to the parent containing panel   This is a very very simple class demonstrating how to use this message   class DrawingControl        DllImport  user32 dll        public static extern int SendMessage IntPtr hWnd  Int32 wMsg  bool wParam  Int32 lParam        private const int WM SETREDRAW   11        public static void SuspendDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  false  0              public static void ResumeDrawing  Control parent                 SendMessage parent Handle  WM SETREDRAW  true  0           parent Refresh              There are fuller discussions on this - google for C  and WM SETREDRAW  e g   C  Jitter  Suspending Layouts  And to whom it may concern  this is similar example in VB   Public Module Extensions      lt DllImport  user32 dll   gt      Private Function SendMessage ByVal hWnd As IntPtr  ByVal Msg As Integer  ByVal wParam As Boolean  ByVal lParam As IntPtr  As Integer     End Function      Private Const WM SETREDRAW As Integer   11        Extension methods for Control      lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control  ByVal Redraw As Boolean          SendMessage Target Handle  WM SETREDRAW  True  0          If Redraw Then             Target Refresh           End If     End Sub       lt Extension   gt      Public Sub SuspendDrawing ByVal Target As Control          SendMessage Target Handle  WM SETREDRAW  False  0      End Sub       lt Extension   gt      Public Sub ResumeDrawing ByVal Target As Control          ResumeDrawing Target  True      End Sub End Module

[c#] How do I suspend painting for a control and its children?

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