Skip to content

DOCINFRA-2341_merged_using_automation #1293

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 5 commits into from
Aug 5, 2025
Merged

DOCINFRA-2341_merged_using_automation #1293

Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
7887cfa
Updated the MDI Child Form flicker prevention documentation with nece…
Karthick-Arjunan Aug 1, 2025
10fc103
Updated
Karthick-Arjunan Aug 1, 2025
1048c8d
Updated
Karthick-Arjunan Aug 1, 2025
01036e3
Update How-to-avoid-flickering-while-creating-MDI-child-form.md
Karthick-Arjunan Aug 5, 2025
b37a970
Merge pull request #1291 from syncfusion-content/963841-hotfix
durga-muthu Aug 5, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 17 additions & 10 deletions ...g-Manager/FAQ/MDIChild/How-to-avoid-flickering-while-creating-MDI-child-form.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,56 +1,63 @@
---
layout: post
title: How to avoid flickering while creating MDI child form | WindowsForms | Syncfusion®
description: How to avoid flickering while creating MDI child form
title: How to avoid flickering while creating MDI child form | Syncfusion®
description: Learn how to avoid flickering when creating and docking MDI child forms in Windows Forms applications using Syncfusion Docking Manager.
platform: windowsforms
control: DockingManager
documentation: ug
---

# How to avoid flickering while creating MDI child form?

Flickering can be avoided by calling the below methods.
Flickering can occur when creating and docking MDI child forms due to frequent redraws and layout updates. This can be avoided by calling the below methods.

* LockHostFormUpdate
* UnLockHostFormUpdate
* UnlockHostFormUpdate

The LockHostFormUpdate and UnLockHostFormUpdate methods are used to lock and unlock the host form's updates respectively. These methods helps in avoiding flickering while creating an MDI child form. These methods can be used in the following way.
The LockHostFormUpdate and UnlockHostFormUpdate methods are used to temporarily suspend and resume UI updates on the host form. This prevent flickering while creating an MDI child form.

**When to Use These Methods**

Use LockHostFormUpdate() before performing any docking or layout operations, and UnlockHostFormUpdate() after the operations are complete. This ensures that the host form does not redraw multiple times during the process, which is the primary cause of flickering. These methods can be used in the following way.

{% tabs %}

{% highlight C# %}

//To avoid flickering

//Lock the host form to prevent flickering during layout changes
this.dockingManager1.LockHostFormUpdate();

//Dock and configure the MDI child form
this.dockingManager1.DockControl(form, this, Syncfusion.Windows.Forms.Tools.DockingStyle.Right, 0);

this.dockingManager1.SetAsMDIChild(form, true);

this.dockingManager1.SetControlSize(form, size);

//Unlock the host form to resume UI updates
this.dockingManager1.UnlockHostFormUpdate();

{% endhighlight %}


{% highlight VB %}


'To avoid flickering

'Lock the host form to prevent flickering during layout changes
Me.dockingManager1.LockHostFormUpdate()

'Dock and configure the MDI child form
Me.dockingManager1.DockControl(form, Me, Syncfusion.Windows.Forms.Tools.DockingStyle.Right, 0)

Me.dockingManager1.SetAsMDIChild(form, True)

Me.dockingManager1.SetControlSize(form, size)

'Unlock the host form to resume UI updates
Me.dockingManager1.UnlockHostFormUpdate()

{% endhighlight %}

{% endtabs %}

When multiple UI changes happen rapidly (like docking, resizing, or adding controls), the form may redraw several times, causing flickering. By locking updates during these operations, allowing the form to redraw only once, after all changes are complete.