C#: Does ResumeLayout(true) do the same as ResumeLayout(false) + PerformLayout()?

Question

I have looked at the generated designer code of Forms and UserControls, and in the InitializeComponent() method they always start with

    this.SuspendLayout();

and end with

    this.ResumeLayout(false);
    this.PerformLayout();

But from what I can see in the msdn documentation of those methods, wouldn't ending with

    this.ResumeLayout(true); // Or just this.ResumeLayout()

do the exact same thing? Or am I missing something here?

Asking because I will be adding a bunch of controls in a different method, and thought I should do the suspend-resume routine to be nice and efficient. But can't figure out what the reason for those two method calls are when you can seemingly just use one...

Hush

Answer 1

Using reflector:

this.ResumeLayout() is equal to this.ResumeLayout(true)

But

this.ResumeLayout(true) is not equal to this.ResumeLayout(false) + this.PerformLayout()

Reason:
When ResumeLayout is called with false, there is a control collection that is looped through and the LayoutEngine calls InitLayout on each of the controls in the layout.

Thormora

So to get the correct behaviour, I guess I would have to call them both? – Hush

Unfortunately it looks that way – Thormora

Alright. Well, thanks for the info then :) I must say that I don't quite understand the point of ResumeLayout(true) then, but it probably has its reason. – Hush

I'd like to request somebody volunteer a common or typical scenario where a "true" parameter will produce different behavior or results than a "false" parameter. Thanks. – Dercy

Answer 2

SuspendLayout

When adding several controls to a parent control, it is recommended that you call the SuspendLayout method before initializing the controls to be added. After adding the controls to the parent control, call the ResumeLayout method. This will increase the performance of applications with many controls.

PerformLayout

It forces the control to apply layout logic to all its child controls. If the SuspendLayout method was called before calling the PerformLayout method, the Layout event is suppressed. The layout event can be suppressed using the SuspendLayout and ResumeLayout methods.

MSDN Link - PerformLayout Method

Fadden

That makes sense, but what about ResumeLayout? Does calling ResumeLayout(true) perform the same work as calling ResumeLayout(false) and PerformLayout()? – Hush

I think this link will answer your question - ddj.com/architect/184405892 – Fadden