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…

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.