Sleep command problem

[MACH4]

Hi all,
First post!
Learning vb.net

the following is the button handler code:

TextBox1.text = "Sleeping"
Thread.Sleep(500)
TextBox1.text = "Done!"

Why is the first line being ignored?

TextBox stays empty until after Sleep() then shows "Done" message...

Thanks for any help!

[misza]

Hi all,
First post!
Learning vb.net

the following is the button handler code:

TextBox1.text = "Sleeping"
Thread.Sleep(500)
TextBox1.text = "Done!"

Why is the first line being ignored?

TextBox stays empty until after Sleep() then shows "Done" message...

Thanks for any help!

Hi,

Try calling Application.DoEvents before the sleep line.

The answer to "why": for my (limited still) knowledge, it would have something to do with form events (paint, etc) - the real time they're being executed; pls someone elaborate on this;)

hope this helps
M.

[MACH4]

Hi M,

Thanks for replying!
Yes your additional line does work thanks!

Must admit I haven't used the Sleep command much before and my default language is Assembler, which prompted me to check it out further in that language.

It seems that Do.Events (in this particular case) is equivalent to the UpdateWindow api function call. Using InvalidateRect to force a re-paint didn't work...

MACH4

[MACH4]

Hi M,

Just to qualify my last message statement, I've just concocted the following code using the win32 api "UpdateWindow"...

Declare Auto Function UpdateWindow Lib "user32"(ByVal hwnd As IntPtr) As IntPtr


' Button handler code

Dim ptr As IntPtr = Handle

TextBox1.Text = "Waiting"
UpdateWindow(ptr)
Thread.Sleep(500)
TextBox1.Text = "Done!"

As you can see, its a bit clumbersome for a VB.NET application but seems explain (at least partially) what Do.Events is performing!

Thanks!

MACH4

[Plater]

do events just tells the program to process the windows messages before continuing execution.
Telling your textbox to .Update() would accomplish the text being updated as well.

[MACH4]

Hi Plater,

Yes, thanks or the info! I'm guilty of looking too deep!

One thing that is becoming obvious with .NET is that if some code is more than 5 lines long, then there must exist an easier way! lol

MACH4