I have a Picturebox that has an image displayed inside. Through code,
I was able to have the "whole image" display in it without distortion.
(Like a "Fit All" in most any image viewer program)

Now, when the Picturebox gets resized by the user, I want the image to
recalculate and display as "Fit All" again.

So I have code in my SizeChanged event of the picturebox. When the
"size changed", it does it's calculation, and displays properly.

It works, but there is a problem: If the user drags the Picturebox
window larger or smaller, the SizeChanged event fires many times per
second. This causes alot of sluggishness in the app when trying to
display the image.

Is there anyway that i can have the SizeChanged event fire ONCE when
i'm done resizing the picturebox?

(By the way, the picturebox gets resized indirectly. It's dock is set
to Fill. When the interface "Next" to it gets resized, the Picturebox
naturally will resize accordingly)

Thanks for all your help!

John

Hi John,

when you run you code:

[quoted text, click to view]

the first time you see the messagebox pop up is because the form is
initialized, but after that the event normal only fires if you let go the
form border, so at the end of the SizeChanged event.

hth
Greetz Peter

--
Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning.

"johnb41" <orders@informatik.com> schreef in bericht
news:1117457542.581437.123130@z14g2000cwz.googlegroups.com...
[quoted text, click to view]

"johnb41"

[quoted text, click to view]
\\\
Static OldSize As Size
If Not OldSize.Equals(MeControl.Size) Then
....procedure
End If
///
I hope this helps,

Cor

"johnb41" <orders@informatik.com> schrieb:
[quoted text, click to view]

If you are experiencing a flicker, you could enable double buffering for the
picturebox control. To do so, create a class that inherits from
'System.Windows.Forms.PictureBox' and provides the constructor shown in the
listing below:

\\\
Public Sub New()
Me.SetStyle( _
ControlStyles.ResizeRedraw Or _
ControlStyles.DoubleBuffer Or _
ControlStyles.AllPaintingInWmPaint, _
True _
)
Me.UpdateStyles()
End Sub
///

Then you use your custom picturebox control instead of the standard Windows
Forms picturebox.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

Peter,

It's actually a Panel that I have the SizeChanged event attached to.
This is so the I get scrollbars when the image is larger than the
Panel.

If it's not any trouble, could you post some sample code that makes the
event fire only once? I just did a sample test on resizing a plain
form:

Private Sub Form1_SizeChanged(...) Handles MyBase.SizeChanged
MessageBox.Show("Size Changed!")
End Sub

The form won't even resize because the messagebox pops up immediately.
If I could get the messagebox to show up after finishing the resize,
that would be awesome. I could then adapt it to my real app.

Thanks!
John

Thanks for the reply. You make it seem obvious! Could you describe
more of what you mean, as it's very unclear to me. Thanks!

John

I gotta leave and do family stuff on this Memorial Day, so i'll only
post this quick message:

For me, the SizeChanged event seems to keep firing again and again,
until I let go of the mouse. This is in my real app, not the sample
one w/ the messagebox. For example, the image constantly tries to
redraw its self until I let go of the mouse.

I'll have to do more testing, and then play w/ Cor and herfried's
suggestions...

John

John,

You can use in the event two static variables (or one static point) to see
everytime if it changed,

I hope this helps,

Cor

Hi John,

which sizechanged event are you handling? Because I have written a bit of
code which does the same thing, and tried it in these 3 events and they all
only fire once, when I finish dragging the form border

Private Sub ptbImg_Resize(ByVal sender As Object, ByVal e As
System.EventArgs) Handles ptbImg.Resize
End Sub

Private Sub ptbImg_SizeChanged(ByVal sender As Object, ByVal e As
System.EventArgs) Handles _ ptbImg.SizeChanged
End Sub

Private Sub frmResize_SizeChanged(ByVal sender As Object, ByVal e As
System.EventArgs) Handles _ MyBase.SizeChanged

End Sub

greetz Peter

--
Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning.

"Cor Ligthert" <notmyfirstname@planet.nl> schreef in bericht
news:uq$esOOZFHA.3488@tk2msftngp13.phx.gbl...
[quoted text, click to view]

Thanks for the code. But it made no difference. Here is what I now
have:

Private Sub Pnl_Image_SizeChanged(...) Handles
Pnl_Image.SizeChanged
Static OldSize As Size
If Not OldSize.Equals(Pnl_Image.Size) Then
' call procedure to resize and display image
End If
End Sub

What am I missing?

John

John,

Sorry, I was reading it not well I thought that the picture stayed the same,
of course does this not help.

The only thing that I can come up that can help you here is probably a
timer.
We people are not able to see some things that fast.

I never tried it, however you can probably do it in the same way as
mysample, and than there is not much to change.

Private Sub Pnl_Image_SizeChanged(...) Handles
Pnl_Image.SizeChanged
Static OldTime As Integer
If (Environment.TicksCount - OldTime) > 50 Then
' call procedure to resize and display image
End If
OldTime = Environments.TicksCount
End Sub

And than set that 50 to a proper value.

Maybe this helps,

I am curious.

Cor

John, have you looked at my example?

in my opinion it does what you want.

Greetz Peter

--
Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning.

"johnb41" <orders@informatik.com> schreef in bericht
news:1117551471.570946.61990@g44g2000cwa.googlegroups.com...
[quoted text, click to view]

Cor,

That didn't make a difference. My procedure fires again and again
until I let go of the mouse.

It's actually not "as" bad now that i'm at work on a much faster
computer. But it's still annoying.

Any more suggestions, or should I just give up?

Thanks,
John

Cor,

Interesting idea, thanks!

But the only benefit it has is the image redraw happens a little less
frequently. And if I let go of the mouse at the wrong time, the image
doesn't redraw. I have to let go of the mouse immediately after it
redraws if I want the image displayed properly.

I played w/ the number value. A number too high refreshes too
infrequently, and often when I let go of the mouse, my subroutine
doesn't fire, and thus my image doesn't get resized/redrawn. A number
too low, and the effect is similar to the original code.

Well, I really appreciate all the help you've given me, Cor. But it
looks like this is pretty much impossible! :(

John

Peter,

Yes, I have. For me, the SizeChanged event fires again and again as
the Panel gets resized, not just when I let go of the mouse. Am I
missing something? Did you write any special code so it works as you
say?

John

Peter,

Yes, I have. For me, the SizeChanged event fires again and again as
the Panel gets resized, not just when I let go of the mouse. Am I
missing something? Did you write any special code so it works as you
say?

John

John,

I forgot it, however this is classic

[quoted text, click to view]

OldSize = Pnl_Image.Size

[quoted text, click to view]

I hope this helps,

:-)

Cor

Hi John, sorry for not responding faster, but after 5 o' clock (belgian
time), I haven't got access to the ng's for the moment (pc at home is broke)
The example I posted, runs very smooth at my computer, it only fires the
sizechanged event once, and that's when I release the form border after
resizing.
Which version of VS do you have? 2002, 2003? I have got 2003.

Greetz Peter

--
Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning.


"johnb41" <orders@informatik.com> schreef in bericht
news:1117553671.549306.262640@o13g2000cwo.googlegroups.com...
[quoted text, click to view]

I also find it very strange, if I put a msgbox in the sizechanged event of a
form, it first pops up before the form is even visible (that's just the form
initializing) and then when the form is loaded it only pops up AFTER I let
go of the mouse button, no extra code required.

For example the example I posted at my pc only fires the sizechanged event
after I let go of the mousebutton.

Greetz Peter

[quoted text, click to view]


--
Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning.

"johnb41" <orders@informatik.com> schreef in bericht
news:1117635224.936869.82610@g14g2000cwa.googlegroups.com...
[quoted text, click to view]

I have VS 2003 also. So let me get this straight, if you simply put in
a messagebox inside a Sizechanged event (for a Form), the messagebox
does not appear until AFTER you let go of the mouse button? No extra
code required?

Amazing. I can't even resize a form because the messagbox pops up too
soon.

If anyone else is reading this, does this happen to you also?

If this is true, i'm surprised that the others that posted in this
thread didn't mention it. Cor really went out of his way to help w/ a
couple potential solutions. Now i'm more confused than ever! (but that
isn't new)

John

Windows has an option called "Show Windows Contents While Dragging".

If this is turned on, you will receive a continuous stream of SizeChanged
events. If it is turned off, you only get a single SizeChanged event. Since
this is a user-defined setting, you need to account for both cases and make
your SizeChanged code as quick as possible. The same goes for Move events.

--
Jonathan Allen


[quoted text, click to view]

Jonathan,

Thanks for that info. I thought i was going crazy! So it looks like
i'm stuck w/ a sluggishly slow app when the user resizes the image
window. :(

John

John,

Can you try this one, I have taken the sample from Peter to test it this
time.

\\\
Public SwMoving As Boolean
Private Sub Panel1_SizeChanged(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles Panel1.SizeChanged
SwMoving = True
End Sub
Protected Overrides Sub WndProc(ByRef m As Message)
If m.Msg = &HA0 Then 'is up &HA1 is nonclientarea down
If SwMoving Then
If Not ptbImg.Image Is Nothing Then
loadimage(CStr(ptbImg.Tag))
End If
SwMoving = False
End If
End If
MyBase.WndProc(m)
End Sub
///

I hope that it this time helps,

Cor

John,

What you did not tell all the time in this thread is how you resize your
panel. I have the same as I think for others assumed that it was resized
accoording the resizing of the form. However was in doubt if it was because
of a slider.

Cor

John,

This works than like a splitter (I wrote slider) and when I had understood
this earlier, a lot easier. You set in the splitter mouse down event (your
control) a swMouseDown (a global value) to true.

In the Mouse Up event of that you set your resizing code in a kind of the
same way as in the previous example (of course a call to a sub) and set the
swMouseDown again to false.

As long as that mouse is down you do nothing and when it goes up again you
do your code.

Because that I don't know that control, did I write it in this way, I hope
that this explains it.

Cor

Cor,

Wow, thanks for the extra effort and help! I tried your code
(obviously had to tweak it a little to fit my app), and here's what
happened:

The panel (with picturebox) gets resized without any sluggishness in
the app. BUT the image does not get redrawn when i let go of the
mouse.

But whenever i move my mouse over the bar at the top of the form (i
can't remember the name; the bar that has the minimize, maximize and
close buttons) then sub routine fires that resizes and redisplays the
image.

Strange. If the image would resize to the new Panel size without having
to run my mouse over the top bar, then it would be perfect!!!

Here's my code:

Public SwMoving As Boolean
Private Sub Pnl_Image_SizeChanged(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Pnl_Image.SizeChanged
SwMoving = True
End Sub

Protected Overrides Sub WndProc(ByRef m As Message)
If m.Msg = &HA0 Then 'is up &HA1 is nonclientarea down
If SwMoving Then
If Not Pb_image.Image Is Nothing Then
'below is routine that resizes
'and redisplays the image.
'The image gets displayed in the
'form that THIS code is in.
Call displayimage(m_image, Me)
End If
SwMoving = False
End If
End If
MyBase.WndProc(m)
End Sub


Anyway to tweak it a little? Thanks so much!
John

I "thought" I mentioned it briefly somewhere. Anyway, here's how my
Panel gets resized:

The Panel is docked (Fill) on Form1. To the right of the panel is a
dockable window (thanks to dotnetbar (www.devcomponents.com)). When
the dockable window is resized (left to right) or hidden, the Panel
will resize accordingly. So that's how it's resized!

Is your code adaptable for my situation?

(by the way, if i resize my main form, it works really nice! :)

John

Hi Cor,

your example works nicely, I think John will be very pleased with it

Greetz Peter

--
Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning.


"Cor Ligthert" <notmyfirstname@planet.nl> schreef in bericht
news:#vUMu1tZFHA.3120@TK2MSFTNGP12.phx.gbl...
[quoted text, click to view]

In the MouseUp event, you say to call a sub. Do you mean the sub that
I created to do the resizing calculations, or the Sub WndProc that you
created? I tried the latter, and it needs a "message" argument. I
don't know what to put in there.

If i totally ignore the Sub WndProc, and just put in my procedure, then
i get unusual results. Sometimes my image gets redrawn, and sometimes
it does not. Most of the time it does not redraw. It's unpredictable.

So in summary, what of your original code do I keep?

John

John,

When it is in the case of a splitter you can use this code.
\\\
Private Sub Splitter2_SplitterMoved(ByVal sender As Object, _
ByVal e As System.Windows.Forms.SplitterEventArgs) Handles
Splitter2.SplitterMoved
If Not ptbImg.Image Is Nothing Then
loadimage(CStr(ptbImg.Tag))
End If
End Sub
///

When that wont go you can try this.

\\\However gives a little bit stranger effect
Public SwMoving As Boolean
Public swSplitterMouseMoving As Boolean
Private Sub Panel1_SizeChanged(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles Panel1.SizeChanged
SwMoving = True
End Sub

Protected Overrides Sub WndProc(ByRef m As Message)
If m.Msg = &HA0 Then
If SwMoving Then
If Not ptbImg.Image Is Nothing Then
loadimage(CStr(ptbImg.Tag))
End If
SwMoving = False
End If
SwMoving = False
End If
MyBase.WndProc(m)
End Sub
Private Sub Splitter2_MouseEnter(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Splitter2.MouseEnter
swSplitterMouseMoving = True
End Sub
Private Sub Splitter2_MouseLeave(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Splitter2.MouseLeave
If swSplitterMouseMoving Then
If SwMoving Then
If Not ptbImg.Image Is Nothing Then
loadimage(CStr(ptbImg.Tag))
End If
SwMoving = False
End If
SwMoving = False
End If
swSplitterMouseMoving = False
End Sub
///
I hope this helps,

Cor

Addendum:

\\\
Private m_Image As Image
Private m_Redraw As Boolean = True

Private Sub Form1_Load( _
ByVal sender As Object, _
ByVal e As EventArgs _
) Handles MyBase.Load
m_Image = Image.FromFile("C:\WINDOWS\Angler.bmp")
End Sub

Protected Overrides Sub WndProc( _
ByRef m As Message _
)
Const WM_ENTERSIZEMOVE As Int32 = &H231
Const WM_EXITSIZEMOVE As Int32 = &H232
Select Case m.Msg
Case WM_ENTERSIZEMOVE
m_Redraw = False
Case WM_EXITSIZEMOVE
m_Redraw = True
Me.Panel1.Invalidate()
End Select
MyBase.WndProc(m)
End Sub

Private Sub Panel1_Paint( _
ByVal sender As Object, _
ByVal e As PaintEventArgs _
) Handles Panel1.Paint
If m_Redraw Then
e.Graphics.DrawImage( _
m_Image, _
0, 0, _
Me.Panel1.ClientSize.Width, Me.Panel1.ClientSize.Height _
)
End If
End Sub
///

However, this solution would prevent the panel from redrawing if the window
is dragged by the mouse.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

Herfried,

The main problem is a
dockable window (thanks to dotnetbar (www.devcomponents.com)).

The rest of the solutions where already given (I think mine is nicer), do
you know something about this control and to stop actions using this while
resizing.

Cor

"Cor Ligthert" <notmyfirstname@planet.nl> schrieb:
[quoted text, click to view]

'&HA0' is 'WM_NCMOUSEMOVE'! In addition to that, note that the user can
change the size of a window using the keyboard (Alt+Space -> "Resize" ->
arrow keys), which won't fire non-client mouse events. All together I don't
see the benefits of your solution.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

Herfried,

[quoted text, click to view]

A good addition. However for that can be tested in this procedure probably
just keyup &H291 with orelse (I did not test it).

I could not find all those shortcuts from C++ on Google, however I have now
copied a page from Bob Powell where it is was in, therefore I have them now
saved in my HKW system.

I thought yesterday it would be a nice extension if somebody like Herfried
makes a nice dll so that we can get those in the same way as all other
enumerations.

When you need that information from Bob Powell to make this than I can sent
them you by mail. (Before you say it, yes I can make it myself as well
however it looks so nice as a link to your page)

The Herfried.K.Wagner namespace extension to the framework.

:-)

Cor

Cor,

"Cor Ligthert" <notmyfirstname@planet.nl> schrieb:
[quoted text, click to view]

Untested:

A Win32 Library for .NET
<URL:http://www.codeproject.com/csharp/win32.asp>

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

Herfried,

I will have a look at it, (as you know, do I hate sites which wants my
emailadres, although I know from you that this one is harmless)

Thanks,

Cor

Cor,

"Cor Ligthert" <notmyfirstname@planet.nl> schrieb:
[quoted text, click to view]

Yeah, I hate them too because I have to lookup my password every time I log
in.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

Sorry I couldn't try your suggestions out until now. ... and thanks
for the continued help with this! Unfortunately the dotnetbar
"dockable window" does not have a splitter that has events. No
splitter at all that I can see. It's probably using one in the
background, but I have no idea how to access it.

I think i'm just going to lay this issue to rest. I will not bother
having an instantly re-drawable picturebox/panel. Thanks again for all
your help!!!

John

Herfried,

I tried your code, but in my app it produced some side effect errors
that I could not figure out. As I wrote to Cor above, I decided to
just give up on this effect. But at least this thread was not for
nothing... it does have some valuable code for having the SizeChanged
event fire once if the "form" itself is resized.

Thanks!
John