Hi all,

I got a problem: I have a Panel control which has many mixed child controls
(buttons, checkboxes, comoboxes). All controls are visible (the parent
container Panel is also visible). My problem is that when I set the Visible
property of the Panel to false and try to read the Visible property of any
of its child control, the result is always false??? How can I get the
original value of the Visible property of any child control??

I'd appreciate your prompt reply,

Thanks a lot ..

Veszko

/****************************/

Panel pnl = new Panel();
..
..
..
pnl.Visible = true;

Button btn = new Button();
..
..
..
btn.Visible = true;

pnl.Controls.Add(btn);

..
..
..
MessageBox.Show(pnl.Visible.ToString()); // The result is "True"
MessageBox.Show(btn.Visible.ToString()); // The result is "True"

pnl.Visible = false;

MessageBox.Show(pnl.Visible.ToString()); // The result is "False"
MessageBox.Show(btn.Visible.ToString()); // The result is "False" ...
which is not OK!!!

// I need to know the original value of "btn.Visible"

/****************************/

since the panel is the parent, anything that happens with it's
visiblity will be pushed down to the children. You really don't want
to mess with that behavior at all. However, there is something you
can do to keep the last state of the visibility of the control.

Override the Visible property in each of your child controls with

private bool _LastVisibility;

public new bool Visible
{
get
{
return base.Visible;
}
set
{
_LastVisibility = value;
base.Visible = value;
}
}

public bool LastVisibility
{
get
{
return _LastVisibility;
}
}


that will allow you to save the last visible state that any given
control was set to. You can get that last state by checking your new
'LastVisibility' property.


Allen Anderson
http://www.glacialcomponents.com
mailto: allen@put my website url here.com


On Fri, 18 Jun 2004 15:54:18 +0200, "Wesam" <public_2000>
wrote:
[..]

Thanks Allen for your reply, unfortunately, this is not a practical solution
because this is a general problem in all our software programs and somehow I
have to fix ... Overriding each control's Visible property takes a long time
and makes very difficult to modify the program in the future, could you
help?

May thanks,

Veszko

"Allen Anderson" <allen> wrote in message
news:sq7j
[..]

Use reflection and call the internal method GetState
passing the parameter STATE_VISIBLE (0x2)

/claes

"Wesam" <public_2000> wrote in message
news:3988
[..]

Dear Claes!

Thank you for your reply, but could you provide me with some simple source
code? unfortunately I was unable to both "GetState" & "STATE_VISIBLE" in
MSDN ...
Your solution seems to be interesting!

I'd appreciate your help,

Veszko

"Claes Bergefall" <claes.bergefall> wrote in message
news:2928
[..]

Public Function CallMethod(ByVal name As String, ByVal o As Object, ByVal
ParamArray params() As Object) As Object
Dim objectType As Type = o.GetType
Dim flags As BindingFlags = BindingFlags.Instance Or _
BindingFlags.Static Or _
BindingFlags.NonPublic Or _
BindingFlags.Public
Dim methodInfo As methodInfo
Dim param As Object
Dim types(params.Length - 1) As Type
Dim index As Integer
For index = 0 To params.Length - 1
types(index) = params(index).GetType
Next
While Not objectType Is Nothing
methodInfo = objectType.GetMethod(name, flags, Nothing, types,
Nothing)
If methodInfo Is Nothing Then
objectType = objectType.BaseType
Else
Exit While
End If
End While
If methodInfo Is Nothing Then
Throw New MissingMemberException(o.GetType.FullName, name)
Else
Return methodInfo.Invoke(o, params)
End If
End Function


Call like this:
Dim visible As Boolean = CBool(CallMethod("GetState", myLabel, 2))

/claes

"Wesam" <public_2000> wrote in message
news:3336
[..]

Dear Claes,

Thanks for your help, but unfortunately I wan unable to use the code you put
here for two reasons: I can understand C# code, and because for some reason
the code is not complete or so ... my VB.NET reported many errors (syntax)
and I could not use it?? Could you help me please!

Thank you for all your help,

Wesam

"Claes Bergefall" <claes.bergefall> wrote in message
news:2928
[..]

I think you are going to have a hard time doing that without
intercepting the call that hides or dispalys the child controls. See,
the problem is that the controls really ARE being set to hidden. When
the parent is not displayed, it calls the hide on the children as
well. So where as you think you are trying to get to some value under
the hood where things have their old value, I don't believe there is
such a thing. When a parent is no longer displayed, it iterates the
children and hides them too. At least that is my understanding of how
the framework works.

Allen Anderson
http://www.glacialcomponents.com
mailto: allen@put my website url here.com

On Mon, 21 Jun 2004 09:28:23 +0200, "Wesam" <public_2000>
wrote:
[..]

Dear Allen,

Thanks for your reply, however, I disagree with you! 100% the parent's
"Visible" or "Hide()" does not call similar methods on the children because
it somehow maintains the original state of each control! For instance, in my
previous example the child controls are hidden when the parent is hidden
(although some of them could originally be visible or hidden) but when you
set the parent's "Visible" to true, fortunately (and this what makes me
believe is it possible) all child control are set back to their original
"Visible" value which -in turn- makes clear that the each control -somehow-
ALWAYS RETURNS FALSE if the parent's "Visible" is false!! And thus when the
parent's "Visible" is true, then the real value of the child control is
RETURNED

I think something like that happens, and I feel that there's a way to solve
this ... but I don't know how? do you have any ideas?

Thanks,

Veszko

"Allen Anderson" <allen> wrote in message
news:c5u0
> I think you are going to have a hard time doing that without
> intercepting the call that hides or dispalys the child controls. See,
> the problem is that the controls really ARE being set to hidden. When
> the parent is not displayed, it calls the hide on the children as
> well. So where as you think you are trying to get to some value under
> the hood where things have their old value, I don't believe there is
> such a thing. When a parent is no longer displayed, it iterates the
> children and hides them too. At least that is my understanding of how
> the framework works.
>
> Allen Anderson
> [..]
> mailto: allen@put my website url here.com
>
> On Mon, 21 Jun 2004 09:28:23 +0200, "Wesam" <public_2000>
> wrote:
>
solution
> >because this is a general problem in all our software programs and
somehow I
[..]

??? The code I posted is in VB.NET!
You're probably missing an Imports System.Reflection
statement

/claes

"Wesam" <public_2000> wrote in message
news:2176
[..]

I am not missing the "System.Reflection" .. I did include it into the
program, however, the complier did not report Imports missing or something
like this, it said there syntax errors and invalid casting and stuff like
that. I did a Copy/Paste the code you provided AS-IS into a new VB.NET
project (because I did not learn VB that much I did not change anything, I
just added the missing Reflection namespace) and that's why I could not
figure out the reason. Could you help me?

Many thanks,

Veszko

"Claes Bergefall" <claes.bergefall> wrote in message
news:3512
[..]

Copying/pasting the code AS-IS works just fine
You do know that the news-client adds line-breaks
on long lines, right?

What errors are you getting?

/claes

"Wesam" <public_2000> wrote in message
news:4064
[..]

Dear Claes!

I so sorry for the inconvenience, my Visual Basic is corrupted and that's
why nothing worked :-(( Your example works very very well, I tried it on my
colleague's machine and it good. However, I would ask you some final
question (if you allow me): Can you convert this code somehow to C#??? Now I
have a working VS.NET (VB & C#) but I am mainly a C# programmer and I have
to use your code in my program and I am not sure I can do that, could you
help me? If not possible could just give general guides of how all this is
working fine?

I really appreciate your valuable help,

Thanks,

Veszko

"Claes Bergefall" <claes.bergefall> wrote in message
news:1048
[..]

Dear Claes,

I managed to convert the code to C#, thanks to you, however, I have a
question: how did you know that there's a "GetState()" method and there's a
parameters for it which "2"?? I could not find information about this issue
nowhere? would you provide me with info please!

Many thanks in advance,

Veszko

"Wesam" <public_2000> wrote in message
news:3972
[..]

I looked at the source code for the framework :-)
Download .NET Reflector and do the same:
http://www.aisto.com/roeder/dotnet/
(it's at the top)

/claes


"Wesam" <public_2000> wrote in message
news:a808
[..]