problems using the tablelayoutpanel in VS2005

[lars.mollerup]

Sorry if I am posting in wrong group...

I am having a problem adding controls dynamically to this control
( using tablelayoutpanel.add(col,row)).

I am doing this to a cell where there is an existing control. I
thought this would just move the existing control to the next
available cell and so on. (Growstyle is rows). The controls are added
in a strange way and the order of the added controls seems to be
dependent on what kind of control I am adding!?

I will be happy for any comment on this matter.

Lars
)

 

[Peter Duniho]

Sorry if I am posting in wrong group...

I am having a problem adding controls dynamically to this control
( using tablelayoutpanel.add(col,row)).

There's no TableLayoutPanel.Add() method.

I am doing this to a cell where there is an existing control. I
thought this would just move the existing control to the next
available cell and so on. (Growstyle is rows). The controls are added
in a strange way and the order of the added controls seems to be
dependent on what kind of control I am adding!?

Perhaps you could be more specific. What does the code you're using to
add controls look like exactly? What behavior did you expect? What
behavior did you get instead?

Pete

 

[Larsemann]

There's no TableLayoutPanel.Add() method.


Perhaps you could be more specific. What does the code you're using to
add controls look like exactly? What behavior did you expect? What
behavior did you get instead?

Pete

I'll give a brief description of the problem; I am inserting a row of
controls in the tablelayoutpanel. There is no such thing as a .addrow
method to the control so I use.
tablelayoutpanel.controls.add(control,colnr,rownr). I add a control
into a cell allready inhabited by a control. I think the existing
control is suppose to float to the right. Growstyle is set to rows. I
have 7 cols thus after doing this 7 times I have inserted a row. But
the result is trange. The order of the inserted controls seem allmost
arbitrary and dependent of what kind og control I insert (textbox,
checkbox etc.). I am sure there must be a bug in the tablelayoutpanel
but will be happy for any ideas.

Lars
)

 

[Peter Duniho]

[...] I add a control
into a cell allready inhabited by a control. I think the existing
control is suppose to float to the right. Growstyle is set to rows. I
have 7 cols thus after doing this 7 times I have inserted a row. But
the result is trange. The order of the inserted controls seem allmost
arbitrary and dependent of what kind og control I insert (textbox,
checkbox etc.). I am sure there must be a bug in the tablelayoutpanel
but will be happy for any ideas.

Well, again you have failed to post the code you're using. It's pretty
much impossible to tell you what is going wrong without knowing what it
is you're actually doing.

For you to get any useful help, you need to put together and post a
concise-but-complete example of code that reliably demonstrate the
problem. "Concise" mean you only include the bare minimum required to
demonstrate the problem. "Complete" means one doesn't have to add
anything at all to get the code to compile and run (yes, for a
forms-based application this means including the designer-created code
too, unless you write something from scratch without the designer).

As for there being a bug in TableLayoutPanel, that's extremely
unlikely. I wouldn't go so far as to say there are no bugs in .NET --
any sufficiently complex piece of software will have bugs -- but they
are extremely rare relative to the size of the framework, and I've
never seen a bug in a part of the framework that's as commonly used as
the TableLayoutPanel.

It's not unusual for someone to post here that they think they've found
a bug in .NET. I can't recall a single instance of such a claim
turning out to be correct.

It's much more likely that you've made some assumption about the
behavior of adding controls to the panel that's incorrect, and thus
your expectations don't match the actual behavior. But until you post
something more explicit, there's no way to help explain the disparity.

Pete

 

[Larsemann]

[...] I add a control
into a cell allready inhabited by a control. I think the existing
control is suppose to float to the right. Growstyle is set to rows. I
have 7 cols thus after doing this 7 times I have inserted a row. But
the result is trange. The order of the inserted controls seem allmost
arbitrary and dependent of what kind og control I insert (textbox,
checkbox etc.). I am sure there must be a bug in the tablelayoutpanel
but will be happy for any ideas.

Well, again you have failed to post the code you're using. It's pretty
much impossible to tell you what is going wrong without knowing what it
is you're actually doing.

For you to get any useful help, you need to put together and post a
concise-but-complete example of code that reliably demonstrate the
problem. "Concise" mean you only include the bare minimum required to
demonstrate the problem. "Complete" means one doesn't have to add
anything at all to get the code to compile and run (yes, for a
forms-based application this means including the designer-created code
too, unless you write something from scratch without the designer).

As for there being a bug in TableLayoutPanel, that's extremely
unlikely. I wouldn't go so far as to say there are no bugs in .NET --
any sufficiently complex piece of software will have bugs -- but they
are extremely rare relative to the size of the framework, and I've
never seen a bug in a part of the framework that's as commonly used as
the TableLayoutPanel.

It's not unusual for someone to post here that they think they've found
a bug in .NET. I can't recall a single instance of such a claim
turning out to be correct.

It's much more likely that you've made some assumption about the
behavior of adding controls to the panel that's incorrect, and thus
your expectations don't match the actual behavior. But until you post
something more explicit, there's no way to help explain the disparity.

Pete

Hello and thanks for reply.

I know that claiming a bug seems a bit far out but quite few of my
highly experienced collegues have looked into the solution and comes
up with the same response. There must be a bug! You state that it is
a commonly used control. I am not sure that is correct, at least not
adding/manipulating it dynamically. I have searched the net
extensively and am not able to find much about the topic. You want me
to give you more code. I'll be happy to mail you the entire soulktion
if you want to. For now I will give you the method adding the row, plz
let me know if there are some obvious mistakes or misunderstandings on
my behalf.


Lars
)

public void settinn_linje(Control[] Kontroller)
{
this.tableLayoutPanel1.Visible = false;

int intLinjetrykket =
this.tableLayoutPanel1.GetRow(this.ActiveControl);
for (int teller = 6; teller > -1 ; teller--)
{
if (teller == 0 | teller == 1 | teller == 2)
{
TextBox midBox = new TextBox();
midBox.Text = Kontroller[teller].Text;
this.tableLayoutPanel1.Controls.Add(midBox,
0,intLinjetrykket);

}
if (teller == 3)
{
TextBox midBox = new TextBox();
midBox.Text = Kontroller[teller].Text;
this.tableLayoutPanel1.Controls.Add(midBox,
0,intLinjetrykket);

}
if (teller == 4 | teller == 5 | teller == 6)
{
CheckBox midBox = new CheckBox();
midBox = (CheckBox)Kontroller[teller];
this.tableLayoutPanel1.Controls.Add(midBox, 0,
intLinjetrykket);

}

}

bool_Ischanged = true;
this.tableLayoutPanel1.Visible = true;
}

 

[Peter Duniho]

I know that claiming a bug seems a bit far out but quite few of my
highly experienced collegues have looked into the solution and comes
up with the same response. There must be a bug!

So you say. I remain unconvinced.

You state that it is
a commonly used control. I am not sure that is correct, at least not
adding/manipulating it dynamically. I have searched the net
extensively and am not able to find much about the topic. You want me
to give you more code. I'll be happy to mail you the entire soulktion
if you want to.

No, I do not want you to. If you want the best answer, you need to
post an appropriate sample of code here in this newsgroup.

For now I will give you the method adding the row, plz
let me know if there are some obvious mistakes or misunderstandings on
my behalf.

Even the short example you posted fails both the "concise" and
"complete" criteria. It's not concise because there's apparently more
in the example than is needed to reproduce the problem, and it's not
complete because I can't just compile the whole thing without adding
other stuff to get it to work.

The fact that the code is not complete also means that we have no
information on the state of the control prior to calling the method you
posted. How many controls have already been added? Where where they
added? And why do you create a new CheckBox() control, only to replace
it with an existing CheckBox() from your Kontroller array? Do you
understand that a control can only be in one cell at a time, so if you
are calling Add() with a reference to a control that you've already
placed in the TableLayoutPanel somewhere, it will be removed from its
existing location and added where you tell it to?

I will say one thing about the code you did post: you should be using
the "||" operator in your if() statements, and not the "|" operator.
Whatever "highly experience colleagues" you showed your code to should
have told you the same thing. Since == has higher precedence than |, I
would guess this isn't causing a problem here. But it certainly isn't
a good way to write the code.

And the million dollar question: have you stepped through the code in a
debugger to ensure that it is in fact adding the controls you expect it
to, when you expect it to? There really is no substitute for watching
the code executed, when trying to find out why when it executes it
doesn't do what you expect it to.

Pete

 

[Larsemann]

So you say. I remain unconvinced.


No, I do not want you to. If you want the best answer, you need to
post an appropriate sample of code here in this newsgroup.


Even the short example you posted fails both the "concise" and
"complete" criteria. It's not concise because there's apparently more
in the example than is needed to reproduce the problem, and it's not
complete because I can't just compile the whole thing without adding
other stuff to get it to work.

The fact that the code is not complete also means that we have no
information on the state of the control prior to calling the method you
posted. How many controls have already been added? Where where they
added? And why do you create a new CheckBox() control, only to replace
it with an existing CheckBox() from your Kontroller array? Do you
understand that a control can only be in one cell at a time, so if you
are calling Add() with a reference to a control that you've already
placed in the TableLayoutPanel somewhere, it will be removed from its
existing location and added where you tell it to?

I will say one thing about the code you did post: you should be using
the "||" operator in your if() statements, and not the "|" operator.
Whatever "highly experience colleagues" you showed your code to should
have told you the same thing. Since == has higher precedence than |, I
would guess this isn't causing a problem here. But it certainly isn't
a good way to write the code.

And the million dollar question: have you stepped through the code in a
debugger to ensure that it is in fact adding the controls you expect it
to, when you expect it to? There really is no substitute for watching
the code executed, when trying to find out why when it executes it
doesn't do what you expect it to.

Pete

I will leave it here. Your ironic tone is starting to bug me.