how to check if a form is already open

[TM]

Is there any way to check if a form is already pen and if so set the focus
to it instead of opening another instance of that form ?

Thanks
--
Tony

[Cor]

Hi Tonny,

Is there any way to check if a form is already pen and if so set the focus
to it instead of opening another instance of that form ?

Hi Tonny, sorry that I have to write this, but this is the answer.

"Use good program logic"

Cor

[Herfried K. Wagner [MVP]]

* "TM" <no********@nothing.com> scripsit:

Is there any way to check if a form is already pen and if so set the focus
to it instead of opening another instance of that form ?

Have a Google Search for "Singleton Design Pattern".

--
Herfried K. Wagner [MVP]
<http://www.mvps.org/dotnet/>

[Chris Morse]

On Tue, 24 Feb 2004 23:59:17 -0500, "TM" <no********@nothing.com>
wrote:

Is there any way to check if a form is already pen and if so set the focus
to it instead of opening another instance of that form ?

Thanks

It's not very easy. You could use Win API functions to enumerate all
windows and look for the window in question. (eg, EnumThreadWindows)

I had hoped that the static .NET function
System.Windows.Forms.Form.ActiveForm() would help me determine if ANY
forms were open besides the "main" form.

Unfortunately, I found it had a few quirks that limited its usefulness
for me:

(1) ActiveForm returns "Nothing" if the application does not
have focus.
(2) .. Returns "Nothing" if a non-application form is being
displayed (eg, a MsgBox() is open)

I think that you'll have to either resort to a windows enumeration or
building the functionality by adding code to implement the "singleton"
design pattern.

// CHRIS

[TM]

Sorry but that is not an answer. I am new to .Net and have no idea how to
do this in vb.net.

I have a button to add a new record into the database which opens a form
with the fields and such.

I want to prevent someone from opening that form more than once
--
Tony

"Cor" <no*@non.com> wrote in message
news:up****************@TK2MSFTNGP10.phx.gbl...

Hi Tonny,

Is there any way to check if a form is already pen and if so set the focus to it instead of opening another instance of that form ?

Hi Tonny, sorry that I have to write this, but this is the answer.

"Use good program logic"

Cor

[Cor]

Hi Tony,

Use good program logic was the answer.

What is not good on it. There are so many logical methods for that.
One sample.

If you want to prevent that the form is opened twice you set that button to
invisible and set it to visible if the form is closed.

Very easy and simple programming logic.

Cor

[Chris Morse]

On Wed, 25 Feb 2004 14:27:48 -0500, "TM" <no********@nothing.com>
wrote:

Sorry but that is not an answer. I am new to .Net and have no idea how to
do this in vb.net.

I have a button to add a new record into the database which opens a form
with the fields and such.

I want to prevent someone from opening that form more than once
--
Tony

In that case, just define the form normally and call it like this:

Dim myForm As New FormName
myForm.ShowDialog()

Then the user interface will be essentially disabled until the user is
done with the form... a basic "modal" form..

// CHRIS

[dakine181]

Cor wrote:

*Hi Tonny,

Is there any way to check if a form is already pen and if so set

the focus

to it instead of opening another instance of that form ?

Hi Tonny, sorry that I have to write this, but this is the answer.

"Use good program logic"

Cor *

Only registered to reply to this post. I was looking for similiar
answers/solutions.Felt compelled to reply to it even though it's such
an old post.

This kind of post doesn't help one bit. It's like a teacher you had
back in school you asked for help on a spelling of a word. Thier reply
is look it up in the dictionary.

i've got a helpful reply

'Go seek the holy grail' thats were you will find your answer

Suffice to say this post was no f****** help at all and just someones
lazy 'I'm better than you' poor attitude.

Dakine

--
dakine181
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