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C# main class access

How do you access properties of the main program's class from another form? There does not apear to be an instance variable that can be used.

Nov 16 '05 #1
3 17891
Hi Ray,

"Ray Stevens" <Ra********@discussions.microsoft.com> wrote in message
news:DF**********************************@microsof t.com...
How do you access properties of the main program's class from another
form? There does not apear to be an instance variable that can be used.


A) Pass a reference to your main form when creating others.
B) Implement an public application singleton, containing the base logic -
which
may include a Collection of all the created forms - then you can access
the
singleton's collection of forms whenever you feel like doing form2form
communication ;-)

--
Lars Wilhelmsen
http://www.sral.org/
Software Engineer
Teleplan A/S, Norway
Nov 16 '05 #2
That means the functions that are opening the new forms are static methods
of the main form instead of instance methods. Is this on purpose, and, if
so, is there a reason they need to be this way?

Regardless, here's a pretty simple way of doing this. In you main form,
create a public static variable and use it for the call to
Application.Run(), e.g.

class MainForm : System.Windows.Forms.Form
{
public static MainForm TheMainForm = null;

public static void Main()
{
TheMainForm = new MainForm();
Application.Run(TheMainForm);
}
}

Now in any other form, if you need to reference the main form, do this:

class SomeOtherForm : System.Windows.Forms.Form
{
public SomeMethod()
{
string s = MainForm.TheMainForm.GetValueOfSomeTextBox();
}
}
Ken

"Ray Stevens" <Ra********@discussions.microsoft.com> wrote in message
news:58**********************************@microsof t.com...
Passing a reference to the main form does not work. The compiler give an error "can't reference 'this'". I still can not find the instance variable
for the main form.
"Lars Wilhelmsen" wrote:
Hi Ray,

"Ray Stevens" <Ra********@discussions.microsoft.com> wrote in message
news:DF**********************************@microsof t.com...
How do you access properties of the main program's class from another
form? There does not apear to be an instance variable that can be used.


A) Pass a reference to your main form when creating others.
B) Implement an public application singleton, containing the base logic - which
may include a Collection of all the created forms - then you can access the
singleton's collection of forms whenever you feel like doing form2form communication ;-)

--
Lars Wilhelmsen
http://www.sral.org/
Software Engineer
Teleplan A/S, Norway

Nov 16 '05 #3
Hi Ken,

To answer your question: I don't know other than that is what VS.NET 2003 produced.

What you showed me worked. Thank you.

Ray Stevens

"Ken Kolda" wrote:
That means the functions that are opening the new forms are static methods
of the main form instead of instance methods. Is this on purpose, and, if
so, is there a reason they need to be this way?

Regardless, here's a pretty simple way of doing this. In you main form,
create a public static variable and use it for the call to
Application.Run(), e.g.

class MainForm : System.Windows.Forms.Form
{
public static MainForm TheMainForm = null;

public static void Main()
{
TheMainForm = new MainForm();
Application.Run(TheMainForm);
}
}

Now in any other form, if you need to reference the main form, do this:

class SomeOtherForm : System.Windows.Forms.Form
{
public SomeMethod()
{
string s = MainForm.TheMainForm.GetValueOfSomeTextBox();
}
}
Ken

"Ray Stevens" <Ra********@discussions.microsoft.com> wrote in message
news:58**********************************@microsof t.com...
Passing a reference to the main form does not work. The compiler give an

error "can't reference 'this'". I still can not find the instance variable
for the main form.

"Lars Wilhelmsen" wrote:
Hi Ray,

"Ray Stevens" <Ra********@discussions.microsoft.com> wrote in message
news:DF**********************************@microsof t.com...
> How do you access properties of the main program's class from another
> form? There does not apear to be an instance variable that can be used. >

A) Pass a reference to your main form when creating others.
B) Implement an public application singleton, containing the base logic - which
may include a Collection of all the created forms - then you can access the
singleton's collection of forms whenever you feel like doing form2form communication ;-)

--
Lars Wilhelmsen
http://www.sral.org/
Software Engineer
Teleplan A/S, Norway


Nov 16 '05 #4

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