Updating a variable in a Parent Form from a dialog box.

[Jesse]

Hi All,

Just wanted to know how to update a public variable in a parent form from a
dialog box. It appears that i get a null reference error when assigning the
variable as follows:

((FormMain)this.ParentForm).loggedIn = true;

Can anybody shed some light?

Thanks,
Jesse

[Zürcher See]

I'm not sure, but i think that if is not a modal form, it has (as default)
no parent.

But you can always set it when you istantiate it

Form myChildForm=new Form();
myChildForm.Parent=this;

"Jesse" <je*****@hotmail.com> schrieb im Newsbeitrag
news:eW**************@TK2MSFTNGP12.phx.gbl...

Hi All,

Just wanted to know how to update a public variable in a parent form from a dialog box. It appears that i get a null reference error when assigning the variable as follows:

((FormMain)this.ParentForm).loggedIn = true;

Can anybody shed some light?

Thanks,
Jesse

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

I would do another thing, I will pass a reference to the parent to the
constructor of the dialog:

Form childform = new ChildForm( this );
childform.ShowDialog();

Hope this help,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Zürcher See" <aq****@cannabismail.com> wrote in message
news:On**************@TK2MSFTNGP10.phx.gbl...

I'm not sure, but i think that if is not a modal form, it has (as default)
no parent.

But you can always set it when you istantiate it

Form myChildForm=new Form();
myChildForm.Parent=this;

"Jesse" <je*****@hotmail.com> schrieb im Newsbeitrag
news:eW**************@TK2MSFTNGP12.phx.gbl...

Hi All,

Just wanted to know how to update a public variable in a parent form

from a

dialog box. It appears that i get a null reference error when assigning

the

variable as follows:

((FormMain)this.ParentForm).loggedIn = true;

Can anybody shed some light?

Thanks,
Jesse

[Philip Rieck]

ParentForm is really a property to get the form that your control is sited
on, (which is very handy for MDI forms). Try using "Parent" instead:

In your calling form (FormMain):

ChildForm cf = new ChildForm();
cf.Parent = this;
cf.Show();
Then in your child form:

((FormMain)this.Parent).loggedIn = true;

"Jesse" <je*****@hotmail.com> wrote in message
news:eW**************@TK2MSFTNGP12.phx.gbl...

Hi All,

Just wanted to know how to update a public variable in a parent form from a dialog box. It appears that i get a null reference error when assigning the variable as follows:

((FormMain)this.ParentForm).loggedIn = true;

Can anybody shed some light?

Thanks,
Jesse

[Jesse]

Thanks for the help. All very good suggestions.
"Jesse" <je*****@hotmail.com> wrote in message
news:eW**************@TK2MSFTNGP12.phx.gbl...

Hi All,

Just wanted to know how to update a public variable in a parent form from a dialog box. It appears that i get a null reference error when assigning the variable as follows:

((FormMain)this.ParentForm).loggedIn = true;

Can anybody shed some light?

Thanks,
Jesse