Why does Sub work but not function

[greg_quinn]

I have a form in my app named frmMain

In the form I have a Sub

Public Sub mySub()
End Sub

and a function

Public Funtion GetValue() as Long
GetValue = 100
End Function


Now when I call mySub from another form, I do something like

Dim frM as frmMain

frmMain.mySub()

And that works fine..

But why can't I get the return value of the GetValue() function?

i.e

Dim frM as frmMain
Dim myValue as Long

myValue = frmMain.GetValue()

It returns an error, object reference not set to instance of an object...

Thanks

[HumePeabody]

Just a guess without actually trying it, but try this instead...

Dim frm as New frmMain
Dim myValue as Long

myValue = frm.GetValue()

Now you are calling the method of the frm object (of frmMain type). Before you did not actually have an object created to call the method. I'm not sure why the Sub should allow this behavior in the first place...

[wossname]

Originally posted by greg_quinn

And that works fine..

No it doesn't.

[SeanGrebey]

I would also suggest you get in the habit of using return statements. Since VB.NET includes them now, they tend to make the code more read friendly.

[taxes]

Originally posted by greg_quinn
I have a form in my app named frmMain

In the form I have a Sub

Public Sub mySub()
End Sub

and a function

Public Funtion GetValue() as Long
GetValue = 100
End Function


Now when I call mySub from another form, I do something like

Dim frM as frmMain

frmMain.mySub()

And that works fine..

But why can't I get the return value of the GetValue() function?

i.e

Dim frM as frmMain
Dim myValue as Long

myValue = frmMain.GetValue()

It returns an error, object reference not set to instance of an object...

Thanks

Sorry but you are all screwed up here (I think )

It looks as though your frmMain is NOT the startup object of your project. In that case;

Dim frM as frmMain should be

Dim frM as New frmMain

and frmMain.mySub should be

frM.mySub

mySub will have to be Public and so will myValue.

Try that and see what happens.

By the way, I agree with wossname, none of your code can possibly work

[greg_quinn]

Sorry, I must admit I didn't go through my post after I wrote it.

Adding the New to the Form declaration helps everything.

(Although I swear I tried that and it didn't work before



But then again its been a long day!!)

Thanks for the help