Problem calling a Sub in another form

[vitorjol]

Hello.

I have 2 forms (Form1 and Form2). When i call the Sub placed in form1 from
form2, i get the error "object reference not set to an instance of an object"
!
What can i do to solve the problem?

Thanks

[Daniel Bloch]

Daniel Bloch schrieb:

What I see is that you do not show the form BringToFront does not make
a control a top-level control, and it does not raise the Paint event.

So with the knowledge of the last post, try following

- Check, if you can run the sub from form2 alone. Implement a button to
show what you want and make a test like this.
- If this does not work, first correct the sub until you are able to
let it run.
- After that, first show the new form and then let sub run from
form1...

Daniel

Sorry, I did a mistake and mixed form1 and form2 :)

[vitorjol]

The SUB in form2:

Public Sub soumavez(ByVal varin As Integer)
Try
MessageBox.Show (varin)
Dim pubmapsel As MGMapControl.MG Selection
Dim pubvar2 As MGMapControl.MG MapLayer
Dim pubmapobjectos As MGMapControl.MG Collection
Dim pubmapobj As MGMapControl.MG MapObject
pubmapsel = mgmap.getSelect ion()
pubvar2 = mgmap.getMapLay er("SIG")
pubmapobjectos = mgmap.createObj ect("MGCollecti on")
pubmapobj = mgmap.getMapLay er("SIG").getMa pObject(varin)
pubmapobjectos. add(pubmapobj)
mgmap.getSelect ion().addObject sEx(pubmapobjec tos, False)
mgmap.zoomSelec ted()
mgmap.zoomScale (mgmap.getLat() , mgmap.getLon(), 1500)
mgmap.refresh()
Catch ex As Exception
MessageBox.Show (ex.Message, "Erro", MessageBoxButto ns.OK,
MessageBoxIcon. Error)
End Try

End Sub
this sub is called form Form2 with the following code:

exitvar = DataGridView1.R ows(e.RowIndex) .Cells(0).Value
Dim ff As New Form1
ff.BringToFront ()
ff.soumavez(exi tvar)

PROBLEM:

if i dont put the codeline "MessageBox.Sho w(varin)", occurs the error at
line "pubmapobj = mgmap.getMapLay er("SIG").getMa pObject(varin)" .
If i put the message "MessageBox.Sho w(varin)", occurs the error at line
"mgmap.getSelec tion().addObjec tsEx(pubmapobje ctos, False)".

the test that u say to do (call the sub from a buttonclick within Form1)
occurs with NO Error!!!!

Thanks

"Daniel Bloch" wrote:

>
Daniel Bloch schrieb:

What I see is that you do not show the form BringToFront does not make
a control a top-level control, and it does not raise the Paint event.

So with the knowledge of the last post, try following

- Check, if you can run the sub from form2 alone. Implement a button to
show what you want and make a test like this.
- If this does not work, first correct the sub until you are able to
let it run.
- After that, first show the new form and then let sub run from
form1...

Daniel

Sorry, I did a mistake and mixed form1 and form2 :)

[vitorjol]

Resume my problem:
if i call the Sub located in Form1 from Form1 i get no error. If i call the
Sub from Form2 i get error. Why?

Thanks

"vitorjol" wrote:

The SUB in form2:

Public Sub soumavez(ByVal varin As Integer)
Try
MessageBox.Show (varin)
Dim pubmapsel As MGMapControl.MG Selection
Dim pubvar2 As MGMapControl.MG MapLayer
Dim pubmapobjectos As MGMapControl.MG Collection
Dim pubmapobj As MGMapControl.MG MapObject
pubmapsel = mgmap.getSelect ion()
pubvar2 = mgmap.getMapLay er("SIG")
pubmapobjectos = mgmap.createObj ect("MGCollecti on")
pubmapobj = mgmap.getMapLay er("SIG").getMa pObject(varin)
pubmapobjectos. add(pubmapobj)
mgmap.getSelect ion().addObject sEx(pubmapobjec tos, False)
mgmap.zoomSelec ted()
mgmap.zoomScale (mgmap.getLat() , mgmap.getLon(), 1500)
mgmap.refresh()
Catch ex As Exception
MessageBox.Show (ex.Message, "Erro", MessageBoxButto ns.OK,
MessageBoxIcon. Error)
End Try

End Sub
this sub is called form Form2 with the following code:

exitvar = DataGridView1.R ows(e.RowIndex) .Cells(0).Value
Dim ff As New Form1
ff.BringToFront ()
ff.soumavez(exi tvar)

PROBLEM:

if i dont put the codeline "MessageBox.Sho w(varin)", occurs the error at
line "pubmapobj = mgmap.getMapLay er("SIG").getMa pObject(varin)" .
If i put the message "MessageBox.Sho w(varin)", occurs the error at line
"mgmap.getSelec tion().addObjec tsEx(pubmapobje ctos, False)".

the test that u say to do (call the sub from a buttonclick within Form1)
occurs with NO Error!!!!

Thanks

"Daniel Bloch" wrote:

Daniel Bloch schrieb:

What I see is that you do not show the form BringToFront does not make
a control a top-level control, and it does not raise the Paint event.
>
So with the knowledge of the last post, try following
>
- Check, if you can run the sub from form2 alone. Implement a button to
show what you want and make a test like this.
- If this does not work, first correct the sub until you are able to
let it run.
- After that, first show the new form and then let sub run from
form1...
>
Daniel

Sorry, I did a mistake and mixed form1 and form2 :)

[rowe_newsgroups]

Thanks for coming to my rescue here Ghost, with no experience using
Mapguide (and not having it's SDK) I was getting in over my head!

Thanks,

Seth Rowe

GhostInAK wrote:

Hello rowe_newsgroups ,

Your solutuion would not work. MGMapControl is the namespace.. MGMapLayer
is the type. getMapObject is not static (shared).
pubvar2 (GEEZ! Use some better freakin names next time wouldja, OP!) is
supposed to grab a reference to a specific map layer.

You are correct in that the OP is trying to use an object that is null.

OP: Check your MWF, make sure you have a layer actually called "SIG". Also,
ZoomSelected is a terrible way to get to an object. First, the selection
will only succeed if the object is visible at your current zoom scale. Second,
MapGuide is notorious for busystate collisions.

-Boo

Hmm. The "object reference not set to an instance of an object"
exception is raised when you try to use an object that doesn't exist
yet, like if you left out the New keyword. However, everything looks
alright to me. The only thing I would try (outside of praying that
someone else happens on this thread and sees what we're missing!) is
to change this line:

pubmapobj = pubvar2.getMapO bject(varin)

To this:

pubmapobj = MGMapControl.MG MapLayer.getMap Object(varin)

That will take the pubvar2 variable out of the equation. Note, you may
also try throwing the "New" keyword into that line, I'm not sure if
you do or don't need it.

Hope that helps,

Seth Rowe

vitorjol wrote:

Yes....im portuguese....b ut I love America!!!!!

i forgot to tell U the line with the problem!!!Sorry

So, the problem "object reference not set to an instance of an
object" occurs in the line >>pubmapobj = pubvar2.getMapO bject(varin)

Thanks

"rowe_newsgroup s" wrote:

ok....the name "soumavez" its a name that i called to the Sub...End
Sub.

It looked like a foreign langauge to me (is it?), so I was just
making sure it was a protected keyword in a foreign language edition
of visual studio.

Anyways, I have to apologize - my "visual" debugging skills must be
lacking today, as I still don't see anything obviously wrong. Which
line of the code raises the exception?

Thanks,

Seth Rowe

vitorjol wrote:

i put here the code of Sub(its about the Mapguide ActiveX to show a
map in VB). I'll send there to Sub in the other form the id of a
polygon on the map, and then the Sub localize the polygon and zoom
the place!!!

Code of the Sub "soumavez" in the Form1:

Public Sub soumavez(ByVal varin As Integer)
' --->"varin" its the var that i send from Form2!!!
' --->"mgmap" its the name of the control (mapguide activex)
Try
Dim pubmapsel As MGMapControl.MG Selection
Dim pubvar2 As MGMapControl.MG MapLayer
Dim pubmapobjectos As MGMapControl.MG Collection
Dim pubmapobj As MGMapControl.MG MapObject
pubmapsel = mgmap.getSelect ion()
pubvar2 = mgmap.getMapLay er("SIG")
pubmapobjecto s = mgmap.createObj ect("MGCollecti on")
pubmapobj = pubvar2.getMapO bject(varin)
pubmapobjecto s.add(pubmapobj )
pubmapsel.add ObjectsEx(pubma pobjectos, False)
mgmap.zoomSel ected()
mgmap.zoomSca le(mgmap.getLat (), mgmap.getLon(), 1500)
mgmap.refresh ()
Catch ex As Exception
MessageBox.Sh ow(ex.Message, "Erro", MessageBoxButto ns.OK,
MessageBoxIco n.Error)
End Try
End Sub
"rowe_newsgro ups" wrote:

Looks like it should work, when you step through the code where
does the exception occur? If the error occurs in somewhere other
than this sub please post that code too. Also what does "soumavez"
mean?

Thanks,

Seth Rowe

vitorjol wrote:

Here is the code:
>
' the code in form2
Private Sub DataGridView1_R owHeaderMouseCl ick(ByVal sender As
Object, ByVal
e As System.Windows. Forms.DataGridV iewCellMouseEve ntArgs) Handles
DataGridVie w1.RowHeaderMou seClick
dim exitvar as Integer
exitvar = DataGridView1.R ows(e.RowIndex) .Cells(0).Value
Dim ff As New Form1
ff.BringToF ront()
ff.soumavez (exitvar) ' this is the call to the sub in Form1
End Sub
"rowe_newsg roups" wrote:
>
>Please post the code that calls the sub.
>>
>Thanks,
>>
>Seth Rowe
>>
>vitorjol wrote:
>>
>>Hello.
>>>
>>I have 2 forms (Form1 and Form2). When i call the Sub placed in
>>form1 from
>>form2, i get the error "object reference not set to an instance
>>of an object"
>>!
>>What can i do to solve the problem?
>>Thanks
>>>

[GhostInAK]

Hello rowe_newsgroups ,

I envy you, Seth. I have to use the abismal peice of crap every day.

-Boo

Thanks for coming to my rescue here Ghost, with no experience using
Mapguide (and not having it's SDK) I was getting in over my head!

Thanks,

Seth Rowe

GhostInAK wrote:

>Hello rowe_newsgroups ,

Your solutuion would not work. MGMapControl is the namespace..
MGMapLayer
is the type. getMapObject is not static (shared).
pubvar2 (GEEZ! Use some better freakin names next time wouldja, OP!)
is
supposed to grab a reference to a specific map layer.
You are correct in that the OP is trying to use an object that is
null.

OP: Check your MWF, make sure you have a layer actually called
"SIG". Also,
ZoomSelected is a terrible way to get to an object. First, the
selection
will only succeed if the object is visible at your current zoom
scale. Second,
MapGuide is notorious for busystate collisions.
-Boo

>>Hmm. The "object reference not set to an instance of an object"
exception is raised when you try to use an object that doesn't exist
yet, like if you left out the New keyword. However, everything looks
alright to me. The only thing I would try (outside of praying that
someone else happens on this thread and sees what we're missing!) is
to change this line:

pubmapobj = pubvar2.getMapO bject(varin)

To this:

pubmapobj = MGMapControl.MG MapLayer.getMap Object(varin)

That will take the pubvar2 variable out of the equation. Note, you
may also try throwing the "New" keyword into that line, I'm not
sure if you do or don't need it.

Hope that helps,

Seth Rowe

vitorjol wrote:

Yes....im portuguese....b ut I love America!!!!!

i forgot to tell U the line with the problem!!!Sorry

So, the problem "object reference not set to an instance of an
object" occurs in the line >>pubmapobj =
pubvar2.getM apObject(varin)

Thanks

"rowe_newsgr oups" wrote:

>ok....th e name "soumavez" its a name that i called to the
>Sub...En d Sub.
>>
It looked like a foreign langauge to me (is it?), so I was just
making sure it was a protected keyword in a foreign language
edition of visual studio.
>
Anyways, I have to apologize - my "visual" debugging skills must
be lacking today, as I still don't see anything obviously wrong.
Which line of the code raises the exception?
>
Thanks,
>
Seth Rowe
>
vitorjol wrote:
>
>i put here the code of Sub(its about the Mapguide ActiveX to show
>a map in VB). I'll send there to Sub in the other form the id of
>a polygon on the map, and then the Sub localize the polygon and
>zoom the place!!!
>>
>Code of the Sub "soumavez" in the Form1:
>>
>Public Sub soumavez(ByVal varin As Integer)
>' --->"varin" its the var that i send from Form2!!!
>' --->"mgmap" its the name of the control (mapguide activex)
>Try
>Dim pubmapsel As MGMapControl.MG Selection
>Dim pubvar2 As MGMapControl.MG MapLayer
>Dim pubmapobjectos As MGMapControl.MG Collection
>Dim pubmapobj As MGMapControl.MG MapObject
>pubmapse l = mgmap.getSelect ion()
>pubvar2 = mgmap.getMapLay er("SIG")
>pubmapobje ctos = mgmap.createObj ect("MGCollecti on")
>pubmapob j = pubvar2.getMapO bject(varin)
>pubmapobje ctos.add(pubmap obj)
>pubmapsel. addObjectsEx(pu bmapobjectos, False)
>mgmap.zoom Selected()
>mgmap.zoom Scale(mgmap.get Lat(), mgmap.getLon(), 1500)
>mgmap.refr esh()
>Catch ex As Exception
>MessageBox .Show(ex.Messag e, "Erro", MessageBoxButto ns.OK,
>MessageBox Icon.Error)
>End Try
>End Sub
>"rowe_news groups" wrote:
>>Looks like it should work, when you step through the code where
>>does the exception occur? If the error occurs in somewhere
>>other than this sub please post that code too. Also what does
>>"soumavez " mean?
>>>
>>Thanks,
>>>
>>Seth Rowe
>>>
>>vitorjo l wrote:
>>>
>>>Here is the code:
>>>>
>>>' the code in form2
>>>Privat e Sub DataGridView1_R owHeaderMouseCl ick(ByVal sender As
>>>Object , ByVal
>>>e As System.Windows. Forms.DataGridV iewCellMouseEve ntArgs)
>>>Handle s
>>>DataGrid View1.RowHeader MouseClick
>>>dim exitvar as Integer
>>>exitva r = DataGridView1.R ows(e.RowIndex) .Cells(0).Value
>>>Dim ff As New Form1
>>>ff.Bring ToFront()
>>>ff.souma vez(exitvar) ' this is the call to the sub in Form1
>>>End Sub
>>>"rowe_ne wsgroups" wrote:
>>>>Pleas e post the code that calls the sub.
>>>>>
>>>>Thank s,
>>>>>
>>>>Seth Rowe
>>>>>
>>>>vitorjo l wrote:
>>>>>
>>>>>Hell o.
>>>>>>
>>>>>I have 2 forms (Form1 and Form2). When i call the Sub placed
>>>>>in
>>>>>form 1 from
>>>>>form 2, i get the error "object reference not set to an
>>>>>instan ce
>>>>>of an object"
>>>>>!
>>>>>What can i do to solve the problem?
>>>>>Than ks

[vitorjol]

Can i force the execution of the Button_click located in Form1 from Form2?

i ask this because in Form1, if i execute the sub called from the
button_click everything goes right, but if i call the sub outside the Form1
(Form2) occurs the error!!!

Thanks

"GhostInAK" wrote:

Hello rowe_newsgroups ,

I envy you, Seth. I have to use the abismal peice of crap every day.

-Boo

Thanks for coming to my rescue here Ghost, with no experience using
Mapguide (and not having it's SDK) I was getting in over my head!

Thanks,

Seth Rowe

GhostInAK wrote:

Hello rowe_newsgroups ,

Your solutuion would not work. MGMapControl is the namespace..
MGMapLayer
is the type. getMapObject is not static (shared).
pubvar2 (GEEZ! Use some better freakin names next time wouldja, OP!)
is
supposed to grab a reference to a specific map layer.
You are correct in that the OP is trying to use an object that is
null.

OP: Check your MWF, make sure you have a layer actually called
"SIG". Also,
ZoomSelected is a terrible way to get to an object. First, the
selection
will only succeed if the object is visible at your current zoom
scale. Second,
MapGuide is notorious for busystate collisions.
-Boo

Hmm. The "object reference not set to an instance of an object"
exception is raised when you try to use an object that doesn't exist
yet, like if you left out the New keyword. However, everything looks
alright to me. The only thing I would try (outside of praying that
someone else happens on this thread and sees what we're missing!) is
to change this line:

pubmapobj = pubvar2.getMapO bject(varin)

To this:

pubmapobj = MGMapControl.MG MapLayer.getMap Object(varin)

That will take the pubvar2 variable out of the equation. Note, you
may also try throwing the "New" keyword into that line, I'm not
sure if you do or don't need it.

Hope that helps,

Seth Rowe

vitorjol wrote:

Yes....im portuguese....b ut I love America!!!!!

i forgot to tell U the line with the problem!!!Sorry

So, the problem "object reference not set to an instance of an
object" occurs in the line >>pubmapobj =
pubvar2.getMa pObject(varin)

Thanks

"rowe_newsgro ups" wrote:

ok....the name "soumavez" its a name that i called to the
Sub...End Sub.
>
It looked like a foreign langauge to me (is it?), so I was just
making sure it was a protected keyword in a foreign language
edition of visual studio.

Anyways, I have to apologize - my "visual" debugging skills must
be lacking today, as I still don't see anything obviously wrong.
Which line of the code raises the exception?

Thanks,

Seth Rowe

vitorjol wrote:

i put here the code of Sub(its about the Mapguide ActiveX to show
a map in VB). I'll send there to Sub in the other form the id of
a polygon on the map, and then the Sub localize the polygon and
zoom the place!!!
>
Code of the Sub "soumavez" in the Form1:
>
Public Sub soumavez(ByVal varin As Integer)
' --->"varin" its the var that i send from Form2!!!
' --->"mgmap" its the name of the control (mapguide activex)
Try
Dim pubmapsel As MGMapControl.MG Selection
Dim pubvar2 As MGMapControl.MG MapLayer
Dim pubmapobjectos As MGMapControl.MG Collection
Dim pubmapobj As MGMapControl.MG MapObject
pubmapsel = mgmap.getSelect ion()
pubvar2 = mgmap.getMapLay er("SIG")
pubmapobjec tos = mgmap.createObj ect("MGCollecti on")
pubmapobj = pubvar2.getMapO bject(varin)
pubmapobjec tos.add(pubmapo bj)
pubmapsel.a ddObjectsEx(pub mapobjectos, False)
mgmap.zoomS elected()
mgmap.zoomS cale(mgmap.getL at(), mgmap.getLon(), 1500)
mgmap.refre sh()
Catch ex As Exception
MessageBox. Show(ex.Message , "Erro", MessageBoxButto ns.OK,
MessageBoxI con.Error)
End Try
End Sub
"rowe_newsg roups" wrote:
>Looks like it should work, when you step through the code where
>does the exception occur? If the error occurs in somewhere
>other than this sub please post that code too. Also what does
>"soumave z" mean?
>>
>Thanks,
>>
>Seth Rowe
>>
>vitorjol wrote:
>>
>>Here is the code:
>>>
>>' the code in form2
>>Private Sub DataGridView1_R owHeaderMouseCl ick(ByVal sender As
>>Object, ByVal
>>e As System.Windows. Forms.DataGridV iewCellMouseEve ntArgs)
>>Handles
>>DataGridV iew1.RowHeaderM ouseClick
>>dim exitvar as Integer
>>exitvar = DataGridView1.R ows(e.RowIndex) .Cells(0).Value
>>Dim ff As New Form1
>>ff.BringT oFront()
>>ff.soumav ez(exitvar) ' this is the call to the sub in Form1
>>End Sub
>>"rowe_new sgroups" wrote:
>>>Please post the code that calls the sub.
>>>>
>>>Thanks ,
>>>>
>>>Seth Rowe
>>>>
>>>vitorj ol wrote:
>>>>
>>>>Hello .
>>>>>
>>>>I have 2 forms (Form1 and Form2). When i call the Sub placed
>>>>in
>>>>form1 from
>>>>form2 , i get the error "object reference not set to an
>>>>instanc e
>>>>of an object"
>>>>!
>>>>What can i do to solve the problem?
>>>>Thank s

[Daniel Bloch]

Now, have you tried to first SHOW the document with the command "show"
before let running the sub.

I realy believe that your problem just occurs because there is no valid
form available (because it's not yet shown and has it's window handle)
that can take the form handlings of your map software ...

Daniel

[vitorjol]

i have the form1 and form2 open....i dont have to do the show command to the
Form1...i think!!!!!

"Daniel Bloch" wrote:

Now, have you tried to first SHOW the document with the command "show"
before let running the sub.

I realy believe that your problem just occurs because there is no valid
form available (because it's not yet shown and has it's window handle)
that can take the form handlings of your map software ...

Daniel

[Daniel Bloch]

Have you tried?

Sometimes, software development is not about thinking but about trying.
So give it a try and place a ".show" instead of ".bringtofr ont" and
check out, what happens.

Daniel

[vitorjol]

it opens again the form1....i dont want this, and dont work anyway!!!
i think that i solved the problem. In form1 i open the form2 with the
command showdialog...ju st this!!!

"Daniel Bloch" wrote:

Have you tried?

Sometimes, software development is not about thinking but about trying.
So give it a try and place a ".show" instead of ".bringtofr ont" and
check out, what happens.

Daniel