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Where can i find information on writing a setup project for my app that uses SQL server and crystal reports? I wrote one but when i install on another computer, the crystal report does not load and there is no connection between databases.
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Prototypical Code (class/method structure omitted):
dim FG as ComObject
dim someString as String = "Some String"
FG = new ComObject
Try
FG.someMethod(someString)
Catch ex as Exception
msgbox("Error: " & ex.message & vbCrLf & "(FG is Nothing): " & (fg Is Nothing).toString) & vbcrlf & "(someString is Nothing): " & (someString Is Nothing).toString)
End Try
-------
The output I get is:
Error: Object reference not set to an instance of an object.
(FG Is Nothing): False
(someString Is Nothing): False
I was under the impression that if the "object reference [is] not set to an instance of an object", then that object "Is Nothing" should return True.
Can someone set me straight, please, I'm going nuts trying to figure this one out.
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Hi,
Is it possible that inside FG.SomeMethod, something is trying to reference a null object?
Can you step into the FG.SomeMethod code and see if it is happening INSIDE there?
(side note, the first instance of "(fg Is Nothing).toString)" in your messagebox string should not have the paren at the end) - I just know because I tried to run the code.
Thanks,
-Len Miller
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe."
-Abraham Lincoln
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Good catch on the msgbox string - I missed that.
FG is a 3rd party COM object, so anything is possible inside it. Unfortunately, that also means I can't debug it.
But it sounds like I'm not going nuts - if FG is "not set to an instance of an object" then (FG Is Nothing) would evaluate True.
Thanks for the help.
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Hmm. Too bad you can't debug the method.
What I would do is check the docs of FG & FG.SomeMethod.
Maybe the objects expects that you have already set a property to some object that it is trying to use. Or, maybe it expects that you may have already set some objects that it needs during creation.
Like this:
Dim FG as new ComObject(neededObject)
Or this
FG.NeededObject = neededObject
Maybe THEN you can run
FG.SomeMethod
???
Just a thought...
Good luck
Thanks,
-Len Miller
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe."
-Abraham Lincoln
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My best guess is that there is a variable in FG.someMethod that is causing the problem. Have you tried running your code in debug mode then stepping through line by line with the F11 key till you get to the line causing the error?
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Unfortunately FG is a 3rd party COM object, so I can't debug it.
But it sounds like I'm not going nuts - if FG is "not set to an instance of an object" then (FG Is Nothing) would evaluate True.
Thanks for the help.
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How to calculate the muliplication of 2 fields to next field
on the .NET data grid but run time? If I move up,down,left,right on the grid,it must calculate whenevere change takes place on the grid cell.
e.g There are 3 columns Units,Unit price and Total on the grid. I want to get Total = Units*UnitPrice. I have written some lines for this purpose under the CurrentCellChanged Event but its working in the same row. but I need If I edit the value of Units Column and go to Column other than these 3 by key down or key up.Its working for KeyRight and KeyLeft.
Here is the code that I have Written
dgOrderDetail is the Name of Data Grid.
Private Sub dgOrderDetail_CurrentCellChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles dgOrderDetail.CurrentCellChanged
If dgOrderDetail.CurrentRowIndex >= 0 Then
If Not IsDBNull(dgOrderDetail.Item(dgOrderDetail.CurrentRowIndex, 10)) And Not IsDBNull(dgOrderDetail.Item(dgOrderDetail.CurrentRowIndex, 11)) Then
dgOrderDetail.Item(dgOrderDetail.CurrentRowIndex, 12) = CInt(dgOrderDetail.Item(dgOrderDetail.CurrentRowIndex, 10)) * CInt(dgOrderDetail.Item(dgOrderDetail.CurrentRowIndex, 11))
End If
End If
I am much trapped in this probelm cuz I have to do it on urgent basis.
Plz help me in this regard
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See DataColumn.Expression in MSDN Help.
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Hey, im trying to get a powerpoint presentation to open in VB, so that it runs but the user cant edit it or stuff anything up. Any help would be appreciated. Thanks.
Court
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how to design word document dynamically using microsoft.office.interop assembly?
as well require api refereces for that?
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hi coders,
i'm perplexed with VB .NET DataGrid...
i can't find out how it is possible to remove a selected row from that control.
imagine we have a button "suppress a line" and the DataGrid from which the user is able to select a row. what i want is when the button is clicked, i'd like to suppress the selected item from the DGrid...
does anyone know how to do that ?
thanx in advance
TOXCCT >>> GEII power
[toxcct][VisualCalc]
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Hi,
You cannot directly delete/suppress a row from a datagrid.
You have to manipulat its datasource and then reassign the datasource.
eg:
dim dtable as new datatable
dtable = grid.datasource.
dtable.rows.removeat(index) (Use some logic here to pass the row no. i.e. the index)
reassign the table.
grid.datasource = dtable.
do let me know if this helps.
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genius123 wrote:
You cannot directly delete/suppress a row from a datagrid.
You have to manipulat its datasource and then reassign the datasource.
yes, of course, but i didn't know how to catch the index of the selected lineto delete the associated item in my ArrayList...
so, thank you for your answer 
TOXCCT >>> GEII power
[toxcct][VisualCalc]
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Catching the rowindex is pretty easy.
index = datagrid.currentrowindex()
if ur using a dataset, delete the row using
ds.Tables("tablename").Rows.RemoveAt(index)
or a datatable
then
dtable.rows.removeat(index)
and plz try elaborating problems a bit to get exact answers
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Hi,
I have created a Windows Service in VB.NET. I need to install it another system. Pls tell me how to install it .
Thank You
Mahesh
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Thank you very much. I have got some idea, i will try and then get back to you.
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You can also use installutil.exe to install your service.
installutil nameofyourapp.exe
More info here :
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cptools/html/cpconinstallerutilityinstallutilexe.asp
sebastien.lachance.blogspot.com
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from vb .net solution, I import some functions from c dll which is created using visual studio 6.0. I import by declare Private Declare sub subName lib "capp.dll"...
Is it possible to debug that capp.dll? when I tried to debug, I set a break point at the import function and did a step in, but it just step over the function. Any idea will be appreciated.
Thanks.
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Compile your application in VB.NET. Use Visual Studio 6 IDE to debug the dll source code, using the compiled NET exe as the calling application.
Robert
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We have one VB.net windows based application.It's installed on about 10 client machines.
Every time when we make any changes then we have to reinstall the application on each machine.
Can we add functionality in our application that if there is any modifcation in application then apllication installed on client machine check for update/changes and download the copy from server and installed it automatically.
I have seen this feature in most of the windows prodct but don't know how to add it.
Arvind Malik
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I need to capture all the content of a non visible or partially visible window.
BitBlt works fine on the visible part of the window. Does anyone know how to capture the full content of the window when it is not visible and to display it at a smaller size on a new window.
Image capture is the fundamental problem. Thanks for your help.
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