Visual Basic

2-Nov-06 12:57

Ahh!

It happened again, I was coding and I try to debug and I get an error saying:

<br />
InvalidOperation Exception was unhandled<br />
<br />
An error occurred creating the form. See Exception.InnerException for details.  The error is: Object reference not set to an instance of an object.<br />

I undid everything that I typed after the last debug and it still freaked out. Everytime this happens I have to start over on my project! What happened!

Please help! Thank you!

Dave Kreskowiak2-Nov-06 15:50

2-Nov-06 15:50

There's really no way for us to tell what happened since we know nothing of your project or the line that the error occurs on. Basically, it's saying that you're trying to call a method or use a property of an object when you don't even have an instance of it to call a method on.

Click the "Show all files" button in the Solution Explorer and open the Designer file for the form that you're having the problem with. You should be able to find the problem code in there.

Dave Kreskowiak
Microsoft MVP - Visual Basic

UltraCoder2-Nov-06 16:14

2-Nov-06 16:14

I just get an error, that's all. It doesn't say which line.

And, I don't see anything in the Designer file!

UltraCoder2-Nov-06 16:25

2-Nov-06 16:25

Ok, I found the problem, something is wrong with this variable:

Private PrintFont As New Font(RichTextBox.Font, RichTextBox.Font.Size)

The above code sets the font used when printing a document.

If you can please tell me why this variable caused an error, I would appreciate it.

Thanks for your help!

Dave Sexton2-Nov-06 19:36

Dave Sexton

2-Nov-06 19:36

It won't run outside of a method. Put it in the event handler that handles the printing as

Dim PrintFont As New Font(RichTextBox.Font, RichTextBox.Font.Size)

I'm not sure of why the error occurs, I think it has to do with the InitializeComponent() call of the form - you're getting a NullReferenceException as the font has been declared before the
RichTextBox has and the compiler doesn't "think" the RichTextBox exists yet.

At least that's what I think, I stand under correction but it makes sense.

Dave Kreskowiak3-Nov-06 1:30

3-Nov-06 1:30

You used a lousy name for your RichTextBox. Don't use the name of a class as an instance variable of that same class. Rename your RichTextBox to something like myRichTextBox or NarrativeRTB or something useful. Do NOT use existing class names.

Dave Kreskowiak
Microsoft MVP - Visual Basic

UltraCoder3-Nov-06 14:02

3-Nov-06 14:02

It's called "Example", dude! I don't use generic terms like that when I'm programming! Laugh | :laugh:

Dave Kreskowiak3-Nov-06 18:27

Calling an excel function

3-Nov-06 18:27

BS examples like that get you the answers I gave you. The proper way to do it is to copy and paste your REAL code. Don't use "examples" and don't just retype what you think is in your source files.

According to the error message, whatever variable you used for RichTextBox, doesn't point to an instance of anything. It's like you did this:

Dim rtb As RichTextBox

and tried to call a method on rtb. It'll give to the object instance error you got.

Dave Kreskowiak
Microsoft MVP - Visual Basic

Mark062-Nov-06 12:31

Mark06

2-Nov-06 12:31

Hi,
I have an addin module plugged into Excel, which exposes some functions to do stuff.
Im need to call those function through some VB.Net code, but its failing without much help. Its a generic ole error returned, nothing useful at all.
If the workbook contains a function/macro, I can call that easy using the Excel.ExecuteExcel4Macro() line. But this doesnt seem to work for addins.

My code looks like this:

 Dim ex As New Microsoft.Office.Interop.Excel.Application()<br />
...<br />
Do stuff<br />
...<br />
       ex.ExecuteExcel4Macro("RUN(""ConvertData"")")<br />
       ex.Visible = True<br />
<br />

The VB.Net program opens Excel as a COM object, post some data to it, then needs to call the functions in the addin.

Anyone know of the correct syntax, or can spot where Ive gone wrong?

Mark

Re: Calling an excel function

OldWarhorse2-Nov-06 16:34

OldWarhorse

2-Nov-06 16:34

Mark,
Try this:

http://support.microsoft.com/kb/198571[^]

The article is for Access 2000, but the code would be very similar.
(Without the Set statements of course.)

objExcel.Application.Run("atpvbaen.xla!lcm", 5, 2)

Dave

VBA in Excel - Passing name to function

TheJudeDude2-Nov-06 10:44

TheJudeDude

2-Nov-06 10:44

I want to pass the name of a worksheet to the Sheets.Select(name) function. I defined a public variable in the worksheet declaration and assigned the name to the sheet I want to select. I am getting an error subscript out of range.
Any suggestions. (is this possible?)

Jude

Re: VBA in Excel - Passing name to function

OldWarhorse2-Nov-06 15:26

OldWarhorse

2-Nov-06 15:26

TheJudeDude wrote:
(is this possible?)

Sure.

Make sure the variable actually contains the name, make sure it is spelled correctly, and be specific as to which WORKBOOK you are referencing the Sheets collection in.

But do you want to select the sheet or replace ranges on it?
If you want to select the sheet, it's like this:

Ex.

Public Sub TestWBname()

Dim wb As Workbook
Dim wbName As String

Application.Workbooks("Book1").Activate

Set wb = Application.ActiveWorkbook

wbName = "mySheet"

wb.Sheets(wbName).Select

End Sub

There's a Sheets.Select([Replace]) function, which uses the syntax you specified above, but which I don't think is what you want.

Re: VBA in Excel - Passing name to function

Dave Kreskowiak2-Nov-06 15:42

Multiple SiteMapProviders

2-Nov-06 15:42

You dont give the sheet name to the Select method. You give it to the Items property of the Sheets collection, which will return a Worksheet object, on which you call the Select method.

Sheets("Sheetname").Select()

Dave Kreskowiak
Microsoft MVP - Visual Basic

nlindley72-Nov-06 10:16

nlindley7

2-Nov-06 10:16

1) I know this is an ASP.NET question, but the answer rate in that particulary forum is far behind this forum.

Q)The index page on a website i'm designing contains a menu for, well, navigation. My question is what is the best route to dynamically set the menu's SiteMapProvider to the correct provider based on a users login credentials.

Nathan Lindley

Insert/Overwrite

UltraCoder2-Nov-06 9:04

2-Nov-06 9:04

I'm trying to detect whether someone has Insert on/off, but the code I'm using isn't working.

<br />
If Keys.Insert = True Then<br />
  Label.Text = "Overwrite"<br />
End If<br />
If Keys.Insert = False Then<br />
   Label.Text = "Insert"<br />
End If<br />

Please help. Thank you!

Guffa2-Nov-06 9:24

Guffa

2-Nov-06 9:24

Standard question #1:
What do you mean by "not working"?

Standard question #2:
What error message do you get?

Of course it isn't working. Keys is a enumeration that contains values for key codes. The value Keys.Insert is a constant value which can never be True, neither False, at it is not a boolean value.

You should get an error message from the compiler, saying that the value of the condition could never change, as you are comparing two constant values.

---
b { font-weight: normal; }

UltraCoder2-Nov-06 9:40

2-Nov-06 9:40

I do not get an error message or compiler error, it just doesn't change the label's text like I want it to.

And, what should I use instead of Keys or Keys.Insert?

nlarson112-Nov-06 10:24

nlarson11

2-Nov-06 10:24

I don't think there is a true dotnet way.

use this api

Private Declare Auto Function GetKeyState Lib "user32.dll" ( _
ByVal nVirtKey As VirtualKey _
) As Boolean

google it to find out how to use it...

UltraCoder2-Nov-06 10:37

2-Nov-06 10:37

Sorry, doesn't work. Thanks anyway though!

nlarson112-Nov-06 10:56

nlarson11

2-Nov-06 10:56

The api code definition was written Pre-dotnet so it uses long and integer. you need to change these to the new dotnet equivalents to int32 / int16.

just tested the below code in 2005 and it works fine:

Public Declare Function GetKeyState Lib "user32" Alias "GetKeyState" (ByVal nVirtKey As Int32) As Int16

private sub CheckInsertStatus()

if getkeystate(keys.insert)=0 then
msgbox "overwrite"
else
msgbox "insert"
end if

end sub

UltraCoder2-Nov-06 11:05

2-Nov-06 11:05

It works! Thanks a lot dude! Smile | :)