How can you set a function optional argument to null? For example, I want to set the optional argument intCode equal to Null. These arguments are used to send to a stored procedure as parameters.
Public Function pubfnc_SetCommentCode(ByVal strFieldName As String, ByVal lngResultID As Int32, Optional ByVal intCode As Int32 = DBNull.Value) As String
I think this is a pretty basic question, but I just want to clarify. If I have a variable with a null value, and pass it as a parameter that is optional, will the parameter get the null value, or the default value?
dim str As String = "foo"
dim obj As Object
//call 1
[code].....
I just got upgraded from VB6.0 to VB2010. I'm trying to move some of my program functions over and I'm getting an error on the ones where I use optional... Public Function GetFolder(ByRef FTT As String, Optional InitFile As String)
I get the error at the end of the line, after the close par...the error is "optional parameters must specify a default value".
I am getting this error when debugging a VB application. The method that is being called when I get this does not have any arguments. Definitions in code are as follows with names changed to protect the guilty
[Code]...
The question is, if the method is not defined to accept argments, then why am I having a debug assertion while debugging that says that the arguments are not optional?
I have an Image.OCX which is build on 2008. This is used by VB Application.Many OCX methods are not used in Application. I want to delete unused method from OCX.Step for method deletion.
Delete exists Method from .ODL File i.e //[id(181), helpcontext(11)] long CreateImage(ID id);.
Delete
CreateImage same function . Delete //DISP_FUNCTION(CImageCtrl, "CreateImage", CreateImage, VT_I4) from Ctrl.cpp.
Delete interface ID from AFX_DISP_ID.
[code]....
Following Error Message display "Run Tim error '449':Argument not optional."
let me know is that possible to delete exist method from OCX and How?
I have a function that has an optional dictionary argument. Since it's optional, it needs a default value, and I'd like to set it to an empty dictionary instead of Nothing. How do I go about that?
View 2 RepliesI want to specify an List(Of String) as an Optional function argument. But i am unable to initialize it in the function declaration.
View 1 RepliesI have an Excel VBA function that takes a number of optional parameters, including an optional Range:
Function DazBeta(A As Range, Z As Range, _
B As Integer, _
Optional Freq As Integer = 1, _
Optional c As Double = 0, _
Optional r As Range, _
Optional Pct As Boolean = True, _
Optional Label As Integer = 1)
I am translating to VB.NET, and it's the optional Range that is giving me grief because VB.NET does allow optional Ranges. Or rather, optional parameters must provide a default value. What is the recommended way to change the VB.NET function signature so that the code is callable from an Excel cell as a UDF? (The VB.NET implements a UDF, the assembly is registered as a COM server, and the Excel spreadsheet is told of this server and type library, allowing the VB.NET code to be called from an Excel spreadsheet cell.) I have other compilation problems, so I have not been able to explore this. I am thinking that accepting an optional Object (default value Nothing) might work and then I could cast the Object to a Range. Alternatively, if there were a default value that could be specified with an optional Range, that would work, too.
I am trying to have an optional Date value in one of my sub but since you cant set Date to nothing, this doesn't work. And i cant set it to the Date.minvalue inline.
Private Sub abc (ByVal A As String, Optional ByVal B As Date = Nothing)
End Sub
So, i went and set it to some date in the past.
Private Sub abc (ByVal A As String, Optional ByVal B As Date = #1/1/2001#)
End Sub
what would be the proper way to handle the default value for an optional Date?
I tried DbNull.Value but no luck. How do I assign a default value as null to a string parameter that is null in VB.NET? Its litte strange to see that VB does not have anything like plain null as most of the other languages do. Also what is the difference between null and DbNull and Nothing.
View 3 RepliesPublic Function Foo(ByRef a As AClass, _
Optional ByRef b As BClass = Nothing, _
Optional ByRef c As CClass = Nothing) As XClass
Error : Optional parameters must specify a default value.
I am hardcoding an insert statement to a database, based on certain details a user enters into a windows form. The form has a few textbox and datetimepicker controls for the purpose. This form enters a single row in a single table in the database.The table has a few possible null columns defined, in those cases where the user does not have any data for those columns at that particular time.
I have to provide controls for passing data to those null columns nevertheless. In my case, I have two such columns that accept null values, and two corresponding controls - a textbox and a datetimepicker. The datetimepicker has a checkbox added to it so that if it is supposed to be null it doesn't pass the default current date value, and remains unchecked to explicitly specify that it is supposed to be null. By default it is unchecked.
My code is structured as follows:
Form1:
'the sub referenced here resides in a dll file in my dataaccesslayer code, and in my actual example is referenced properly.
'I have shortened the code here for simplicity
[code]....
Now it gives me an error whenever the code comes to the executenonquery(), and says something to the tune of "SqlDateTimeOverflow. Must be between 1/1/1753 12:00:00 AM and 12/31/9999 11:59:59 PM."
I think the value of 'Nothing' from the subprocedure's paramter is not being assigned to the sqlcommand's parameter as a database NULL, which is what I need to pass to the database.I know instead of using optional parameters I can easily create overloaded subprocedures where one sub allows not passing values where the column(s) is supposed to null and other overloaded subs permit combinations of which column(s) are null or not. But it is simple as long as there is just one, or at the most two null columns in a table. If I have dozens of null values in a table that the user can choose to enter or not in a data entry form?
I have a problem during defining a Sub routine in VB.Net. I am defining a sub routine which is as under
Private Sub ActivateControls(rdbutton as RadioButton, Optional txt as Textbox, Optional txt2 as Textbox)
End sub
When I call this sub routine It gives me the Error that Each Optional Parameter must specify a default value. So, Here I can't understand that what can be the default value of a textbox. What default value I can use here to remove this error.
My problem is this (apologies if this is a little long ... hang in there):I can define a function in VB.NET with optional parameters that wraps a SQL procedure:
Sub Test(OptionalByVal Arg1 As Integer _
Optional ByVal Arg2 As Integer _
Optional ByVal Arg3 As Integer
[code].....
I can't get to pass structure as argument through subs/functions in different files of single vbnet project like I use to in earlier MS basic versions.[code]File "mysetup.dat" is reachable and data is saved correctly what I can see with HxD.But read part seem's to not work as expected. Please any help on reliable passing structure as argument without too much public elements based on upper example.
View 1 RepliesI am working on a vb windows form application with several connected forms. Its used to manipulate a MySQL database. One of the sub-forms has the following code snippet:
[Code]...
Recently, I just helping my friend for developing game private server, in Game Client there are 3 application is needed, its is a patcher, launcher, and main exe, my friend use open source (C++ language) application for the patcher, the patcher is work nicely, and the launcher is program that launch main exe, its using launcher because main exe is need some argument to run, the launcher is created by me.The problem is the user can be run game directly without opening the patcher, so I want to change default command line (usually "0" / "1") in launcher to 3, and I have the trap if user open directly the launcher
If My.Application.CommandLineArgs.Item(0) = "3" Then
MsgBox("Please Run Patcher to proceed the game!")
End
[code]....
I have a class and method exposed to a client asp.net app. The class looks like
<DataContract()> _
Public Class Class1
Private v_string As String
Private v_integer As Integer
[code]....
The method is declared as
<OperationContract()> _
Function GetStuff(ByVal bar As Class1) As String
In the client code I create an instance of Class1 and set the values for v_string and v_integer, but using Wireshark to look at the xml being sent to the server only a value for v_string is being sent as part of Class1. I'm guessing this is because it considers the value of v_integer to be null/not set. Here is an example of the client code.
Dim MyService as New Service1.ServiceClient
Dim test as New Service1.Class1
test.P_integer = 1
[code]....
how different types are passed/used since Integer is a intergral type and String is a class, but can't seem to work out what to do to fix the problem.
How to get a nice pop-up of default values for a function? Here's what I mean: I assume it's an enum or object but I'm not sure where to define it or what exactly it would be called.
View 4 Replies[code]Is j passed as value ByVal or by reference ByRef?Or does it depends of the data type? What if I have a complex object passed as the value?
View 2 Repliesi have a stored procedure to insert data into table create procedure insertdata
[Code]...
how to change calender default value to null?
View 1 Replies[Code]...
'column' argument cannot be null. Parameter name: column
I have the following
If Trim(txtConfirmationDate.Text) <> "" Then
sqlinsert2.Parameters.AddWithValue("@CONFIRMDATE", CDate(txtConfirmationDate.Text))
Else
sqlinsert2.Parameters.AddWithValue("@CONFIRMDATE", VB.vbNull)
End If
Unfortunately, it writes "01/01/1900" to the database. How do I get it to just leave the field as NULL?
I have a form that has several controls, most of them are textboxs. All controls are binded to a bindingsource. The controls that always have values, they are displayed correctly, but the others ones that have null values in the data source, the default null value doesn't show up. This problem it's driving me crazy... There must be something that i'm missing. Some of the code that i had used with no luck:
[Code]...
What I am trying to do is have a class where the functions of the same name are both instance functions and shared functions.
Public Shared Function Get...(byval xx as xx)
and
Public Function Get...
The Public Function uses a Property xx created in the constructor, whereas the Shared Function has the parameters (byval xx as xx).
If i didn't place any date in the textbox ,system is capturing 1/1/1900 by default insted of Null.How can i get rid of this.
[Code]...
I made this procedure re-use a select query:
[code..]
And I use it like this if I would want the selected value placed in a textbox and it works fine
[code...]
However if I want the value to be passed in a string like so:
[code...]
The string ends up having an empty string value. How do I assign the value I queried to that String?
1) Is it possible to access the Excel mathematical functions without actually opening Excel?
I was thinking of through a DLL WinAPI call or maybe a delegate function or smaller program?
2) Does anyone know of a MS link or area that gives instruction on "how to" use every function of every Windows DLL at all?
Or for all those that Microsoft have chosen to document online at least.
While converting types, I have found myself using both VB functions and BCL Convert.To* methods.
E.g.)
Cstr() vs. Convert.ToString()
CInt() vs. Convert.ToInt32()
CDbl() vs. Convert.ToInt64()
etc...
Are there any subtle differences that should be noted?
