Declaring Optional Controls - Parameter Must Specify Default Value
Jul 28, 2010
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.
View 6 Replies
ADVERTISEMENT
Sep 22, 2010
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].....
View 1 Replies
Sep 18, 2009
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].....
View 7 Replies
Oct 19, 2011
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".
View 3 Replies
Mar 6, 2010
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?
View 3 Replies
Mar 14, 2012
How can i create a optional parameter in C# as we create in VB.Net
Public Sub Demo(ByVal a As Integer,Optional ByVal b as integer=3)
End Sub
I want to declare this in C#
[code].....
View 2 Replies
Sep 25, 2009
Is it possible to have an optional parameter of the type list?Ex.
Private Function TestFunction(Optional ByRef MyList As List(Of Double))
The real problem is giving the list a default value. When dimming a new list, you can use the code below to give it a starting value:
Dim MyList As New List(Of Double)(New Double() {1, 2, 3, 4, 5})
But even after trying many variations of the above code, I cannot get it to work as an optional parameter.
View 16 Replies
Nov 1, 2010
Is there a way to pass an optional parameter to a webservice, instead of having to overload the method?If the webservice user is accessing the webservice directly, I want to do ActionA, if the user is accessing the webservice through my web interface, I want to do ActionA + ActionB.
View 1 Replies
Nov 3, 2010
how can use color as an optional parameter in a sub/function?This doesn't work.
Code:
Public Sub WriteLog(ByVal sText As String, Optional ByVal lColor As Color = Color.Blue)
'Code
End Sub
View 5 Replies
May 27, 2010
I have come across something confusing or potentially a bug in Visual Studio 2010 when defining an interface in my VB application: When defining an interface method with a default parameter of type Double, using the Double.NaN constant as the default value causes the code editor/intellisense/precompiler some issues.The following code underlines "INaNTest" and "INaNTest.DoSomething" claiming that 'DoSomething' cannot implement 'DoSomething' because there is no matching sub on interface 'INaNTest':
[code]...
where now "NaN" has been divorced from the "Double." prefix and underlined ('NaN' is not declared. It may be inaccessible due to its protection level.) The code editor has inserted invalid code again.Is there a correct solution to using Double.NaN as the default value for a method as defined on an interface, in VB.net, or is there a fundamental reason why this is impossible?
View 2 Replies
Jan 21, 2011
Public 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.
View 2 Replies
Mar 22, 2011
I have an object, called 'PERSON' This person object has a title, firstName & Surname property as well as many other which are at the moment irrelevant. It also has a read only property called Fullname which concatenates the two or three parameters mentioned above depending on an optional parameter 'withTitles' passed over when you call PERSON.FULLNAME
PERSON.FULLNAME(true) <- Will add titles if there are any
PERSON.FULLNAME(false) <- Will give the name without the title
Public ReadOnly Property FullName(Optional ByVal withTitle As Boolean = False) As String
[Code]...
I get an error: PERSON does not contain a property of 'FullName'. If I change this to any other property that does not take a parameter it works as expected. Now I'm guessing that the binding procedure can't handle optional or mandatory parameters for object properties, is this right? Is there a better way to do it? I thought about looping through the collection to add them manually but that kinda defeats the object of DataBinding!
View 1 Replies
Apr 19, 2012
I have traditionally coded empty strings like this "", but for a couple of years now, I have been using String.Empty.I also normally never use optional parameters, but I'm refactoring a solution that's tied into my ERP, and I don't want to break anything. One of the changes was to add a parameter to proc, which pushes a new parameter into the method from which it is called. I coded it like this:
Optional BackReferenceID As String = String.Empty
But I got a syntax error "Constant expression is required." I guess String.Empty is non-deterministic??? Anyway, it seems like a bug. The workaround is of course to use double quotes.
View 1 Replies
Aug 4, 2011
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
View 13 Replies
Nov 13, 2011
I tried the following, but i get the error
constant expression is required
Public Sub ExampleSub(ByVal Test as string,
Optional ByVal fromDate As System.Nullable(Of DateTime) = Date.Today)
'A Great sub!
[Code].....
View 3 Replies
Apr 10, 2009
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?
View 7 Replies
Jan 18, 2010
How can I create a nullable numeric optional parameter in VB.NET?
View 3 Replies
Apr 26, 2010
I have created my own ListViewItem class, and added some custom properties to it of attributes. What I have at the moment is a tooltip which shows all of those custom properties (about 18 of them).What I want to be able to do is if multiple are selected, to show a tooltip, but if a property (say Title) for all of them is "My Title" it will show that, otherwise if they are different, I would like it to show "VARIES"Is there a way of declaring a parameter in my function and return a value? [code]
View 1 Replies
Aug 24, 2009
If I comment the paramList line, I see the "CreateDetailedReport()" message box, but if I uncomment it, the message box never appears - there are no errors or anything, it simply seems to not run the function. On my development machine it works properly, but this odd behavior is seen on the target machine.
[code...]
Any reason why this would make the line before it not run - even without producing an error,o
crashing, or something?
View 1 Replies
Mar 8, 2012
Which of the following is more readable and preferable?
This, where the default value is assigned in the declaration:
Dim isLastWeekOfPeriod As Boolean = False
If periodInfo.WeekCount = weekInfo.Week Then
isLastWeekOfPeriod = True
[Code].....
View 1 Replies
Jan 20, 2010
Am in the middle of a project and randomnly VWD has stopped recognising new Server controls in the .vb code. For instance if I add a label and then try to set the text in the code behind VWD doesn't recognise the control ID. Can't figure out why it's not working. The label isn't inside any datacontrols or anything with any special conditions. It's just a regular Label on the page.
View 1 Replies
Dec 20, 2011
I am using Stanav's PdfManipulation2.AddImageToPage(..., Pages) for iTextSharp library (v5.1.3) and was not able to add the image to specific pages: e.g. to add to only page 1 and 3 of a five pages PDF
Dim Pages() As Integer
Pages = New Integer() {1, 3}
PdfManipulation2.AddImageToPage(..., Pages)
Calling AddImageToPage() with the the optional Pages parameter will add the image to all pages though.
View 14 Replies
Nov 11, 2009
I have aspx form with several textboxes.They are populated with values from a table via retrieval of a dataview.If the row count for the dataview is 0, then I'd like to reset the values in all textboxes. How can I loop through all the textboxes and set a default value?I've tried the following, but no sucess.
For Each ctrl As Control In Page.Form.Controls
If TypeOf ctrl Is WebControls.TextBox Then
CType(ctrl, WebControls.TextBox).Text = ""
End If
Next
My first For Loop was using Page.Controls but it returned only 1 count.The textboxes are inside a tabpanel (ajax), so do I have to locate the tabpage and then find all it's controls (for each tabpage)?
View 1 Replies
Mar 22, 2012
I want to pass an optional parameter to a function of type System.Drawing.Color. The problem I am having is that when I declare the function it says "Constant expression is required" but I have tried variations of the following, including integers, full qualified indentifiers, even old vbWhite constants to no avail.
[Code]...
View 14 Replies
May 28, 2010
Is it possible to set a project default for VB.NET winforms projects so that the default Modifier for controls added to winforms is Private (not Friend)?I know there's a "modifiers" property in the properties window so I can set it for each individual control however I would like to change the project so from now on myself and other developers have to specifically decide to change from friend to private. (Which I would strongly discourage them from doing).I believe there is no way of doing this, but on another forum a while ago someone mentioned it would be possible with an add-in (but didn't name the add-in or where to get it).
View 1 Replies
Dec 9, 2010
its just like that in other langauges (php in the example)
function myFunction($message,$sender="nodoby") {
return $message." by ".$sender;
}
View 2 Replies
Mar 30, 2011
im using data bound item with my combobox and this error pop up.
Parameter @UserType has no default value.
when i set the value,it stated that
"The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship. Change the data in the field or fields that contain duplicate data, remove the index, or redefine the index to permit duplicate entries and try again."
should i edit my usertype column in my database or there have another solution?
View 6 Replies
May 6, 2008
I am working on a very simple application in Visual Basic 2008 Express.
The program has a Listview where I display the "DisplayName" field, the user clicks on a name and this should fill 3 text boxes. The code is:
strSQL = "SELECT FName, LName, DisplayName FROM tStaff WHERE DisplayName=@DisplayName;"
Dim conn As New OleDbConnection(strConnString)
[Code]....
This produces the error "Parameter @DisplayName" has no defaul value"
The value of the variable "strDisplayName" is correctly captured.
View 7 Replies
Apr 12, 2011
I want to include an optional parameter in a function statement that is of the type Unit. For example:
Public Shared Function NewTable(Optional ByVal TableWidth As Unit) As Table
Optional parameters require a default value, but I cannot figure out how to set a default value for a Unit type.
View 7 Replies
Mar 9, 2012
We have a legacy component that has been converted from VB6 to VB.Net.The VB component was called from an ASPX page using Request("param") to pass optional parameters to function calls. That means the value is null/nothing if the parameter is not present.The parameters were then added to an ADODB call of a store procedure using Parameters.Append.When used from VB6 missing, Request("param") values were coerced into empty strings when passed to the VB6 component. This meant that the ADODB call was satisfied (for required parameters).When the code was ported to VB.Net, the null Request("param") values are now passed as null values (VB nothing?) and Parameters.Append skips adding the value if it is nothing. This caused the stored procedure calls to break as a required param was missing.
If we change the component's function parameters to be optional and have paramname as string = "" defaults, will a null/nothing value be converted to an empty string, or is null/nothing treated differently to a parameter being simply missing?
View 2 Replies
