In C# you can use the implicit keyword to define an implicit user-defined type conversion operator.
In VB.NET you can define a CType conversion operator that will explicitly convert a user-defined type into another type.
Is there a way to declare an implicit conversion operator in VB.NET?
I have a C# library that internal clients configure with VB.Net Their scripts are throwing an InvalidCastException where they really shouldn't.
So the code is something like this (massively simplified):
//C#3
public class Foo {
public static implicit operator Foo ( Bar input )
[Code].....
Strange - it looks like the VB.net compiler can find the cast operator but it's lost at runtime. Surely the VB and C# IL will be pretty similar here?
The VB.net code is dynamically compiled - the compile happens the first time a user logs into the app. it's being compiled as VB.Net against .Net 3.5, and I'm not using any COM interop.
I am having a structure that is actually a simple byte with more functionality.[code]...
If there would be a way to inherit from Structure I would simply inherit from Byte adding my functionality, basically I just need a byte Structure with custom functionality.
My question is also valid when you want to define your new singleton member value-types (like, you want to define a nibble-type for instance etc.) and you want to be able to set it with an assignment to number or other language typed representation.
I do the following:
Dim rw() as exportDataset.vendorPricingRow = ExportDataset.vendorPricing.Select("field1 = 1")
i have a simple code just have a look End Class
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When i add num1 and num2 as above, compiler gave error that -- Operator + is not defined for types "type" and "type".How to define the meaning of '+' or any other operator in such situations?
I have defined a Sub in vb.net, with 'Of' type parameter like this:
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I want to just add number1 and number2, But as you can see error has occured where i want to sum number1 and number2 saying that '+' is not defined for type 'VarType'. how to add these variables in Such Methods.
VB 2008 Express edition. I'm pretty new to VB2008, a little over halfway through my first classi am writing a console program to ask the user for the price of gas for 7 days, then to get the average of that price. here is my code so far:
Option Strict On
Module Module1
Sub Main()
[code].....
I have 2 methods with the same name, with diferente signatures.
Public Sub Method1(ByVal Parameter1 as String, ByVal Parameter2 as Boolean)
Public Sub Method1(ByVal Parameter1 as Integer, Optional ByVal Parameter2 as Boolean = False, Optional ByVal Parameter3 as Boolean = False)
If I call Method1("My String Parameter", False) it will not give and error, it will try to convert the parameter to integer and use the overload.
Is there a way to forbid the implicit conversion in this specific method or in this specific parameter. For instance, I changed the second method name, but its not an elegant solution.
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The code compiles and seems to run correctly, but is underlined with the message "Implicit Conversion from 'Double' to 'Single'" Why would this be an implicit conversion if each of the variables is cast as a Single? Is this something I should worry about or change?
I encountered due to a coding error a behaviour I can't explain.In one line I have an implcit conversion from a string to a boolean value:
Class myClass
Public Property myString() as Boolean
Return "123" '<= Implicit Conversion occurs here
End Property
End class
[Code]...
Are there any differences in the behaviour between the .NET Versions?The code is compiled against .NET 2.0 with implicit conversion on.
VB.Net just showing its true colors again? When I turn Option Strict On, I am still able to do implicit narrowing conversions in a for each loop.For example, this code actually compiles;
Private Sub foobar()
Dim foo() As foo = {New foo}
For Each bar As bar In foo[code].....
From my understanding of Option Strict, this should not work.See here "Restricts implicit data type conversions to only widening conversions".My code above is a narrowing conversion, and so should be illegal.It will fail at runtime with an InvalidCastException.
C# does the same thing. Below is another implicit narrowing conversion.
private void foobar()
{
foo[] foo={new foo()};[code]......
would like to define some custom Implicit conversion function within my VB class. How can i do that. I have seen samples in C# but not in VB
View 8 RepliesDim
Dr As
DataRow
Dr = DataSet11.Jobdata.NewRow
[code]....
With Option Strict On, I am getting an error with the above code, which is part of a procedure to add a new record in an 2003 access database table named "Jobdata". The items in Combobox3 is populated by another table in the same database, which has a Status field and a Key field. What I'm trying to do is to insert in the Status field in Jobdata table the correspoding integer value in Key to which ever
status is selected from the combobox.
I am a novice programmer to VB 2008 and I am trying to develop the following code for a game. When I build the following code, an error message appears:
Option Strict On disallows implicit conversion from integer to string.
Another error message
appears: Name FuchsiaTurnScoreLabel is not declared.
Option
Strict
On
Public
Class PlayForm
'Declare integer and decimal variables for calculations
[Code] .....
I am getting this warning in my code, and for the most part I have ignored it.
Friend Sub StartTablet()
Dim success As Boolean
Dim eventObject As IntPtr = IntPtr.Zero
[code]....
Option strict on disallows implicit conversion from 'Integer?' to 'Integer', 'Integer' to 'String'
Here's my code which is just a stub. I am working off of some example code and applying it to my own project:
<System.ComponentModel.DataObjectMethodAttribute _
(System.ComponentModel.DataObjectMethodType.Select, False)> _
Public Function GetTrackActivitiesByParams(ByVal ActivityKey As Nullable(Of
[Code]....
Is there a technical reason why there is no implicit conversion from DBNull to the various nullable and/or sql types? I understand why the conversions don't currently happen, but don't understand why an implicit conversion wasn't created at the time or added in subsequent versions of the framework.Just to be clear, I'm looking for technical reasons, not "because that's they way they did it" or "I like it that way".
View 2 Replies[code] I get the error message of "Option Strict disallows implicit conversion from Long to UInteger." [code] I dimensioned each variable as a UInteger and not a Long, the values for both X & Y are well below the maximum values of a UInteger as far as I can tell (Data Types Summary). [code]
View 5 RepliesI have a class that overrides Ctype operator to have conversion from and to String :
Public Class TotoToString
Property value As String
Public Sub New(ByVal V As String)
Me.value = V
End Sub
[Code] .....
I am building an equation parser, it takes the equation
"( 3456 + 321 * X ) / 45"
For example. As I couldn't find a direct solution to parse this equation, I split the equation and started implementing the operations 1 by 1 until I stuck with the execution order of the arithmetic operators (as the multiplication should be performed before the addition). So I am trying now to avoid this and try to parse the full equation. Is there a way to convert the string "+" to + for example?
I'm trying to create a linked list of an array of integers. Why is the following implicit conversion required?
When I run the code that contains that conversion, I get the following error.
As a real-time data acquisition user control data (a packet of an array of bytes) arrives every second, is converted into an integer array and inserted into a linked list.
The most recently arrived data is painted as coordinates on a grid at the right of a PictureBox using Graphics.DrawLine (pen,X1,Y1,X2,Y2).
The oldest data (arriving 120 seconds ago) will be drawn at the leftmost portion of the Picturebox.
Why a linked list rather than a list? To display 120 views of time sequence data, the draw routine the most recently inserted node to a node that points to Nothing. How do I limit the length of the linked list to 120 nodes and always ensure that the last node points to Nothing?
Do While Not item Is Nothing
item = item.NextItem
Loop
I have written a small program to aide my business and the program works fine. But while compiling the code it shows a lot of warnings like the following."late bound resolution; run time errors may occur""implicit conversion from 'Object' to 'String'." Where am i going wrong. Even though the options strict off removes the warning I want to correct the warnings.
Private Function ledgerMasterFullName(ByVal i As Integer) As String
Dim fullName As String
Dim vObj As Object
[code]....
When I try to read the file, I am getting an error = "Option strict on disallows implicit conversion from string to Char"
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I am writing a library in VB.NET in which I have added, among others, a class originally written in C# but converted into VB.NET. I don't know much about C# so therefore I have used online C# to VB.NET-converters. Now I am stuck with some code which I believe the online-converter was not able to "translate" properly.
When running the code I get the following error:
System.IndexOutOfRangeException was unhandled
Message="IndexOutOfRangeException"
StackTrace:
at System.String.get_Chars()
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Is there a way to disable the new VB 2010 implicit line continuations feature in Visual Studio 2010. We are using an TFS 2008 built service which doesn't support the new feature (sources in VS 2010 without errors getting built errors in TFS 2008 built service / we cannot update to TFS 2010 built service).
View 6 RepliesCODE:
When the program runs out to the red code, it clewed error, the error screenshot shown as Figure 1.
I want to ask the wrong place, and how to modify the program.
I know that here there is a similar question but I would like, if possible, to be able to define a relative path for 'Start External Program' or any workaround that do not constrain me to add a complete new empty project to my solution. I am using VB.NET in Visual Studio 2010 environment developing WinForms apps.
View 4 RepliesI am tightening up my coding with the Option Strict set to ON. It has now produced alot of errors. An example of this is:
If AllocatedDGV.Rows(i).Cells("RoomNumber").Value = RoomsAvailableDGV.Rows(j).Cells("RoomName").Value Then
It gives me the following error: Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity.
I need to write an interface to get data to/from our data files.
We have a low level class that holds field values for each record read from the files.
This just holds two values, the value read from the file (DBValue) and the updated value that may need to be written back to the file (CurrentValue).
These values may be any of the standard value types (integer, date etc) or a string.
Either value (DBValue or CurrentValue) may be null if not defined.
I have written the class to manage this data which works fine while option strict is NOT on.
But we have an office policy of having option strict on all the time.
When I put option strict on, my object value comparisons fail with the error: "Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity."
Question, how should I change the following code to handle option strict on ...
This is all running on Visual Studio 2010
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Possible Duplicate: Is there a conditional ternary operator in VB.NET?
Can we use Coalesce operator(??) and conditional ternary operator(:) in VB.NET as in C#?