.net - Overloading Operators In C++, Exporting And Importing Then In .NET?
Jan 26, 2010
I have a weird situation. I have a C++ code that overloads the +,-,* operators and exports them in a .DLL file. Now, I want to import those overloaded operators from within VB.NET code. So it should be like this:
<DllImport("StructDLL.dll")> Public Shared Function
Operator +(ByVal a1 As A, ByVal a2 As A) As A
End Function
So what I'm trying to do above it just import the lovely overloaded operator + from the DLL.Note that the operator is already overloaded from inside the DLL, so should I import it as a Function or as an Operator like this?
<DllImport("StructDLL.dll")> Public Shared
Operator +(ByVal a1 As A, ByVal a2 As A) As A
End Operator
The overloaded plus operator is supposed to add structs. So the DLL is programmed to work on structs (C++) and I want to import it in VB.NET to work on Structures.
I have a class that implements an interface. Other objects will get an instance via a method like:
Dim AU1 as IAUC = GetAU(<some GUID>) Dim AU2 as IAUC = GetAU(<some other GUID>)
What I would like to be able to do is this:If AU1 = AU2..The parts of the class that make up the interface could be equal when the rest of the class is not, and the equality of the interface objects (if you can call them that) is complicated. Several fields have to be compared in odd ways.One option I have is to just add an Equality method to the interface, which would work, but I would rather overload the = and <> operators. As far as I can see, you cannot overload operators as part of an interface, but I was hoping that I had overlooked something.
This is in vb 2005, and I would like to be able to click a button (i.e. export to excel, import from excel) and do this.If you need any more information then just let me know.
1)How do you export the data that is displayed in a datagrid to Excel.
2)How do you import data from an excel file, and fill the datagrid with that information.
I need to be able Import and Export data from my database in the app im developing. I have been having trouble finding the proper way to do this. I have to assume some of the people using this wont have Office installed so this process as to be able to work on its own. Im using Visual Basic Express with SQL server 2008. Using LINQ to SQL with a local database. I would like it to be a simple process for the users.
I'm brand new to this forum. i have a question. i wrote some software a while back and now have a few new features I need to implement. this software currently makes use of "application settings" to store all of it's settings. Which works just fine.
I have a client that has about 40 users. He wants to be able to share his settings (that he set up in his copy of the software) with all of users. Preferably by distributing a copy of a config file that they would be able to import into there software.
I've seen a lot of posts over time relating to importing and exporting CSV. Most of the answers involve using TextReader.readline and String.split, which will not work with any but the simplest data. When you are writing for users who have the expectation that your application will work with anything they export from Excel, you will have to cover all the CSV bases.
I hope that this post will give you a clear idea of what you're involving yourself in when you decide you need to read a CSV file. The characteristics of CSV data are:The comma character is used to separate the fields. (This is obvious, but I thought I'd start with a couple of obvious points to warm up) The last field on the line is ended by the end-of-line character or the physical end of the file.Any field that contains commas, double-quotes or control characters will be surrounded by double-quote marks. Any double-quote marks within the field will be "escaped" with an extra double-quote character. For instance, the value Paul "Chuck" Norris would be converted to "Paul ""Chuck"" Norris".After the opening double-quote ANY character is valid. Including line breaks. This is why you can't use readline.I have a parser class that works nicely and I'll post that on this thread in a little while, along with some notes on using it.
I want to export data from a DataGridView to a CSV/text file. I then also want to be able to load that same CSV/text file and populate that same DataGridView at a later point in time. My information is loaded into columns in the DataGridView. That is, I am not using rows to represent records, I am using columns. As such, I need to load all the data in each column and export this, by column to the CSV/Text file. Likewise, when I load the control from the CSV/text file, I need to load each column with this information.How do you export/import from/to a DataGridView controlHow do you organize the data in the CSV/File
I recently installed visual studio 2010 and am using visual basic.The problem I am having is that some operators do not show up within the editor. For example the code line below test = 3 + 5 - 6 / 7 * 4
only displays
test 3 5 - 6 / 7 * 4
the = + operators are not visible although they are there since the program will work as intended....and if I open up the .vb file in notepad everything is there. It just won't display within Visual Studio.
I have a module with code that refers to controls on form1 form1.textbox1.text 'after adding the sub new overload below to my form my module gives me "reference to a non shared member requires an object reference" why is that? [code]
passing a variable to another formI have a module with code that refers to controls on form1form1.textbox1.text 'after adding the sub new overload below to my form my module gives me "reference to a non shared member requires an object reference"
I have a base class with the the following enum and property:
[Code]...
First off, how do I do this - is it by simply overloading it? And secondly will my original property pick up the new enum automatically when using the derived class or will I need to overload that too?
maybe it's not a method exactly. here's what I'd like to do:
Private _Columns As ArrayList Public Property Columns() As ArrayList Get[code]....
which would allow me to conveniently set the property by assigning to it various kinds of collection types... except, I can't do it because apparently the Set method has to take an argument of the type of the property itself... I get the complaint:
'Set' parameter must have the same type as the containing property
I need type parameter overloading as such:[code..]
so that i can New Map(Of Human) and the compiler will automatically match it to Public Class Map(Of TKey, TValue) and if i new Map(Of String) the compiler will automatically match it to Public Class Map(Of TKey As IEquatable(Of TKey), TValue) (since String is an IEquatable(Of String))
Right now my solution is to give the class different names as such:[code...]
I'm working together with someone on a project, but I'm writing code in VB.Net, and hes coding in VC++. I'm trying to get some kind of compatability going on, so I'm putting my support classes into a VB dll. I've tested it a little, and it seems that all of the functions work, but the operator overloading that I did in VB doesnt seem to carry over to C++.
I'm trying to overload several functions. These are first defined in an interface:
Code: Namespace Scripting Public Interface IGlobalFunctions Overloads Function InOutBox(ByVal messageBoxText As String) As DialogResult Overloads Function InOutBox(ByVal messageBoxText As String, ByVal caption As String) As DialogResult [Code] .....
It complies and runs.. But I can only use the first version of InOutBox when I try to use the next one I get an error telling me: "Wrong number of arguments or invalid property assignment".
i recently discovered a nice feature called overloading, now the question is can i also do that for outputs? for example i want to call a function that would automatically return the datatype i assign the function toright now im geting an error saying "blabla and blabla cant overload eachother because they only differ by return types
I have a problem with the VB.NET compiler failing to compile a class (in a separate C# assembly) which contains two overloads of a method with generic arguments. The equivalent code in C# compiles against the same assembly with no errors. Here are the two method signatures:
protected void SetValue<T>(T newValue, ref T oldValue) protected void SetValue<T>(T? newValue, ref T? oldValue) where T : struct
Here is the code to three assemblies that demonstrate the problem. The first is the C# assembly with a Base class that implements the generic methods. The second is a C# class derived from Base and calls both overloads of SetValue correctly. The third is a VB class also derived from Base, but fails to compile with the following error message:
[Code]...
Am I doing something wrong in the VB code, or are C# & VB different when it comes to generic overload resolution? If I make the method arguments in Base non-generic then everything compiles correctly, but then I have to implement SetValue for every type that I wish to support.
This is a general question about Object Orientation and specifically overloading functions in .NET (or any other framework or language). I am looking at an application that has a lot of duplicate code. For example, have a look at the following functions: [code] I would of thought that best pratice would be to put: //code that is specifically relevant to Test1 variable in a separate function as it is common in both functions.
For good reasons I would like to have something like truckA = truckB + truckC where only the loads of the trucks are added, not the license plate numbers. Also I don't really want to return a new object (lots of overhead), just change one or two of the properties. Only thing I can come up with is truckA.Load = truckB.Load + truckC.Load, or at best truckA.Load = truckB + truckC which still doesn't look elegant, and - worse - still requires the creation of a new Load object.(this is just a way of stating my problem; the real objects are quite big and complicated) Currently I have a Sub isSumOf so the code reads TruckA.isSumOf(truckB, TruckC)
Can someone on the VB language team explain why a function result type is not part of the parameter signature?If it were then function overloads would also work for functions that only differ by the result type. In some cases, this is useful (aka cleaner code) especially when you have strongly typed data.
Other languages have this and implement it by considering the function result as an OUT parameter either as param 0 or at the end of the param list (stack) so existing type matching verification can be performed by the compiler.
In VB, the workaround is just messy and would be easily fixed by a language change. This example is overly simplified and not meant as a solid justification for the request Say you have a parse requiirement that takes a comma delimited string in the form: "31,32,33,34" or "bob,carol,ted,alice" In you code,
I have recently come across some code that has the following. First there is a Interface with the following function Function Validate() As Boolean. That interface is then implemented in the an 'ABSTRACT' class like this. Public MustOverride Overloads Function Validate() As Boolean Implements IBusinessEntity.Validate
Question 1: Why use Overloads in the Abstract class implementation.
Question 2: The Abstract class is then inherited into a class (TestClass). In TestClass the Validate function is implemented as follows Public Overloads Overrides Function Validate() As Boolean. I understand the Overrides keyword is to insure that this is the version of the Validate that you want called and not the Abstract class version but why again use the keyword Overloads?
From what I understand you can overload a constructor of a class by simply changing the constructor signature. Also, you overload Methods and Properties of a class by using the Keyword Overloads. But why do it when your implementing an Interface method, or an Abstract Class method that's inherited.
I want to place the arithmetic operators in an array so I can randomly select one at a time. I am not sure how to declare and initialize them so that I can use them in an equation.
Did anyone else read this article under Visual Basic News? I thought it was a very bad treatment of the subject. I especially don't like articles like that when the code they post relies on Option Strict Off.
As a learning experience I decided to try and implement the Shunting Yard Algorithm(string calculator) using OOP. It was successful for as far as I took it, but it had one flaw. In order to get the stack to be accessible from the operators I had to declare it as shared, which meant that all versions of the calculator shared one stack. This very short piece of code illustrates what I came up with and the "flaw". [code] How can I maintain the functionality of anOP.add1 without declaring "something" as shared?
