I have the following class in a .NET class library:
Code:
Public Class JasonTest
Sub New()
End Sub
[Code]....
The .AddNumbers call works fine, but the AddStrings call yields the error 'Object doesn't support this property or method'.
Is there any way to call a shared method from .NET in VB6? I was unable to find any documentation on this.
I am trying to add shared members in derived classes and use that values in base classes...
I have base
class DBLayer
public shared function GetDetail(byval UIN as integer)
dim StrSql = string.format("select * from {0} where uin = {1}", tablename, uin)
end function
end class
[Code]..
currently there is error using the tablename variable of derived class in base class but i want to use it i dun know other techniques if other solutions are better then u can post it or u can say how can i make it work? confused...
I have a form (frmMain) that contains a custom control (con class). frmMain contains a combo box control and when the user selects a value from it, I pass this value to a sub routine within con class (see red line below). This purpose of the sub routine is to populate a set of comboxes contained in con class according to the value that is passed in.
Private Sub cboGuidelines_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cboGuidelines.SelectedIndexChanged
If bChanged = True Then
[code].....
I have a function that 2 derived classes use, but the third doesn't, would it make sense to just leave it in the base class, even though one of the 3 derived classes doesn't use it?The only way I could think of disallowing the third class is to basically create an intermediate class that is derived of the base, then the 2 that use the common function are derived off the second class.
Is it possible to prevent the 3rd class from using the function, while letting the two that are supposed to use it, use it?Does that just seem to go overboard, I mean as long as I don't "try" to call the function from the 3rd class, it shouldn't be a problem, I just was interested if there was a way to prevent it all together without a lot of hassle.
I have created a Interface and a couple classes that implement this Interface. I am in the process of developing a Shared Class that utilizes the functions that each of the individual classes have, due to the interface implementation.What i need to know is how do i develop this Shared Class so that way each of the methods within it are restricted to a single data type. This single data type needs to be restricted to any class that has implemented the Interface.
Some examples:
Public Interface IVector(Of T)
Sub Add(ByVal v2 as T)
[code]....
As you can see it would allow me to develop one form, since i have standardized the required Subs/Functions for any class the implements the IVector interface. As i am still in developement, i was wondering if my current understanding of the method generics is correct in its current form or what i would have to do to make the Generic Shared Class work in the fashion that i am looking for in the example implementation.
What is the purpose of using shared methods that return an instance of a class, as opposed to a constructor?
ie: in VB.net, the system.drawing.color class has shared method "FromArgb(int, int, int) as color". This is different from java's implementation which simply is a constructor that takes three ints. Why the decision to do one or the other?
I'm wondering what will actually change a class, in the sense that serialized objects of this class will no longer be recognized. If the class has reference to shared methods of another class. Will changing such shared methods also change the classes that reference them?
View 3 RepliesI have large group of functions that I would like to store in basically a library and simply call the functions from the controls on my forms. Back in VB 6 I would have done this with a module, but now I have been told that a Public Class is the correct way in .NET. How should I go about doing this?
View 2 RepliesSo I implemented my own form of Enum static classes so I can associate strings to enumeration values. One of the shared functions in each enum class, GetValue, is used to quickly look up the string value from an internal array via the offset. While all of the enum classes implement the same exact function, the data types of their parameters differ, specific to the enums in each class.
So I come to a point where I want to create a generic class that can use any of the enums by passing it as a generic type parameter. But I cannot find a way to constrain type T in such a way to be able to call each enum's GetValue function. This is where an interface would come in handy, but VB.NET forbids interfaces for shared methods.
I have a base class that I could constrain to, but the base class doesn't implement the GetValue method, and I can't define a generic version of it, because I need to rely on shared properties of each child class in order for GetValue to do its thing.[code]..
I've created a class library and built a dll (release build). I've then referenced the DLL in another project (I've tried several). I can see the namespace and classes in Object Browser and I can declare instances of the classes but I cannot use or see any of the methods or properties! there is no IntelliSense whatsoever and calling the methods manualy results in a 'Declaration expected' error.
Within the class library solution I have a unit test project referencing the class library project which works all works fine (and all the tests pass).
Can anyone provide any pointers to what might be going wrong here? I've built plenty of dlls in the past and have had no trouble referencing them at all.[code]...
I am writing my first class-library in VB.NET. My idea is to distribute this library so others may use it in their applications.However, perhaps due to my lack of experience in writing and structuring the library and the classes therein, I noted that the methods/properties are ALL being shown in the IntelliSense of Visual Studio.
The thing is that many of them are only used within the library itself and should NOT be used by the developers (could create a disaster) when they incorporate my library in their application - only a few should be visibile i.e. the ones which are needed by the developer.Thus, my question is: is there a way to hide certain methods/properties of my library from Visual Studio's IntelliSense? Maybe something similar to REM?
EDIT: as mentioned - this is my first library and I now understand that my question could be intepreted in two ways:
1) how to hide something from IntelliSense
2) how to prevent a developer from using and calling certain methods/properties
Of course, the end-result that I want is that the developer is not able to access AT ALL certain methods/properties i.e. No. 2 above.
control which will need to be reused in several forms in my program. It basically consists of several buttons in a panel. To start with, what I need to do is get the button values from the control into a text box on the first form. But I don't want to have a method calling the textbox directly from within the control, because then it won't be reusable in my other forms. Is there something I can do in VB like parentform.textbox.append for example, where you can generically call the methods of the form in which the control appears?
View 2 RepliesI am just testing how to use dll and after googling a lot, I made it work partially...Created new project Class Library, named it myFirstDll and made a Public Shared Sub helloDll to do something. Now since this is my first time, the dll is simply showing the input in a msgbox:
Public Shared Sub helloDll(ByVal msg As String)
If msg <> "" Then
MsgBox(msg, MsgBoxStyle.OkOnly, "WE HAVE SOME MSG")
Else
MsgBox(msg, MsgBoxStyle.OkOnly, "NO MSG")
End If
End Sub
After building the dll-file, I started a new project using normal windows forms, named it "useMyDll", I clicked Project -> Add Reference, and added my dll. The program file that I made needed a textbox and a button for using the dll:
Private Sub useDllButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles useDllButton1.Click
Dim msg As String = Nothing
msg = TextBox1.Text
myFirstDll.myFirstDLL.helloDll(msg) 'this will be in msgbox in dll-file
End Sub
And when running this I could write something in the textbox and a msgbox with that input would pop up. Really happy with that. My first attempt to make a dll and use it was very successful. Then I thought, what about running the dll from rundll32.exe? It would be handy to make a dll that could be run without my exe. After googling a long time, I tried to add a new button:
Private Sub useDllButton2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles useDllButton2.Click
'Now let us see if we can open it using rundll32.exe ?
Dim msg As String = Nothing
msg = TextBox1.Text
[CODE]...
Now the first button still works just fine, but the second button gives some error (translated to english would be) like "missing entry: helloDll" I also tried to open with command prompt, same result.
After googling again I read one place that you can't run a visual basic dll with rundll32.exe, so is this true? Or is there some way of doing it? I read one place that it works if you make the dll be "COM-Visible", but I don't really understand how to or what it means. I tried to open properties, clicked Assembly Information, and "Make assembly COM-Visible", but this doesn't change anything. Then I read somewhere that it has to be in a module to work. Could it be that I need to rewrite some codes and it would work, or would I have to start learning c++ in order to accomplish this?
I have a class like this:
[Code]...
It works, when I make getBar methods public, but I don't want to expose these unneccessarily. Why I can't call private shared methods from a public one in the same class is over my head. I'm using .net framework 4.0 in a web application.
Given in the following language specification, for me at least, calling Db.Foobar() [In the following code] does not indeed call off to the Shared Constructors of the base classes. I am curious as to a) is this my own fault for doing something wrong or b) is this an error in the language specification[code]...
View 2 RepliesI am not sure how clear my question is by the title, but I am trying to make Class methods instead of Instance methods in Visual Basic that way I don't have to waste memory and code creating temporary objects to execute methods that don't need instance variables.
I am not sure if you can do that in VB but I know you can in Objective-C by using either a "+" or "-" sign in front of the method declaration. And in C++ (at least I think, I can't remember) you put the static keyword or const keyword in front of the function.How would I do this in VB if it is possible? Or should I just make a separate set of functions that are not members of a class?
As a followup to the previous question I have asked "ASP.Net Architecture Specific to Shared/Static functions" I am still struggling to understand the implications of using shared methods in ASP.NET.
So for example let us take the following code.[code...]
I am developing an application that has multiple forms and I wanted to know the best method to have application wide methods and functions. Currently I am using a Module with all my methods that are needed to be used across the entire application in it. However, I read at one point that modules should not be used, as they are only there to preserve backwards compatibility with older VB code. Is there a better way to have methods able to be called anywhere?
View 1 RepliesI Want to know which one is preferred while coding to use Static Methods or normal instances, I prefer to use static if they where few but if there was many of them I start to get some doubts
[code]...
if the EmployeeManager Has Many methods (selects deletes updates) is it ok to make them all static.and if it was Normal instance. wouldn't be a drawback if the object is initiated every time specially if GetAllEmployees() is heavily used.What is the better approach to use?
If you can't use Me. in a non-instance method, how would you use properties/functions from a base class in a Shared method?
For example, ClassB inherits from ClassA
ClassB has a Shared Method DoWork();
ClassA has a ReadOnly Property SecurityKey
How do I Public Sub DoWork() Dim test as String = Me.SecurityKey End Sub
I want to create a subclass of a class that has some shared methods. These shared methods all call one specific method. But I can't redefine that specific method in the subclass. If I try to make it overridable in the parent class, it says that shared and overridable can't both be used.
[Code]...
I seem to find more and more that I declare a lot of objects or methods as Shared now but it feels like I am not doing things properly.I try to avoid doing this but then I just end up with situations where I have to create an instance of a class just to call one method that would act no differently if it was just a shared method.Basically I'm just wanting to know if there is any good reason to avoid using Shared objects/methods. Obviously I dont declare EVERYTHING as shared, but it just seems to make things a lot simpler most of the time.For example in my current project (a chat application using WCF) I have a class just called Core which houses a lot of the main functions of the client program, so it has methods such as: SignUserIn, SignUserOut, SendMessage, MessageReceived etc and it also holds properties such as a list that contains all of the currently online users. These things are all declared Shared in my program because as far as I can see there is no reason for having to do this:[code]
View 15 RepliesI now have a need to dynamically load a dll into my application and I've found the reflection/assembly information and it's fairly easy to implement so I thought I was on my way. However, I quickly found out that I'm only able to use 'shared' methods. What I was originally thinking was I could have one shared method 'library.beginprocess' and then that would make all the necessary calls to the other methods, but this doesn't work unless all the other methods and class level objects are also shared.
I feel like I'm missing something or somethings just going right over my head. I've looked at many, many sites and examples, but I've only run across examples that expose 1 method,[URL]..which explain how to implement a plugin architechture, which I have not tried yet, but maybe would allow me to keep my class structure the same without having to make everything shared?
I want to extend the BitConverter class with an overload of ToString() that takes a parameter of type Char, representing a value delimiter.Why? By default, the ToString() call returns a string representation of a byte array, delimited by dash symbols. The signature does not allow you to specify a different delimiter, which I find very unfortunate.Now because this is not an instance type, or maybe because I'm overloading a shared method, I'm having a hard time finding the proper syntax to define my extension method.What am I doing wrong here, causing the overloads to not show up in IntelliSense:
Imports System.Runtime.CompilerServices
Module BitConverterExtensions
<Extension()>
[code].....
I have a List(Of AddlInfo) with AddlInfo being an object. I'm trying to pass addlInfoList by reference into a function of another class:
[Code]...
This works if I'm not passing the reference into another class, but when I try to do this, I get the following error: Overload resolution failed because no accessible 'Sort' can be called with these arguments:
[Code]...
I have a Visual Basic Class Library project. It generates a DLL. Is there a method to generate a static .LIB to which I can do a static link?Alternatively, can I do a static link against a DLL?
View 6 RepliesI have a tab control on first page of which there is a flexgrid. some functions are called which throughout make chages to this flexgrid. now during runtime I create more tabpages with exactly the same Flexgrid (as in I have named it the same as the first one so that I should be able to call the same functions and the same modifications should happen with this flexgrid as well. How should I call the function so that the flexgrid used is the one on my new tabpage. if I just call the function with the code Call functionname(), it modifies the same flexgrid control in the first tabpage and does nothing to the new ones on the newly created tabpages
View 14 RepliesI've been wasting so much time on this. Basically I want to have a list of objects and I want to call some specific methods of some specific bjects..g.MsgBox(Instances(0).Position(0).ToString)It should alert a number that presents the X position, but it is not working... the box does not even appear and no errors.
View 8 RepliesIt's been a while since I've had the time to browse through here, answer questions and ask some of my own. Just got a job at a custom business software developing company! But I do have a question I'd like some clearing up on.
What I have here is 2 classes, one inherits the other. Both function similar so a lot of the methods are the same for each. The one in particular is Reset_Class()
Here is a sample code of what I'm trying to do.. My question is, is it correct?
vbnet
Public Class Form1
Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As
[Code].....
In C# I'm calling a function on an interop class (Connection, written in VB6), which itself returns a plain object (System). Then there's a function on that object (InitialiseData) that I also call (even though the compiler isn't aware of it). var isInitialised = Connection.System.InitialiseData(path); The problem is, because that System object is returning a mere Object, I get the compile error "cannot resolve symbol". I can see why, but the same thing works fine in VB.NET:
[Code]...