I'm trying to pass a callback function from a C++ dll to a VB.NET application.Here is my current C++ code :
void DLL_EXPORT registerEvent( void (*callBackFunction)(string str),string str)
{
callBackFunction(str);
}
void test(string str)
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I am trying to convert a DLL function call which has the Callback function routine called within the DLL function call.The DLL function call signature is like this:
typedef void *HANDLE;
typedef HANDLE HACQDESC;
DECLARE_HANDLE (HWND);
[code]....
how to convert this DLL call to VB.NET and also how to create the callback function and send it as parameter to this function
call.
I get a compile error Type "ctltype" is not defined with this code.
This is .NET 1.1 legacy code so not good I know.[code]...
I'm trying to convert C++ API to VB.Net, but this function is too hard and i don't know how make it work.
Here is the API doc for this function:
void RemoteDllSetReceiver(void *inst, on_received_buffer_t received_buf_cb);
Sets a callback function to receive notifications from the DLL. The prototype of the callback is:
typedef bool (*on_received_buffer_t)(void* inst, const unsigned char *buffer, unsigned int size);
Where inst is the pointer originally passed to RemoteDllSetReceiver buffer & size contain the notification text as defined in the Remote Protocol. Note: notifications may arrive in different threads (e.g. network, timer, audio).
I can't imagine what i mus do with on_received_buffer_t, must it be a delegate? Like you can read, this functions returns notifications from the DLL like connection status, user id...
I am exposing some ISO C++ data types to .Net (mono on Linux to be precise).For the purpose of brevity, I shall refer to C# in my question, although my question relates to all of the .Net languages (with C# and VB.Net being my target languages). So far, I have worked out how to expose the ISO C++ data types in C# class(es) for use in mono -The only problem so far is how to deal with the C++ callbacks. In .Net languages (C# and Vb.Net), I believe 'delegates' are the callback equivalent.
Sticking with C# for now, can anyone recommend a way that I can register the C# delegate functions with my ISO C++ code.The ISO C++ code is a notification library, and I want to be able to "push" the notifications to the mono framework (i.e. C# delegates in this case).My underlying assumption is that the mechanism/steps to implement this would be the same for the .Net languages - I'll just have to code the actual delegates in the .Net language of choice - is that assumption correct?Last but not the least, is the question of thread saftey. The underlying ISO C++ code that I am exposing to .Net (mono to be more specific), is both re-ntrant and thread safe - do I have to do anything "extra" to call .Net delegate from my ISO C++ code?
I was trying to use the System.Threading.Timer to run a function every 250ms - but I'm finding it difficult to cancel the timer from within the callback function. I can't seem to find a reference to "this" (js has this - it's so nice). At any rate - how could I start a callback running 250ms from now - without a timer - and then if I want to continue it again do another start for 250ms.
View 3 RepliesI want to make an numerical integration method with takes in an analytic function and integrate it over a specific interval. For the numerical integration procedure I want to use some procedures in nr.com. The problem is that these are programmed in C++ and they uses functors to pass a function to the integration method. How can I do this in VB 2010?
I want to initialize the function (i.e. set a=1,b=0 for function y(x)=a*x+b) and then pass the function to the integration method. Then when the integration method call the function it only calls the function with one parameter (i.e. x since a,b is already set)
What is the best way to do this in VB2010?I want to make a general integration method where I can pass any single valued function and integration limits.
I have just started using VB, and from what I have found so far it seems like the tools you have is
- to us a delegate for the function
- to use a lambda expression for the function
- send a pointer/adressOf
- to create a function class/structure and submit this to the function
As for now I am most inclined to create a function-class. But I am not really sure how.F.ex. I make different classes for each "uniqe function" I want to integrate, but how can I pass them to the integration function when I need to specify the argument type in the integration-function-call?This seems like a basic problem which applies to many Math operations, so I think it would be very useful to clarify this.
I want to make a GetAllContacts method which takes a sort parameter of type Func(Of Contact, TKey) which is the same type that the OrderBy method for an IEnumerable(Of Contact) takes.[code]"Too many arguments to extension method 'Public Function ElementAtOrDefault(index As Integer) As Contact' defined in 'System.Linq.Enumerable'." on the second parameter.
View 2 RepliesIm a student doing an assignment, how do i pass the value from a sub procedure to a function procedure....i want to pass the value from decSubtotal to a function procedure named CalculateDiscount; check out my code--
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I have a statement:
dat.XoaNhanVien(Me.dtgcapnhatthongtin.CurrentRow.Cells(1).Value, message)
That is a function for deleting info. Now I want to create other function and get above function to parameter. I mean:
Public Function func(Byval func as " What type can be ?")
I want to pass the entire array to the next function[code]...
View 3 RepliesI'm trying to pass 2 bitarrays to a function that ANDs the bitarrays and returns the count of bits that are set to TRUE. However, something strange happens when I reference the bitarray from within the function and the results are non-sensical.
So I have output the bitarray contents before it is passed to the functionand they match the source data, then I output the contects of the bitarray from within the functiona and they are completely different.
I'm working on a VB.NET DLL right now, and one of the functions I'm writing is supposed to take a file, and clip out an array of bytes (the method I've got works, and can be abstracted away here). What's the best way to pass a file to this function? Would passing a filename to it be best, or what would be the best way to accomplish this?
View 2 RepliesI'm trying to give a default value to the register property method. This required a function, but passed as an object(delegate?).[code]....
I want to call that registerproperty method, but I don't know how I can do that in VB.net. I just need to pass along a new Person object and I thought this was the way to go[code]....
I just want to ask if it is possible to create a function that accepts an expression into its arguments. Just like what IIF do. Ex: Dim strResponse as String = IIF(Msgbox("Select Yes or No", vbYesNo) = vbYes, "Yes", "No") I forgot the code, but its the thought that counts.
View 1 RepliesThe is a calculate function for example Function Calculate (Byval v1 as integer, Byval v2 as integer, byval op as ????????) as double return v1 op v2
End Function Anybody tried this?
I don't want to use functions for every operation (multiply,divide, etc.). I wanna pass a operator same as I pass the values. How come nobody ever had this need in VB? Using enums could work but still...
i need to pass array value to a function , here are the details
function MyTest(byval a as integer, byval b() as string)
if b is nothing
msgbox("no array")
[Code]......
I have an array of integers and I want to pass the array to a function that will add up the elements of the array and return the cumulative total of the elements of the array. So, if the array contains the values {1,2,3,4,5} the return value from the function would be 15.
View 2 RepliesThe code below is used in a Linq to SQL solution, and is in the Load event of a form. It works fine to display an ordered list of people's names, and set the value member to that person's ID. However, I'm going to be using these 'people' comboboxes a lot, so I'd like to put a sub into my Utility code there is only one line in the form's Load event.
I want to call something like: Call ComboboBoxPeople(cbo, tblTurnbackMain, ReportedByID)
The sub would begin like: Public Sub ComboboxPeople(cbo as Combobox, tbl as 'sometype', fld as 'someothertype')
What can I use as the parameter types for tbl and fld?
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if this is a dumb question. I don't ever have to write anything in VB.NET.But I am passing variables named "name" to a function and sometimes it may be 1 name or 2 names, etc. I want to check in the function if its only 1 name don't add a comma, if it's 2 names add a comma. Is there a way to get how many "names" there are?
EDIT: Added my ode to make my question a little more clear. sorry for not doing it before.
My Code:Public Function GenerateCSV(byval str as string, byval str1 as string, byval str2 as string, byval GrpName as string)
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I have Listview which databound to Dataset with about 20 items per row. I have a function which executes on each ItemTemplate appearance and gets about 10 params from Eval("something"). So basically one function builds and image from 10 parameters.Instead of passing 10 Eval("something") to the function is it possible to pass it whole row and how to use this row inside of function because it is not simple DataRow or ListView row which i can access as array of items (datacolumns).Reason i do that because function looks ugly and each time i need to change it i need to deal with dozens of items.
View 2 RepliesIm having a very difficult time trying to pass an vba array ive built from ms- access vba to a .net function.I don't have a com problem I can reference the library just fine from vba but and i can call a simple function from vba. however my problem exist when i attempt to try to pass an array to the vb.net function. vb.net code
View 3 RepliesCan we pass parameters to a function using delegates
Private Sub UpdateLabel(byval text as string)
If Me.Label1.InvokeRequired Then
Me.Label1.Invoke(New MethodInvoker(AddressOf UpdateLabel))
Else
Label1.Text = text
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I have a variable that I am trying to get to iterate up by one, i.e. X starts at 0 x+1 on first pass thererfore its at 1 then x+1 on second function call therefore x=2 and so on. I've tried the different loop and for commands but I cant get one to stay until the next function call, does it need to be a global variable? I'm sorry if this is in poor form or improperly formatted, definently trial by fire going into the object oriented world.
View 9 RepliesCan I pass a form as a parameter in a sub like public Sub GetData(Byval Frm as form) and access its controls?I have few forms (you can say: FrmAccounting, FrmEngineering, FrmIT) with almost the same controls in each of them (txtEmployeeID, txtEmployeeName, optMale, optFemale etc), where no two forms are open at same time, and each of those forms have a Button which opens a new Form (you can say FrmCollectData) now I want to fetch data in FrmCollectData depending on which form it was opened from.. like if user was on FrmEngineering and it clicks button to open FrmCollectData.. form collectData fetches data from FrmEngineering Controls and if user was on FrmAccounting and it opens FrmCollectData, form Collectdata fetches data from FrmAccounting..
earlier, in VB6.. In one of the Sub written in frmCollectData I checked which form is opened by setting flags in each of forms (frmEngineering, frmAccounting etc) and then I passed the same form in a sub which writes data in frmCollectData controls.. but am not able to do the same in VB.NET.
Okay so what im trying to do is make a simple particle system in VB (Yes i know this isnt a ideal setup). Im going to have particles dieing and spawning new ones tho, To do this i need to be able to pass a function to the particle when its created then call that function when it dies. Is there a way to do this by passing function pointers?
View 9 RepliesI have a multidimensional array (not jagged array) that saves data from rows and columns of an excel spreadsheet. After it completes recording the data from Excel, I need to pass the array to another function.I understand how to pass a jagged array, but not a true multidimensional array.
Can someone point me in the right direction? I've done some searching on this site, and others, but most of the info only includes single dimension arrays or jagged arrays.
I don't think I fully understand passing values from a sub to a module. Here is what I'm trying to do (problem is at the '****):
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I think I've seen something like this before - where the actual function returns a value. Is this possible? Or would I have to pass an integer variable from the sub to the function, and then return it back to the sub?
I would like to pass array to function as parameter. Here is an example for variable that is not array:
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Im having a very difficult time trying to pass an vba array ive built from access vba to a .net function. I dont have a com problem I can reference the library just fine from vba but and i can call a simple function from vba. however my problem exist when i attempt to try to pass an array to the vb.net function. vb.net code
<ComClass(ComClass1.ClassId, ComClass1.InterfaceId, ComClass1.EventsId)> _
Public Class ComClass1
Public otag As String()
[code].....