How To Access A DLL Function Having A Void Pointer Argument
Jan 4, 2012
I need to access a DLL function which has a void pointer argument (probably written in C/C++). In VB6 it could be accessed by declaring the argument as 'Any'. VB2008/VB2010 does not know this variable type 'Any'.
I tried instead: Object, IntPtr, UIntPtr, Int32(), Long e.t.c. but there always occurs a compile error or a runtime error.I did a lot of Internet investigation but could not find any answer.
Is there a solution to this?
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Mar 23, 2012
I want my vb.net dll to get the data sent from c++ project(exe).Can any body help on in what form this void pointer can be sent via pipe. The void pointer corresponds to enums or structures. I have to get this structures/enums on the vb.net dll end. I have mentioned about using pipe. My question is as what type the pointed to data can be send over the pipe so that I can easily handle the received data at the vb.net dll end.
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Mar 12, 2012
i need to call this c++ function
HCTRegisterReceiver( &ReceiverInfo, &m_rid )
ReceiverInfo is structure
m_rid is DWORD
this is the stucture in and m_rid variable declaration in vb.net
Public Const WM_USER As Long = &H400
Public Const WM_HCTNOTIFY As Long = WM_USER + 9[code]....
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Jun 23, 2011
I want to pass the address of a sub as a callback to another method. From what I can find, a function is passed using the format:
Public Sub test(ByRef callback as Func(ArgClass, ReturnClass))
The thing is, as mentioned, I don't want to pass it a function but a sub. There doesn't seem to be an equivalent class Sub which will stand in place of Func, and it won't allow me to set the return class as nothing, so I'm somewhat stumped. How should this problem be solved?
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Jan 20, 2011
I really need little help with unmanaged dll access from VB.NET, have been working on it about a week. I have a C++ .h files with headers. I have to access one function from the dll using VB.NET:
int
acsGetEventPoll (int acsHandle,
void FAR*eventBuf,
unsigned short FAR*eventBufSize);
Documentation says that eventBuf is a buffer where structure of type CSTAEvent_t is put after the function call. Type is defined as:
[Code]...
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Nov 5, 2011
Public Class Form1 Public Declare Function GetModuleHandle Lib "kernel32" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As IntPtr Public Declare Function GetProcAddress Lib "kernel32" Alias "GetProcAddress" (ByVal hModule As IntPtr, ByVal lpProcName As String) As IntPtr
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim hmod As IntPtr = GetModuleHandle(Nothing) 'Work Dim addrs As IntPtr = GetProcAddress(hmod , "TestFunction") 'Not work, always NULL why??
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Jun 11, 2011
i being ordered to change my function skill to returning value by using struct but not using pointer. may i know what is the pro and con between this 2?
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Mar 3, 2011
I am using visual basic and trying to create function. I am getting this error:
"Argument not specified for parameter '_IsDayRateCheckBox' of private function CalculateParikingCharges(_HoursDecimal As Decimal, _IsDayRateCheckBox As System.Windows.Forms.CheckBox) As Decimal'.
This is the code.
Private Function CalculateParkingCharges(ByVal _HoursDecimal As Decimal, ByVal _IsDayRateCheckBox As CheckBox) As Decimal
This is how I call the function.
Dim HoursDecimal As Decimal
Dim AmountOwedDecimal As Decimal
If Not Decimal.TryParse(HoursTextBox.Text, HoursDecimal) OrElse HoursDecimal < 0D Then
ErrorLabel.Visible = True
HoursTextBox.Focus()
[Code] .....
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Feb 19, 2011
I have to create a program that finds the total cost for pizza, fries, and soft drinks, and places that in a list box. So far, though, I'm stuck. I have this code so far:
Public
Class frmBill
Private
Sub btnTotal_Click(ByVal
sender As System.Object,
[Code] .....
The errors that I am getting are:
"Argument not specified for parameter 'D' of Public Function totalBill(P As Double, F As Double, D As Double)
"Argument not specified for parameter 'F' of Public Function totalBill(P As Double, F As Double, D As Double)
"Argument not specified for parameter 'P' of Public Function totalBill(P As Double, F As Double, D As Double)"
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Jul 23, 2010
I try to convert names and values parameters of function into a hashtable. For name of parameter, it's ok, but not for value.
Function test(ByVal param1 As String, ByVal param2 As String) As Hashtable
Dim hash As Hashtable = New Hashtable
Dim stFrame As New StackFrame
[Code]....
There is a property to get default value of parameter (if optional) with param.DefaultValue but how to get current value ?
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Nov 26, 2009
ok basically i've got a delegate ByVal function_to_execute As dele0 but instead of invoking it, i wish to add it to an eventhandler
Public Sub test(ByVal function_to_execute As d0)
Dim t As Timer = New Timer()
AddHandler t.Tick, AddressOf function_to_execute.address
[code].....
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Mar 22, 2011
How can I create a function that returns an object of a certain type, which the user of the function specify in the argument (using vb.net 2010) ?
[Code]...
The code above doesn't work, but maybe it can explain what I want to achieve. Using this feature, I want to hydrate my data transfer objects from datatable. Client will just call this function, specifying which DTO the client wants, and this function will just create that DTO and populating the properties with reflection GetType.GetProperties().
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Nov 11, 2010
I have several parameters consisting of separate System.Byte() arrays. What I need is the syntax for a function declaration where the parameter is an array of arrays - I do not want to delve into System.Collections, and it's my preference not to CType each array into an Object and then back into a Byte().
Problem I'm having here is that:
Public Function MyFunc(arrayparam() As System.Byte) As System.Byte()
accepts a single-dimensional Array of individual Bytes.
Then Public Function MyFunc(arrayparam() As System.Byte()) As System.Byte()
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Apr 26, 2011
How can i pass the button click as an argument in a function.
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Apr 20, 2011
Im trying to pass a array as a argument to a Javascript function from code behind(vb.net)
Code im trying
[code].....
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Sep 7, 2010
I want to specify an List(Of String) as an Optional function argument. But i am unable to initialize it in the function declaration.
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Mar 23, 2010
VB.NET is not letting me dance with both feet, or piss with both hands. I've got one foot and one arm tied behind my back at every turn. I want to use this statement in a function:
Return CType(Formatter.Deserialize(FS), DS)
Seems doable, right?
Function ReadFileStream(ByRef FS As FileStream, ByRef DS As Object)
Dim Formatter As New BinaryFormatter
FS.Position = 0
Return CType(Formatter.Deserialize(FS), DS)
End Function
Right? I mean, CType only accepts a class name as the second argument. I can't give it an instance of a class, or it croaks. Yet if I try to pass the class name as the argument to that function:
DataInfo = ReadFileStream(FileStream1, DataStruct)
VB.NET croaks on this, too, complaining that "'DataStruct' is a type and cannot be used as an expression.". It's used as an expression by CType just fine outside of the function. Does the VB.NET legislature provide a clause that allows for a 'Type' to be passed as an argument in a function? Writing all the supporting code ten million times to deserialize a file using CType ten million times in a large application will get very complicated and tricky very quickly. It should be handled by a routine so that any cases and adjustments that come up can be dealt with in one spot.
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Aug 31, 2009
I have an Excel VBA function that takes a number of optional parameters, including an optional Range:
Function DazBeta(A As Range, Z As Range, _
B As Integer, _
Optional Freq As Integer = 1, _
Optional c As Double = 0, _
Optional r As Range, _
Optional Pct As Boolean = True, _
Optional Label As Integer = 1)
I am translating to VB.NET, and it's the optional Range that is giving me grief because VB.NET does allow optional Ranges. Or rather, optional parameters must provide a default value. What is the recommended way to change the VB.NET function signature so that the code is callable from an Excel cell as a UDF? (The VB.NET implements a UDF, the assembly is registered as a COM server, and the Excel spreadsheet is told of this server and type library, allowing the VB.NET code to be called from an Excel spreadsheet cell.) I have other compilation problems, so I have not been able to explore this. I am thinking that accepting an optional Object (default value Nothing) might work and then I could cast the Object to a Range. Alternatively, if there were a default value that could be specified with an optional Range, that would work, too.
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Jul 15, 2010
I have an open source project I converted to vb.net. I solved all the errors, except for one. This is the C# line
[Code]....
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Dec 5, 2011
I made this procedure re-use a select query:
[code..]
And I use it like this if I would want the selected value placed in a textbox and it works fine
[code...]
However if I want the value to be passed in a string like so:
[code...]
The string ends up having an empty string value. How do I assign the value I queried to that String?
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Dec 29, 2010
How can I declare pointer to pointer in ATL. Actually I have a handle which I want to pass by address to function. As shown below
STDMETHODIMP Function(HANDLE* hHC) //HANDLE declared as void * so actual type is void **
OR
STDMETHODIMP Function(LONG **hHC)
And want to access this function from the VB client.
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Sep 25, 2010
I don't understand the error, Argument not specified for parameter 'test' of 'Public Shared Function TestThis(test As String)'.
Partial Public Class Form1
Shared Sub ReceiveCallback(ByVal ar As IAsyncResult)
Form1.Invoke(TestThis, New Object(){"test"}) 'error
[code].....
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Sep 20, 2011
Is there any equivalent for Typdef and Void in VB.NET.What I'm trying to do is, I have a function call for DLL in VC++ which is as follows:
[code]...
how it can be translated in Vb.NET?
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Mar 30, 2012
Im 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--
[Code]...
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Feb 23, 2011
I want when i right click to void(black space) of listview the contextmenu will show.
How i do that ? I only did with click to item oF listview.
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Oct 5, 2011
I am facing following problem with adodb Recordset
Error: Missing method 'instance void [WindowsApplication1] ADODB.Fields::Append(string,valuetype ADODB.DataTypeEnum,int32,valuetype ADODB.FieldAttributeEnum,object)' from class 'ADODB.InternalFields'
I am using 6.0 version of ADODB.
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Oct 23, 2009
What does this mean? This just started I never had this error.
at System.Windows.Forms.ToolStripMenuItem.OnClick(EventArgs e)
at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
[code]....
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Jun 25, 2012
I looked at the Dispose() method in System.Data.SqlClient.SqlTransaction (using a decompiler):
[Code]....
Why does everyone say in forums that it is Rolling back in the dispose? Where does it rollback?
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Mar 20, 2009
I'm following along with an excellent Scott Guthrie article (MVC form posting scenarios) and trying to convert it to VB along the way. I've got everything working except one piece. At one point in the article he's adding his own business rules to a LINQ to SQL entity like this:
public partial class Product
{
partial void OnValidate(ChangeAction action)
[code].....
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Apr 8, 2012
Possible Duplicate: Convert Null to zero in access databaseI'm using Microsoft Visual Web Developer 2010 Express to create ASP/VB.NET page to connect with a Microsoft office Access 07. Here's my issue:
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