Calling Unmanaged Dll Function With Void* Parameter?
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]...
View 1 Replies
ADVERTISEMENT
Aug 9, 2010
In VS2010 I'm encountering a PInvokeStackImbalance error when I call an unmanaged C function that takes a string argument. This only happens in VS2010 (works fine in earlier versions of vs). I know the MDA is more strict in VS2010 but I can't seem to figure out what the actual problem is.
[Code]...
View 2 Replies
Dec 14, 2009
The following two statements seem the same to me but the first throws a design time error, and the second does not. The first one is passing the first parameter in hex and the second passes the first parameter as its decimal equivalent.
Public Shared ReadOnly Test As New Guid(&HCC58E280, &H8AA1, &H11D1, &HB3, &HF1, &H0, &HAA, &H0, &H37, &H61, &HC5)
Public Shared ReadOnly Test2 As New Guid(3428377216, &H8AA1, &H11D1, &HB3, &HF1, &H0, &HAA, &H0, &H37, &H61, &HC5)
Here is the error associated with the first statement:
Error 1 Overload resolution failed because no accessible 'New' can be called with these arguments: 'Public Sub New(a As Integer, b As Short, c As Short, d As Byte, e As Byte, f As Byte, g As Byte, h As Byte, i As Byte, j As Byte, k As Byte)': Constant expression not representable in type 'Short'. 'Public Sub New(a As UInteger, b As UShort, c As UShort, d As Byte, e As Byte, f As Byte, g As Byte, h As Byte, i As Byte, j As Byte, k As Byte)': Constant expression not representable in type 'UInteger'.
View 1 Replies
May 30, 2012
I need to write a DLL in C that is used a plugin for an existing application.The DLL has to be compiled by the Visual Studio 2008 compiler with the following options.[code]It's then linked to applications library's.What it actually needs to do and what's causing me the issues is that within one of the methods it needs to pull data from a sql server 2008 r2. From what I've seen today you wouldn't be able to do this directly in C as SQL Server past 2005 is designed to communicate with CLR languages( C#, C++, VB.Net).It was suggested that I handle all the database communication with a VB.Net dll and then call said function from within the C dll. Most of what I've found on the topic of calling managed dll's from unmanaged code has talked about pinvoke or com wrappers and mainly from the perspective of c++.
View 2 Replies
Nov 2, 2011
I'm calling unmanaged C++ Dll function from VB.Net project by usin dllimport attribute like this;
<DllImport("Injection.dll", CallingConvention:=CallingConvention.Cdecl)> _
Private Shared Sub Injector(ByRef Client As String, ByRef Dll As String)
End Sub
View 4 Replies
Dec 1, 2009
I am trying to use an unmanaged dll in my VBE2008 Project. My application works fine on my computers (3 Vista sp1 and 2 XP sp3 / all with .net framwork 3.5), but after the sp2 update for 2 of Vista machines, it throws often an AccessViolationException (on those machines with Vista sp2). The error message is:"Attempt to read or write protected memory. This is often an indication that other memory is corrupt."I have checked and found that the exception was thrown by the dll call-sub.
<DllImport("RefProp.dll", EntryPoint:="SETUPdll", SetLastError:=True, CharSet:=CharSet.Ansi, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
[code].....
View 6 Replies
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?
View 11 Replies
Aug 20, 2010
We have a VB.NET program that needs to periodically call a function in an external, unmanaged DLL to communicate with our legacy application. We are having a problem with the application (seemingly) randomly not being able to find the DLL with the unmanaged code. Currently we use DECLARE FUNCTION blah LIB for the unmanaged code. Would it be better/more reliable to use DllImportAttribute instead? Or am I missing something else?
View 1 Replies
Feb 17, 2010
I have an unmanaged DLL and need to call one of its functions. Here's the [code]...
View 5 Replies
Jun 12, 2009
I'm having some trouble finding the syntax for making function calls to unmanaged DLLs in VB.NET. Let's just assume there's a function "Connected" in unmanaged DLL "Connector.DLL". I want to call this function by creating an abstract function call to it.
I've seen some code out there that looks something like
[DllImport("Connector.DLL")]
Public Shared Function Connect(ByVal intPort)
But that syntax doesn't work for me.
View 2 Replies
Mar 9, 2011
I want to have a "template" function that can receive different parameter and a type parameter, like:[code]But Vb told me that tupeList is not defined... is there a way I can do that?
View 2 Replies
Feb 17, 2011
I'm currently working with a client's VB.Net code, which was developed for them by a small development shop a few years ago and which they purchased and have been maintaining and uprgrading since. This client's primary developer is out on indefinite (likely permanent) medical leave and I'm now filling in until they bring in a full timer (as I'm a contractor here). My current task is to add some functionality to a the VB.Net code they purchased. I'm finding practices and techniques in the code that absolutely baffle me and can't make the code do what I want. I'm starting to wonder if it's me and was hoping to get some thoughts on the code I've encountered.
For example: Setting a variable to accept the result of a function by calling the function with many parameters, clearing the parameters in the function, setting them to some value, calling another function with those new values, then never using the values returned by the functions. I'll add a code snippet in the first comment since this is already getting long.
View 9 Replies
Sep 14, 2010
I have a function where I am performing a lot number of database operations inside a Sub. The operation when called directly like:ExecProcess()
takes about 11 seconds to run.However, if I create a Delegate, and call the sub using BeginInvoke(), the very same process takes over 40 seconds to execute.Here's the threaded code:
Protected del As ProcessDelegate
Protected Delegate Sub ProcessDelegate()
del = New ProcessDelegate(AddressOf SELocal.ExecJob)
Dim cb As New AsyncCallback(AddressOf Me.ExecJobComplete)
del.BeginInvoke(cb, del)
Anyone know what may cause a function to take longer inside a new thread, rather than calling directly?
View 2 Replies
Dec 13, 2011
I need to execute a stored function in oracle or sql through vb.net. I created a command object. Depending on the database type(oracle or SQL) i am preparing the Command text as Select functionName(?,?,?,?,?,?,?,?) from dual; (For Oracle) Adding the parameter values of the function. Now performing the ExecuteScalar which is not working saying invalid parameter. This works with ODBC connection string. But ODBC doesn't with 64bit. My Requirement: Code should execute a user defined stored procedure by taking the values at runtime.
View 1 Replies
Mar 30, 2012
I am having a problem with the BackOrdered Function of my program. I can`t get it to say anything but 0 when I run the program. Another problem I am having is the input box pops up like 6 times and it`s only suppose to once. [Code]
View 9 Replies
May 28, 2012
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 Replies
Mar 12, 2010
In VB.NET, it is entirely possible to pass an integer as a string parameter to a method without calling .ToString() - it's even possible to call .ToString without the ()'s. The code will run without a problem, VB will interpret the integer as a string without having been told to. In C#, these would cause compilation errors - you are required to call .ToString() and to call it correctly in that situation before it will compile. Is there a way to make the VB compilation process check for the same things as the C# compilation process? Would it be best practice in a mixed team to force this check?
View 3 Replies
Oct 3, 2011
I have used the PInvoke Signature Toolkit to create VB.NET function definitions for three fairly simple C functions contained in an external DLL. The problem is that two of the parameters are structures so pointers need to be sent and one structure (fileview) is undefined.
OpenFileView(filename, &fileview_ptr)
ReadFileInfo(fileview_ptr, &fileinfo_ptr)
The structure of fileinfo is defined so I can create a structure definition in VB.NET and create an IntPtr to that structure with Marshall.AllocHGlobal. And then I can use Marshall.StructureToPtr to copy the data and do the inverse when the data is returned.
[Code]...
View 1 Replies
Dec 7, 2009
I'm having some problems calling a C function from a DLL. The function is returning -101 which translates as a "bad parameter". The values I am passing have been returned from another, successful function call, so my current assumption is that I've built the structure incorrectly.The function definition is:
int sm_switch_channel_input(struct sm_switch_channel_parms *switchp)
Parameters
*switchp (a structure of the following type):
typedef struct sm_switch_channel_parms {
[code].....
View 2 Replies
Mar 18, 2009
in a DLL that takes a pointer to a structure as a parameter.The C and VB code is as follows.Am I passing the structure in calling the DLL correctly? I am asking because the API call returns a valid error code indicating error opening the com port specified. I tried all valid ports (com1 on a Vista 32 machine with a USB-Serial device and com1 defined in device mgr, com1 and com2 on a desktop with winxp and 2 real serial ports).I dont have the code for the DLL and cannot debug into the DLL code.
C code
typedef struct _SETUPPR {
CHAR Port[5];
[code].....
View 1 Replies
Mar 15, 2011
I'm sure this is a pretty simple question but I can't seem to find the answer on Google. Say I've got a function that does some stuff and returns a string. I can assign its return value to a variable:
Dim result As String = MyFunction()
But sometimes I want to perform the actions within the function but I don't care about the return value. I know I can simply call the function from code.
Sub Main()
' Code
MyFunction()
' More Code
End Sub
This works and does exactly what I need it to. My question is - are there any issues or pitfalls in doing this? Particularly I want to make sure I'm not introducing any performance or memory leak issues.
View 4 Replies
Apr 9, 2010
The function is something like this: "function recieveFindPlayerResponse(displayString)"Now, how can I call it. I was trying this:Call AxShockwaveFlash1.CallFunction("_root.recieveFindPlayerResponse(displayString)")And before I had this, I had a Call function which defines displayString. (Works, as I've tested it before, and no error is given to this.)Now, how can I call a function like the above?
And example of what the code looks like from ******* swf decompiler is:
function recieveFindPlayerResponse(displayString)
{
[code].....
View 4 Replies
Mar 17, 2010
in VVB.net I have a string that contains the name of a function, say dim funcstr as string = "MyFunc1". How do I call the function or sub whose name is contained in the string funcstr (in this case, MyFunc1)?
View 9 Replies
Feb 28, 2012
going to need to call unction within a FoxPro program. I believe within my VB program I will need to create a service which will need to cal
View 7 Replies
May 8, 2012
I have an aspx page populated with data from an access database using this code:
<asp:datalist id="bookData" runat="server" RepeatDirection="Horizontal" RepeatColumns="3">
<ItemTemplate>
[Code]....
I would like each entry of data to have a button associated with it that could call a server function to submit data to a database. I currently have the button implemented, but no idea how to go about calling a function that would be able to detect what button was clicked.
View 1 Replies
Jun 14, 2012
i have this question i was trying to find a way to call a javascript function from asp controllers and i did here is the code :
<script type="text/javascript">
function hello() {
alert("hello world")
[Code]....
and i want to call it from a javascript function so it will be like controller----call---> javascript ---call--->code behind
View 3 Replies
Sep 27, 2011
I've designed a Windows Service in Visual Basic 2005 that needs to call some functions from a DLL written in Delphi 5. If I try to add this DLL as a reference, I get this error:
"A reference to 'C:ProjectsServiceProMDPUpdateServiceMessageStubApplicationSPHost.dll' could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component."
I assume that it is just not possible to add this DLL as a reference to my VB2005 project, since the DLL was written in an old version of Delphi, correct? This isn't a big deal, as I can just use the DllImport function from System.Runtime.InteropServices, but if it is possible, adding it as a reference would be preferred.
My other question is, how would you be able to call a function from the DLL using DllImport, if the function you are trying to call takes a Delphi record data type as a parameter (if this is possible)? If possible, would I need to pass each field in the record separately or would I be able to define a structure in my VB app that mirrors the record definition in the Delphi DLL and pass that? Or, would it be best if I just created another function in the Delphi DLL that took various string/integer/boolean/etc. parameters that I could call from VB that would then call the original function in Delphi? I tried searching the internet for this specific question, but I couldn't find anything that looked useful.
[Code]...
View 1 Replies
Jun 2, 2010
I have an XML file with a list of tasks to be executed. One of the elements of the XML file is funcName (function name), which is the name of a function to be executed in my Visual Basic.NET application (v4).I can retrieve the string name of the function, but how do I go about running it? I have two Class files, GUI and DISP.[code]
View 2 Replies
Sep 2, 2011
Is it advisable to call a function from another form?Does it have any side effects on the system while running, like more process will consume?I have a function that will set the background in a form, it will make the image stretch, backcolor transparent and will set the picture. If I will use that function in other 15 FORMS I can minimize my code.
View 9 Replies
Sep 24, 2010
I have an 100 aspx files with one module file for code. All these aspx files have the same backend function, so i created on public module for all these files to access. These files are in the same folder. But for some reason the aspx files cannot access the function from that module.
mod1.vb Code (.vb file)
Public Module Allinone
Sub Allinone_Load(ByRef Page As Web.UI.Page)
[Code]....
I am at a roadblock of why the aspx files wont read this module? Also all these files are in the same directory
View 1 Replies
