Questions tagged [pin-ptr]
17 questions
3
votes
1 answer
Access violation when using pin_ptr?
When I use pin_ptr to pass an array in native c code, I get access violation. The code is as bellow:
array^ LogLikelihoodScore(array^>^ modelsBuffer , array^ featuresArray, int numberOfFrames)
{
int i, j,…
Hossein Zeinali
- 33
- 4
2
votes
1 answer
Is it necessary to release pin_ptr or is it done automatically?
I read the microsoft documentation about pin_ptr and it is not clear to me if it is release automatically or not. Can anyone shed some light?
Lion King
- 495
- 5
- 14
2
votes
1 answer
C++/CLI pin_ptr's usage in proper way
I am newbie of C++/CLI.
I already know that the pin_ptr's functionality is making GC not to learn to specified object.
now let me show you msdn's example.
https://msdn.microsoft.com/en-us//library/1dz8byfh.aspx
// pin_ptr_1.cpp
// compile with:…
nolleh
- 107
- 2
- 10
2
votes
1 answer
C++/CLI method calls native method to modify int - need pin_ptr?
I have a C++/CLI method, ManagedMethod, with one output argument that will be modified by a native method as such:
// file: test.cpp
#pragma unmanaged
void NativeMethod(int& n)
{
n = 123;
}
#pragma managed
void…
Whitney Kew
- 215
- 3
- 13
2
votes
1 answer
Do I need a pin_ptr to pass a literal string?
From a managed c++ function I want to invoke an unmanaged function that expects a 'const char *' as an argument.
Are a) and b) below correct? For b), do I need to pin_ptr 'hello'? What about a)? Thanks.
a)
myFunction( "hello" );
b)
char hello[10]…
Martín
- 45
- 2
2
votes
0 answers
cli::array as member in mixed class
I want to have a managed buffer as a member in mixed class:
class A {
cli::array m_managedBuffer;
}
This results in:
error C3265: cannot declare a managed 'm_managedBuffer' in an unmanaged 'A'
So I tried using auto_gcroot:
class A {
…
solyd
- 782
- 2
- 8
- 18
1
vote
1 answer
pin_ptr a native void* help
The Setup
I have a PDF API which has a native function that is defined below.
typdef void* PDF_DOCUMENT;
unsigned long PDF_GetMetaText(PDF_DOCUMENT document,
const char tag,
void* buffer,…
Tom Fobear
- 6,729
- 7
- 42
- 74
1
vote
2 answers
Using the memory allocated by a CLI array as storage for an unmanaged class
I have an unmanaged class that accepts a pointer to memory as its storage space.
e.g.
class MemBlock
{
void* mpMemoryBlock;
// Various other variables that manipulate the memory block goes here.
public:
MemBlock( void* pMemoryBlock ) :
…
Goz
- 61,365
- 24
- 124
- 204
1
vote
2 answers
How can I save a object, so that it won't get collected by the GC in C++/CX
This is the code that I have for the constructor:
LmiVideoCapturer* LmiVideoCapturerConstruct_(LmiVideoCapturer* x, const void* implementation)
{
std::vector &deviceList =…
rosu alin
- 5,674
- 11
- 69
- 150
1
vote
1 answer
how to put a pin_ptr into a generic list?
I've got a managed C++ method that takes as a parameter a list of String^
the method needs to populate an unmanaged structure with pointers to the memory in the String^
extracting the WCHAR* is simple enough with PtrToStringChars
however I dont know…
stuck
- 2,264
- 2
- 28
- 62
1
vote
1 answer
pin_ptr & PtrToStringChars vs. StringToHGlobalAnsi: Why does PtrToStringChars var loose its value?
I am using C++/CLI and I want to call the function WNetAddConnection2 from Windows Networking.
First, I know that C++/CLI is not the language of choice for my work, but I have no possibility to change that right now and e.g. use C# instead.
The…
Tobias Knauss
- 3,361
- 1
- 21
- 45
0
votes
2 answers
pin_ptr and interior_ptr in vc++
I am working on a project that was written(a HID inteface for STM32) by a person who worked before in visual c++ 2008. So to imitate the line that is causing problem, I created a sample winform application in VC++ 2008. Here is the click event with…
Vikyboss
- 940
- 2
- 11
- 23
0
votes
1 answer
Managed to native value class conversion: is it safe to cast pointer?
I have a C# project which uses C++ classes from a library. C# classes are actually wrappers for C++ classes, they expose C++ functionality to C# client code.
In many places C++ value classes are converted to C# wrappers and backwards.
During code…
whats_wrong_here
- 9
- 1
- 1
- 4
0
votes
0 answers
Convert C++/CLI User Defined Object (%) to Native C++ object (&)
How can I convert a user defined object passed by (%) to a native object (&). For example
void managed_func(user_defined_managed_obj% m_obj_)
{
// i need this
obj_ptr->unmanaged_func(&m_obj_);
}
Thus, in the above example I would like to…
AnonymousJ
- 7
- 4
0
votes
2 answers
pin_ptr performance relative to native (VC) heap objects
In a C# to native lib CLI/C++ wrapper, I have a choice:
Store native pointer in a managed class (native object is created using native "new")
or
Store native object as a data blob in a managed class' field, and use pin_ptr to pin it before each…
Yuri Astrakhan
- 8,808
- 6
- 63
- 97