Managed C++/CLI
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This message board is for managed and mixed-mode C++ programming only: Managed C++ in VC++.NET or C++/CLI. Please post all standard C++ programming questions in the Visual C++ board[^].
cheers,
Chris Maunder
CodeProject.com : C++ MVP
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I have project which I am compiling with /clr. I have a class like below..
ref class A
{
public:
void CheckValue(void * test);
typedef ref struct val
{
std::string *x;
}val_t;
};
in my implementation I ahve to use something like below..
void A::CheckValue(void *test)
{
a::val_t^ allVal = (a::val_t^)test;
}
in my main I have used like..
int main()
{
A^ obj = gcnew A();
a::val_t valObj = new std::string("Test");
obj->CheckValue((void*)valObj);
}
I am getting type cast error and two places - obj->CheckValue((void*)valObj); and at obj->CheckValue((void*)valObj); error C2440: 'type cast' : cannot convert from 'void*' to 'A::val_t ^'
This snippet is just to show behavior at my end and I ahve to use it this way only. Earlier I was running it using non /clr so it compiled fine.
Now question I have how can I make this type casting work in C++/CLI type project?
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Getting Access Violation Exception when trying to convert unmanaged array of structures into managed in Vb.Net(VS2010,4.0 framework) in Windows 7 -64 bit mode.
Sample Source Code
_
Public Class vb_menu_dotnet
Public level As Short
Public menu_id As String
Public short_desc As String
Public parent_id As String
Public access As Short
Public flag As Short
Public menu_desc As String
End Class
Dim current As IntPtr
Dim outArray As IntPtr
Dim manArray(100) As vb_menu_dotnet
vb_dotnet_get_menu_hierarchy(p_menu_handle, p_apl_id, outArray) //C API call
current = outArray
Dim j As Integer
For j = 1 To 100
manArray(j) = New vb_menu_dotnet()
Marshal.PtrToStructure(current, manArray(j)) //Access Violation Exception
Vijay
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You may need to try a VB.NET forum. This is for C++/CLI code.
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Dim current As IntPtr
Dim outArray As IntPtr
Dim manArray(100) As vb_menu_dotnet
vb_dotnet_get_menu_hierarchy(p_menu_handle, p_apl_id, outArray) //C API call
You have not initialised any of the pointers that you are sending to the C-language library. Take a look at this P/Invoke tutorial[^] for more information.
Use the best guess
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Hi ,
whatever database u r acessing or data retrieval policy u might be using for e.g INI file,must be in Read Mode,Try to make it Write protected
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Did you actually read the OP's question?
Use the best guess
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Hi ,
whatever database u r acessing or data retrieval policy u might be using for e.g INI file,must be in Read Mode,Try to make it Write protected
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