Calling function with pointer from a C like dll into a C# program.

[Calin]

I'm trying to build a wrapper but the pointer gives me a hard time.

the C code:

typedef enum
{
MANYMOUSE_EVENT_ABSMOTION = 0,
MANYMOUSE_EVENT_RELMOTION,
MANYMOUSE_EVENT_BUTTON,
MANYMOUSE_EVENT_SCROLL,
MANYMOUSE_EVENT_DISCONNECT,
MANYMOUSE_EVENT_MAX
} ManyMouseEventType;

__declspec(dllexport) typedef struct
{
ManyMouseEventType type;
unsigned int device;
unsigned int item;
int value;
int minval;
int maxval;
} ManyMouseEvent;

__declspec(dllexport) int ManyMouse_PollEvent(ManyMouseEvent *event);

C# code:

[DllImport("ManyMouseDLL.dll")]
public static extern int ManyMouse_PollEvent( );

 

[Calin]

I think I've figured it to a certain degree but I still don't know how
to 'fix' the enumeration.

[DllImport("ManyMouseDLL.dll",CharSet = CharSet.Ansi)]
internal static extern int
ManyMouse_PollEvent([MarshalAs(UnmanagedType.LPStruct)] ManyMouseEvent
MouseEvent);

[StructLayout (LayoutKind.Sequential)]
internal struct ManyMouseEvent
{

public int device;
public int item;
public int value;
public int minval;
public int maxval;
};


Any help is appreciated

 

[Mattias Sjögren]

I think I've figured it to a certain degree but I still don't know how

to 'fix' the enumeration.

What you have is almost valid C# code. Just strip off the typedef
stuff.

enum ManyMouseEventType
{
MANYMOUSE_EVENT_ABSMOTION = 0,
MANYMOUSE_EVENT_RELMOTION,
MANYMOUSE_EVENT_BUTTON,
MANYMOUSE_EVENT_SCROLL,
MANYMOUSE_EVENT_DISCONNECT,
MANYMOUSE_EVENT_MAX
}

[DllImport("ManyMouseDLL.dll",CharSet = CharSet.Ansi)]
internal static extern int
ManyMouse_PollEvent([MarshalAs(UnmanagedType.LPStruct)] ManyMouseEvent
MouseEvent);

Make that

internal static extern int ManyMouse_PollEvent(ref ManyMouseEvent
MouseEvent);


Mattias

 

[Calin]

I think I've figured it to a certain degree but I still don't know how
to 'fix' the enumeration.

What you have is almost valid C# code. Just strip off the typedef
stuff.

enum ManyMouseEventType
{
MANYMOUSE_EVENT_ABSMOTION = 0,
MANYMOUSE_EVENT_RELMOTION,
MANYMOUSE_EVENT_BUTTON,
MANYMOUSE_EVENT_SCROLL,
MANYMOUSE_EVENT_DISCONNECT,
MANYMOUSE_EVENT_MAX

}

[DllImport("ManyMouseDLL.dll",CharSet = CharSet.Ansi)]
internal static extern int
ManyMouse_PollEvent([MarshalAs(UnmanagedType.LPStruct)] ManyMouseEvent
MouseEvent);

Make that

internal static extern int ManyMouse_PollEvent(ref ManyMouseEvent
MouseEvent);

Mattias

Thanks that works fine.