Enum question

Hi,

I am having problems passing a correct argument that was using enum.
Hopefully someone can she some light.


// C++ enum from header file for the driver
typedef enum{
Port_A,
Port_B,
Port_C,
Port_D,
} G_PORTS;

//driver method signature
INT8 GetPortState(PORTHANDLE phandle, G_PORTS port, UINT32 signal)


//C# translation of the enum
public enum G_PORTS
{
Port_A,
Port_B,
Port_C,
Port_D
}

//C# P/Invoke
[DllImport("mylib.dll")]
public static extern UInt16 GetPortState(IntPtr phandle, G_PORTS port,
UINT32 signal);

//first implementation of the method call in application
SignalRead = GetPortState(phandle, G_PORTS.Port_D, 0x10000000);

After making the method call...I was not getting what I expected and I
stepped through the code to the driver. I found out that that
arguments that I passed as G_PORTS.Port_D was passed to the driver as
G_PORTS.Port_A. Could someone explain why is so? Thanks.

-- mario

Why is your return UInt16 when the driver returns an INT8. Based on the
name, I would think an INT8 was 8-bits.

Also, what is sizeof(G_PORTS)? Probably 32, but It would be important to
know.


"Mario" <alphatommy@hotmail.com> wrote in message
news:1157747890.734878.68570@i42g2000cwa.googlegroups.com...
> Hi,
>
> I am having problems passing a correct argument that was using enum.
> Hopefully someone can she some light.
>
>
> // C++ enum from header file for the driver
> typedef enum{
> Port_A,
> Port_B,
> Port_C,
> Port_D,
> } G_PORTS;
>
> //driver method signature
> INT8 GetPortState(PORTHANDLE phandle, G_PORTS port, UINT32 signal)
>
>
> //C# translation of the enum
> public enum G_PORTS
> {
> Port_A,
> Port_B,
> Port_C,
> Port_D
> }
>
> //C# P/Invoke
> [DllImport("mylib.dll")]
> public static extern UInt16 GetPortState(IntPtr phandle, G_PORTS port,
> UINT32 signal);
>
> //first implementation of the method call in application
> SignalRead = GetPortState(phandle, G_PORTS.Port_D, 0x10000000);
>
> After making the method call...I was not getting what I expected and I
> stepped through the code to the driver. I found out that that
> arguments that I passed as G_PORTS.Port_D was passed to the driver as
> G_PORTS.Port_A. Could someone explain why is so? Thanks.
>
> -- mario
>

Hi,

You are probably right in that INT8 is an 8-bits integer, and that I
err in that it should have been INT16. That is the closest thing that
C# has to an 8-bit integer or could byte be used in this case? As far
as the size, I get 0x04 when I run sizeof(G_PORTS) so that is 32-bits.
I am still baffled why the driver has the input of Port A regardless of
what arguments I used when calling the method. Again, thanks for your
input.

-- mario



<ctacke/> wrote:
> Why is your return UInt16 when the driver returns an INT8. Based on the
> name, I would think an INT8 was 8-bits.
>
> Also, what is sizeof(G_PORTS)? Probably 32, but It would be important to
> know.
>
>
> "Mario" <alphatommy@hotmail.com> wrote in message
> news:1157747890.734878.68570@i42g2000cwa.googlegroups.com...
> > Hi,
> >
> > I am having problems passing a correct argument that was using enum.
> > Hopefully someone can she some light.
> >
> >
> > // C++ enum from header file for the driver
> > typedef enum{
> > Port_A,
> > Port_B,
> > Port_C,
> > Port_D,
> > } G_PORTS;
> >
> > //driver method signature
> > INT8 GetPortState(PORTHANDLE phandle, G_PORTS port, UINT32 signal)
> >
> >
> > //C# translation of the enum
> > public enum G_PORTS
> > {
> > Port_A,
> > Port_B,
> > Port_C,
> > Port_D
> > }
> >
> > //C# P/Invoke
> > [DllImport("mylib.dll")]
> > public static extern UInt16 GetPortState(IntPtr phandle, G_PORTS port,
> > UINT32 signal);
> >
> > //first implementation of the method call in application
> > SignalRead = GetPortState(phandle, G_PORTS.Port_D, 0x10000000);
> >
> > After making the method call...I was not getting what I expected and I
> > stepped through the code to the driver. I found out that that
> > arguments that I passed as G_PORTS.Port_D was passed to the driver as
> > G_PORTS.Port_A. Could someone explain why is so? Thanks.
> >
> > -- mario
> >