I have the following structure:
[StructLayout(LayoutKind.Auto,Pack=0)] private unsafe struct BIRDSYSTEMCONFIG { public byte bySystemStatus; public byte byError; public byte byNumDevices; public byte byNumServers; public byte byXmtrNum; public ushort wXtalSpeed; public double dMeasurementRate; public byte byChassisNum; public byte byNumChassisDevices; public byte byFirstDeviceNum; public ushort wSoftwareRev; public fixed byte byFlockStatus[127]; }
Based on C ++ structure:
typedef struct tagBIRDSYSTEMCONFIG { BYTE bySystemStatus; // current system status (see bird system status bits, above) BYTE byError; // error code flagged by server or master bird BYTE byNumDevices; // number of devices in system BYTE byNumServers; // number of servers in system BYTE byXmtrNum; // transmitter number (see transmitter number bits, above) WORD wXtalSpeed; // crystal speed in MHz double dMeasurementRate; // measurement rate in frames per second BYTE byChassisNum; // chassis number BYTE byNumChassisDevices; // number of devices within this chassis BYTE byFirstDeviceNum; // number of first device in this chassis WORD wSoftwareRev; // software revision of server application or master bird BYTE byFlockStatus[BIRD_MAX_DEVICE_NUM + 1]; // status of all devices in flock, indexed by bird number (see note in BIRDFRAME definition) - see bird flock status bits, above } BIRDSYSTEMCONFIG;
And the following function:
[DllImport(@"Bird.dll", CallingConvention = CallingConvention.Cdecl)] private static extern bool birdGetSystemConfig( int nGroupID, ref BIRDSYSTEMCONFIG psyscfg, bool bGetDriverCopy );
Based on C ++ function:
BOOL DLLEXPORT birdGetSystemConfig(int nGroupID, BIRDSYSTEMCONFIG *psyscfg, BOOL bGetDriverCopy = FALSE);
What I call so:
BIRDSYSTEMCONFIG sysconf = new BIRDSYSTEMCONFIG(); birdGetSystemConfig(1, ref sysconf, true);
But get an error message:
Cannot marshal parameter # 2 ': Invalid managed / unmanaged type combination.
What does it mean? Why is this happening? How can I overcome it? All suggestions are welcome!
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