Thursday, June 11, 2009

GetDeviceVersion() in RAPI fix

I have got a desktop application that determines the operating system's version of the device (I have used a Windows Mobile 5.0 device) connected to PC via ActiveSync. When calling the method GetDeviceVersion() exposed in the RAPI class in the OpenNETCF.Desktop.Communication library, the application crashes with the following exceptions:

When running the solution in Debug configuration:
System.NullReferenceException was unhandled
Message="Object reference not set to an instance of an object."


When running the solution in Release configuration:
System.AccessViolationException was unhandled
Message="Attempted to read or write protected memory. This is often an indication that other memory is corrupt."


When running the exe application:
Unhandled exception at 0x00000000 in XXXApplicationNameXXX.exe: 0xC0000005: Access violation reading location 0x00000000.

The solution to any of these issues is to PInvoke the method CeGetVersionEx() rather than the one provided in the RAPI class.

//PInvoke Declarations

[StructLayout(LayoutKind.Sequential,

    CharSet = CharSet.Unicode)]

public struct CEOSVERSIONINFO

{

    internal int dwOSVersionInfoSize;

    public int dwMajorVersion;

    public int dwMinorVersion;

    public int dwBuildNumber;

    public PlatformType dwPlatformId;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]

    public string szCSDVersion;

}

 

[DllImport("rapi.dll",

    CharSet = CharSet.Unicode,

    SetLastError = true)]

internal static extern int

    CeGetVersionEx(ref CEOSVERSIONINFO lpVersionInformation);



//PInvoke Call

CEOSVERSIONINFO osVersionInfo = new CEOSVERSIONINFO();

CeGetVersionEx(ref osVersionInfo);



Source: opennetcf

2 comments:

Derek White said...

Hi Ashvin,

Blog looks good.

Did you resolve the cursor display problem on the Symbol 4090?

ashvin said...

Hi Derek,

thanks for the comment...

Years back, we were told that Symbol 4090 doesn't support the wait cursor and it is not touch screen as well. Since then, nothing was done around this issue.

Did you come across any solution?

Ashvin