I'm working on a code (WinForms C# NET 3.5) that involves using unrar.
[DllImport("UNRAR64.DLL")]
private static extern IntPtr RAROpenArchive(ref RAROpenArchiveData archiveData);
[DllImport("UNRAR64.DLL")]
private static extern IntPtr RAROpenArchiveEx(ref RAROpenArchiveDataEx archiveData);
[DllImport("UNRAR64.DLL")]
private static extern int RARCloseArchive(IntPtr hArcData);
[DllImport("UNRAR64.DLL")]
private static extern int RARReadHeader(IntPtr hArcData, ref RARHeaderData headerData);
[DllImport("UNRAR64.DLL")]
private static extern int RARReadHeaderEx(IntPtr hArcData, ref RARHeaderDataEx headerData);
[DllImport("UNRAR64.DLL")]
private static extern int RARProcessFile(IntPtr hArcData, int operation, [MarshalAs(UnmanagedType.LPStr)] string destPath, [MarshalAs(UnmanagedType.LPStr)] string destName);
[DllImport("UNRAR64.DLL")]
private static extern void RARSetCallback(IntPtr hArcData, UNRARCallback callback, int userData);
[DllImport("UNRAR64.DLL")]
private static extern void RARSetPassword(IntPtr hArcData, [MarshalAs(UnmanagedType.LPStr)] string password);
Since i want the code to be working on both 32BIT and 64BIT i wanted to assign UNRAR64.DLL or UNRAR.DLL via a string unrarDll depending on check for bitness of system.
private void DllChoice() {
if (SystemIs64Bit()) {
sevenZipDll = "7z-x64.dll";
unrarDll = "unrar.dll";
} else {
sevenZipDll = "7x-x32.dll";
unrarDll = "unrar64.dll";
}
}
private static bool SystemIs64Bit() {
return (IntPtr.Size == 8);
}
Error is thrown:
An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type
IS there easy way around this? What would be the proper way of doing this?