There is a native function:
int sqlite3_config(int, ...);
I would like to PInvoke to this function. Currently, I have this declaration:
[DllImport("sqlite3", EntryPoint = "sqlite3_config")] public static extern Result Config (ConfigOption option);
(Result and ConfigOption are enums of the form enum Result : int { ... }.)
I am actually only interested in the single parameter version of this function and don't need the other args. Is this correct?
I am also curious as to how you would declare the two argument form (perhaps it would take 2 IntPtrs?).
You need to use the __arglist keyword (which is undocumented), Bart# had a nice blog about it.
Example
class Program { [DllImport("user32.dll")] static extern int wsprintf([Out] StringBuilder lpOut, string lpFmt, __arglist); static void Main(String[] args) { var sb = new StringBuilder(); wsprintf(sb, "%s %s %s", __arglist("1", "2", "3")); Console.Write(sb.ToString()); } }
The is no standard way of pinvoking vararg methods, most solutions will wrap it in several methods e.g.
[DllImport("MyDll", CallingConvention=CallingConvention.Cdecl)] static extern var MyVarArgMethods1(String fmt, String arg1); [DllImport("MyDll", CallingConvention=CallingConvention.Cdecl)] static extern var MyVarArgMethods2(String fmt, String arg1, String arg2);
