Hi

I'm new to visual c++, but OK with several other languages, however I am having build errors using an external dll in vs2010.

The external dll call is made from a button on a form. The header and lib files are as supplied with the dll, which just controls a digital i/o port. The lib file is referenced in the linker.

my simple code :-

#include <libad.h>
...
adh = ad_open("usb-pio")

Errors on build :-

1>usbpiowf.obj : error LNK2028: unresolved token (0A00000F) "extern "C" int __clrcall ad_open(char const *)" (?ad_open@@$$J0YMHPBD@Z) referenced in function "private: void __clrcall usbpiowf::Form1::button1_Click(class System::Object ^,class System::EventArgs ^)" (?button1_Click@Form1@usbpiowf@@$$FA$AAMXP$AAVObject@System@@P$AAVEventArgs@4@@Z)
1>usbpiowf.obj : error LNK2019: unresolved external symbol "extern "C" int __clrcall ad_open(char const *)" (?ad_open@@$$J0YMHPBD@Z) referenced in function "private: void __clrcall usbpiowf::Form1::button1_Click(class System::Object ^,class System::EventArgs ^)" (?button1_Click@Form1@usbpiowf@@$$FA$AAMXP$AAVObject@System@@P$AAVEventArgs@4@@Z)
1>E:\Microsoft Visual Studio 10.0\My_winform_C_Projects\usbpiowf\Debug\usbpiowf.exe : fatal error LNK1120: 2 unresolved externals

Any help much appreciated.

Best Regards

picclock