[Help-glpk] solves for mixed-integer quadratic problems

[usa usa]

Hi,

I need to solve mixed-integer quadratic problems.

(1) the objective function is linear and constraints are quadratic

or
(2) the objective function is quadratic and constraints are linear,.

(3) the decision variables are binary integers.

I have searched some open sourced solvers but I cannot find the source code.

I also need to call it from C# in VS 2013.

Could anyone recommand some open-source solvers ?

Any help would be appreciated.

Thanks