1. A magnetic field sensor device for determining two or three components of a magnetic field, comprising at least one Wheatstone bridge with two half-bridges, each half-bridge comprising at least two bridge resistors and at least one of the two bridge resistors being a magnetic field-sensitive resistor with regard to a magnetic field component located in an X/Y magnetic field sensor plane, a ferromagnetic flux concentration element being arranged symmetrically between the two bridge resistors which, with regard to a Z magnetic field component oriented perpendicular to the X/Y magnetic field sensor plane, generates antisymmetric magnetic field components located in the X/Y magnetic field sensor plane, wherein at least one of the circuit arrangement of the bridge resistors is individually switchable, the supply voltage of at least one half-bridge is individually switchable, and at least one of the magnetic field-sensitive bridge resistors have a switchable resistance characteristic curve so as to enable switching of at least one resistance characteristic curve, wherein in a first state an X/Y-located magnetic field component is measurable and in a second state a magnetic field component located in the Z direction is measurable.