  Electron transport in thin metallic wires and films is strongly influenced by
the quality of their surface. Weak localization and magnetoconductivity are
also sensitive to the electron scattering at the edges of the sample. We study
weak localization effects in a two-dimensional electron gas patterned in the
form of a narrow quasi-one-dimensional channel in transverse magnetic field.
The most general boundary conditions interpolating between the limits of mirror
and diffuse edge scattering are assumed. We calculate magnetoconductivity for
an arbitrary width of the sample including the cases of diffusive and ballistic
lateral transport as well as the crossover between them. We find that in a
broad range of parameters, the electron mobility is limited by the boundary
roughness while the magnetotransport is only weakly influenced by the quality
of the edges. In addition, we calculate magnetoconductivity for a metallic
cylinder in the transverse field and a quasi-two-dimensional metallic film in
the parallel field.
