  Nonleptonic decays of charmed mesons into two pseudoscalar mesons or one
pseudoscalar meson and one vector meson are studied on the basis of a
generalized factorization method considering the resonance effects in the pole
model for the annihilation contributions. Large strong phases between different
topological diagrams are considered in this work, simply taking the phase in
the coefficients $a_i$. We find that the annihilation-type contributions
calculated in the pole model are large in both of the $PP$ and $PV$ modes,
which make our numerical results agree with the experimental data better than
those previous calculations.
