∵函数f(x)=e x(sinx-cosx),
∴f′(x)=(e x)′(sinx-cosx)+e x(sinx-cosx)′=2e xsinx,
∵x∈(2kπ,2kπ+π)(k∈Z)时,f′(x)>0,x∈(2kπ+π,2kπ+2π)(k∈Z)时,f′(x)<0,
∴x∈(2kπ,2kπ+π)(k∈Z)时f(x)递增,x∈(2kπ+π,2kπ+2π)(k∈Z)时f(x)递减,
∴当x=2kπ+π(k∈Z)时,f(x)取极大值,
其极大值为f(2kπ+π)=e 2kπ+π[sin(2kπ+π)-cos(2kπ+π)]
=e 2kπ+π×(0-(-1))
=e 2kπ+π,
又x∈(0,2013π),
∴函数f(x)的各极大值之和S=e π+e 3π+e 5π+…+e 2011π
═
e π (1 -e 2π×1006 )
1 -e 2π =
e π (1 -e 2012π )
1 -e 2π .
故选:B.