kendo ui - How to using custom footer temple while binding field?It say Id undefined,but id is my table property -

how use custom footer template while binding field? says

studentid undefined

but studentid table property.

my code's this:

columns.bound(p => p.studentid); columns.bound(p => p.point) .clientgroupfootertemplate("<div>average: #=kendo.tostring(getpointby(studentid),'n0')  #</div><div>max: #= max #</div><div>min: #= min #</div>");