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

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How to using custom footer temple while binding field?It say studentId undefined,but studentIdis my table property
My codes like 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>");