The constraint clause has been specified for the type parameter "Chart". All constraints of the type parameter must be specified in a single WHERE clause

 Public Abstract classFillworkbook<tmodel, chart>whereTModel:struct    whereChart:New()    wherechart:createexcelbase{ Public voidFilldatatoworkbook (Workbook Workbook) {List<TModel> Sheetdata =GetData (); if(Sheetdata = =NULL) {Sheetdata=NewList<tmodel>(); } DataTable DT=asconvert.listtodatatable (Sheetdata); Createexcelbase Chart=NewChart (); Chart. Filldata=DT; Chart.    Createcharts (workbook); }     Public AbstractList<tmodel>GetData ();}

Execute the above code compile error:

Error 3 the CONSTRAINT clause has been specified for the type parameter "Chart". All constraints of the type parameter must be specified in a single where clause. D:\SourceProject\OLAP\trunk\EntOlap\EntOlap.Report\EntOlap.Report.Service\KefuDuizhangBiao\FillWorkBook.cs 15 11 EntOlap.Report.Service

The method declaration for the class is changed to the following:

 Public Abstract class Fillworkbook<tmodel, chart>    wherestruct    where chart:createexcelbase, New

The constraint clause has been specified for the type parameter "Chart". All constraints of the type parameter must be specified in a single WHERE clause