rdlc report datasource not found in mvc4

http://www.codeproject.com/Articles/473844/Using-Custom-Data-Source-to-create-RDLC-Reports

i follow this sample to develop my report in mvc4 environment, while config in report wizard,  datasource don shows any item for me to select.

so i create (asp.net web forms application) project to test the rdlc report wizard again, i success to getcpReportCustomData.Data in datasource.

i already checked the steps are correct, just don know why cpReportCustomData.Data disappear in datasource (mvc4)