Visual Studio 2017을 사용하는 것이 좋습니다.

Report.EnableNativeCustomReportItem 메서드

Configures the rendering object model to make custom report items available.

네임스페이스:  Microsoft.ReportingServices.ReportRendering
어셈블리:  Microsoft.ReportingServices.ProcessingCore(Microsoft.ReportingServices.ProcessingCore.dll)

public void EnableNativeCustomReportItem()

If not called for a particular type of custom report item, the AltReportItem property will appear in place of any CustomReportItem of that type. Omitting the custom report item type parameter (or providing null) will enable all types of custom report items.