Telerik Report Viewers can display only Telerik Reports generated by our Reporting engine. They are not designed to display ready documents. Generally, when a report is requested to be displayed or refreshed in the viewer, it will be generated anew exactly for the reason that the data may have changed.
If you want to be able to display a report with older data, you need to preserve the old data, and when necessary to generate the report with this preserved old data. For example, you may implement an ObjectDataSource and use a Report Parameter value as an argument passed to the data member of the ObjectDataSource. Based on the argument value the logic of the data member should decide whether to fetch the fresh data or use old cached data, e.g. when the old-data report was created.
Another approach is an ObjectDataSource with two data members. One data member method to return the real data freshly fetched from the database. The other method may be used to provide data cached from a previous call to the database. Then you may use a dedicated Report Parameter, which value to indicate which data member to be used to extract the data for the report. For this purpose, you may use the approach described in the Change Connection String dynamically through a report parameter KB article. Instead of 'DataSource.ConnectionString' you should use (type manually) 'DataSource.DataMember' and specify the name of the method.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items