The drill-down feature helps in temporarily hiding a part of your report. That hidden part can be controls, groups, columns or rows. When you open a drill-down report, part of the data is hidden so that you can only see high-level data until you request for more detail. In such reports you find an expand icon (plus-sign image) next to the toggle item in the report. Clicking the toggle image, or plus sign, expands hidden content into view and the expand icon changes to a collapse icon (minus-sign). When you click the minus-sign image, it hides the content and returns the report to its previous state.

To create a drill-down report, use the Visibility properties of controls, groups, columns, or rows. Simply set the Visibility-hidden property to True and set the toggle item to the name of another item in the report, usually a text box in the group containing the hidden item. At run time, this puts a plus sign next to the toggle item which the user can click to display the hidden data.

If you export a drill-down report or render it through rendering extensions, any content which is hidden at the time of export remains hidden in the exported file. If you want all of the content to appear in the exported file, you must first expand all hidden data.

Only when you render a report using the XML using the XmlRenderingExtension, all hidden data is exported regardless of whether it is hidden at the time of export.