Apparently the ToolBar itself needs to be visible before any of it's buttons' Visible properties work. I need an entire toolbar to start out hidden, then become visible after an AJAX postback (via an UpdatePanel). While doing this, I also need to control the visibility of individual buttons on the toolbar.
For now, the workaround is to set Style="display:none;" on the toolbar and set it's Visible to true. I can then control the individual buttons' visibility using the Visible property on the server. When I want the toolbar itself to become visible, on the server I say toolbar.Style["display"] = "";
This seems unnecessarily awkward and buggy. Is this intended behavior? The Visible property on toolbar buttons should always work, regardless of the visibility of the toolbar itself.