Restore Focus after TextBox Automatic Postbacks
| Postbacks triggered by a DropDownList or a Check Box are hardly noticeable. However it’s a different story when an UpdatePanel refreshes its content after a partial automatic postback. Specifically, two side-effects will occur. |
However, if new data is required, there is an alternative solution in PageMethods, which is used by Iron Speed Designer’s popup text and image. PageMethods sends to and receives from the server much less data than partial postbacks. They apply the results to existing DOM objects instead of destroying and recreating them, thus preserving the focus and data.