RadAjax for ASP.NET AJAX

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Controls > RadAjax > General Troubleshooting > Most Common Mistakes

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My page went blank after I fired an event from dynamically loaded user control

This can happen of improper loading of User Controls. When loading user controls you need to have in mind two things:

  1. Always recreate the last loaded User Control on Page_Init/Page_Load
  2. Assign unique IDs to the loaded controls

If the page goes blank please check if the control is always recreated. For more info about correct loading of user controls dynamically, please refer to this topic.

 

Lost ViewState

After postback/ajax request my control does not keep its last state.

This can happen if you are loading user controls and you do not assign Unique IDs to them. In this case the framework will generate an automatic ID which can be different than the original ID and therefore the ViewState is being lost. This is the cause for losing the last state of the control.

 

Postback Events not being fired

After dynamically loading User Control I cannot fire the events of any of its controls:
This is caused by improper loading as well. If the control is persisted on the page, but its events are not fired - check if you have assigned an ID to this control. This is required by the framework to preserve the ViewState and handle the control events.

 

Loading Panel does not display (UserControl with dynamically created controls scenario)

Problem: I have a user control that is populated with dynamically created controls. After I have ajax-enabled the user control with RadAjaxPanel (RadAjaxManager) the loading panel I have specified does not display at all when any of the dynamically created controls triggers the Ajax request (though the Ajax request itself is completed successfully and the content is updated).

Solution: The most likely reason for this behavior is missing ID for the dynamically created controls. Please make sure you are assigning an ID to the controls and you should experience no further problems.