Data binding methods such as Eval(), XPath(), and Bind() can only be used for a databound control
Error Description:
This error occurs when you use the Eval(), XPath(), and Bind() methods to bind a DevExpress control to a data source if this control is inside a container (another DevExpress control). For example, if the ASPxGridView contains the ASPxComboBox which you try to bind to a data source.
Solution:
Do the following to solve this issue:
Disable a container control’s ViewState.
Call the container’s DataBind method in the page/container’s Init event handler.
For the ASPxComboBox: Use the DataBindItems() method instead of the DataBind method. For other editors, you do not need the DataBind method at all as the ASPxGridView binds the editors automatically.
For the ASPxGridView as a container: Disable its caching mechanism (EnableRowsCache). It is recommended to bind the grid to a data source in the Page_Init event handler if you bind the grid at runtime.