一直不知道如何设置LookUpEdit 为可写状态.看了官网的KB(Knowlegde Base)https://www.devexpress.com/Support/Center/ViewKBIssue.aspx?kbid=A869(英文),才知道原来这么简单的!在Properties将TextEditStyle 设置为standard即可!
如图:

官方说明:
How to Use the ProcessNewValue Event of a LookUp Editor?
Article ID: A238 ; Product Group: How to Use the ProcessNewValue Event of a LookUp Editor