Issue with IDataErrorInfo with text box in Expander

I have one expander and which contain text开发者_运维问答 box, text is validating through IDataErrorInfo, it is working fine when i enter wrong information, it popup with red rectangle.

but issue arises when i tried to collase the expander, and red rectangle is still there. it stayed on Expander

so please provide soem good solution....

Another solution is to create a control template where you wrap the contentpresenter element in an adorner decorator. This prevents the validation escaping the closed expander.