SearchForm getValuesAsCriteria missing DateItem's value

[petercaogx]

SmartGWT 5.0p

when i using DynamicForm's method getValuesAsCriteria to get form's value, it misses all DateItem's Value, and when I used getValues method to get all values of the form it has DateItem's value and it is String data type. Is it a bug?

Can someone help this?