Hi , check here.
Obviously for simplicity your domain model -> Employee needs to inherit
IDataErrorInfo
then implement in this domain model property (which is a declared in this interface):
public string this[string columnName]
and internally check your fields there , in case of inproper data for each property notify about it in format of string data.
Also you can check here:
idataerrorinfo-for-validation-in-mvvm-with-silverlight-and-wpf/[
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