Hi Yang. Personality deals with the image that you project, how other people perceive you and how you deal with other people. Character refers to the morals that a person has and their penchant to do the right thing. Someone can have an excellent character and always be depended on to do good things, but have an introverted personality . Also the nicest person in the world can be disloyal to their friends.

character意为“天性，性情，性格，个性；品格”，侧重人格、品质，特指道义方面的邪、正、强、弱等，也可笼统表示性格全貌。还有“特点，人物”等多种意义。She is a woman of strong character. 她是个性格坚强的女人。 personality意为“人格，个性，为人”，是在私下和社交场合体现的能影响他人对自己的印象或看法的性情、举止等。

Well because they are the same in the case you referred to.

Hi Yang, here is the dictionary definition of "trait" A genetically determined characteristic or condition. Traits may be physical, such as hair or eye color , or they may be behavioral such as mental illness. Traits typically result from the combined action of several genes, though some traits are expressed by a single gene.