The names were all given by the emperor himself. To correct what I said on the first floor, the princess did have a name, but it was just not passed down. Before the Qing Dynasty entered the customs, there were more than ten princesses who left their names.
In addition, the names are always given to the children after they are born. That's why we see in historical materials that there is a record like "how many months (years) he died, unnamed" behind the earthly prince who died many years ago.
In addition, before the Qing Dynasty entered the customs, the names were relatively rough, and they were all simple Manchu. For example, "Dorgon" means "badger", Azige means "younger son" and so on.
This feature was still maintained when he first entered the customs, such as Shunzhi's eldest son "Niu Niu".
As the emperor's Han culture improved, in the late Shunzhi period, the emperor began to tend to name his children with auspicious words in Chinese, such as "Fuquan" for Prince Yu, "Changning" for Prince Gong, and "Longxi" for Prince Chun. "Of course Kangxi's name was given by Tang Ruowang, so there are some exceptions.
In the Kangxi Dynasty, the names of princes initially tended to be transitional to some profound ancient Chinese characters, such as "Baocheng" for the prince (from "it is better to protect what has been accomplished"). Of course, there are also remaining Manchu names. Legacy, such as Kangxi's fourth son who died in infancy, "Sai Yin Chahun".
Later, as Kangxi's cultural level increased, he began to standardize the names of his children. So it was determined that "Yin" was the fixed second character, and "礻" was the radical of the third character. Therefore, the eldest son Baoqing changed his name to "Yinfeng", and the prince Baocheng changed his name to "Yinreng".
Emperors since Kangxi have followed this naming rule. When Qianlong arrived, he not only named his son, but also determined the generational lineage of "Yongmian Yizai" for the next four generations of descendants. When he arrived in Daoguang, he continued the eight characters as "Pu Yu Heng Qi Tao Lu Zeng Qi", thus establishing the name hierarchy of the descendants of Aisin Gioro even today.