把va转换为volatile u_int8_t类型的指针，并且间接访问该指针指向的地址保存的值。
Integer types:uint8_t,int8_t,uint16_t,int16_t,uint32_t,int32_t,uint64_t,int64_t Floating-point types:float,double Zero-terminatedstring Variable length binary data (blob) NVS assigns each key-value pair to one of namespaces. Namespace names follow the same rules as key names, i.e...