If you need a field which is "an int32 value, or not set" you can use the google.protobuf.Int32Value message type. ---- In proto file,Which field type I can use?
在 2015年7月17日星期五 UTC+8下午9:10:29，Jon Skeet写道： > > On Friday, 17 July 2015 02:34:21 UTC+1, Wu XIANG wrote: >> >> >> Is it true that has methods for optional fields in proto3 are removed >> from generated message ? >> > > For primitive types, yes. > > >> If so, how can I decide if this field has been set or not ? >> > > You can't. An int32 field that's been set to 0 is exactly the same as an > int32 field that hasn't been set at all. > > (For oneofs, you could still tell that it was the int32 field that was > set, so that's slightly difference.) > > From the documentation: > > > Note that for scalar message fields, once a message is parsed there's no > way of telling whether a field was explicitly set to the default value (for > example whether a boolean was set to false) or just not set at all: you > should bear this in mind when defining your message types. > > If you need a field which is "an int32 value, or not set" you can use the > google.protobuf.Int32Value message type. > > Jon > > -- You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/protobuf. For more options, visit https://groups.google.com/d/optout.
