特征对象

AIDL objects can be sent either as a concrete AIDL type or as the type-erased IBinder interface:

birthday_service/aidl/com/example/birthdayservice/IBirthdayInfoProvider.aidl:

1. package com.example.birthdayservice;

3. interface IBirthdayInfoProvider {
4. String name();
5. int years();
6. }

birthday_service/aidl/com/example/birthdayservice/IBirthdayService.aidl:

1. import com.example.birthdayservice.IBirthdayInfoProvider;

3. interface IBirthdayService {
4. /** The same thing, but using a binder object. */
5. String wishWithProvider(IBirthdayInfoProvider provider);

7. /** The same thing, but using `IBinder`. */
8. String wishWithErasedProvider(IBinder provider);
9. }

birthday_service/src/client.rs:

1. /// Rust struct implementing the `IBirthdayInfoProvider` interface.
2. struct InfoProvider {
3. name: String,
4. age: u8,
5. }

7. impl binder::Interface for InfoProvider {}

9. impl IBirthdayInfoProvider for InfoProvider {
10. fn name(&self) -> binder::Result<String> {
11. Ok(self.name.clone())
12. }

14. fn years(&self) -> binder::Result<i32> {
15. Ok(self.age as i32)
16. }
17. }

19. fn main() {
20. binder::ProcessState::start_thread_pool();
21. let service = connect().expect("Failed to connect to BirthdayService");

23. // Create a binder object for the `IBirthdayInfoProvider` interface.
24. let provider = BnBirthdayInfoProvider::new_binder(
25. InfoProvider { name: name.clone(), age: years as u8 },
26. BinderFeatures::default(),
27. );

29. // Send the binder object to the service.
30. service.wishWithProvider(&provider)?;

32. // Perform the same operation but passing the provider as an `SpIBinder`.
33. service.wishWithErasedProvider(&provider.as_binder())?;
34. }

• Note the usage of BnBirthdayInfoProvider. This serves the same purpose as BnBirthdayService that we saw previously.