What methods can be used to transmit data between two UIAbility components?

The following methods are provided, with the most recommended ones listed first:

Method 1: Call startAbility to start another UIAbility, with the startup parameters passed through wantInfo. You can also use startAbilityForResult to obtain the information returned when the called UIAbility is closed.
Method 2: Use application-level state management AppStorage, PersistentStorage, and Environment to share state data of an application or multiple pages.
Method 3: Use AppStorage or LocalStorage to pass data between UIAbility components in the same application.
Method 4: Use Emitter and Worker for inter-thread communication.
Method 5: Use the Common Event Service (CES) for inter-process communication.
Other methods: Use Call for UIAbility interaction.

Reference

Starting UIAbility in the Same Application