Скачать или смотреть Solving Inheritance Issues in Unity C# : Accessing Base Class Variables from Child Classes

Learn how to effectively manage `inheritance` in Unity C# , specifically in accessing and modifying variables from a base class within a derived class.
---
This video is based on the question https://stackoverflow.com/q/68124617/ asked by the user 'Egor' ( https://stackoverflow.com/u/16311465/ ) and on the answer https://stackoverflow.com/a/68129034/ provided by the user 'Egor' ( https://stackoverflow.com/u/16311465/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: When I'm trying to set a value for a base class from a child class (inheritance) it does not work (Unity C# )

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding Inheritance Problems in Unity C#

When working with Unity and C# , inheritance can sometimes lead to unexpected behavior, especially when it comes to accessing or modifying variables in base classes from child classes. This problem often arises when developers attempt to set values in child classes and expect those values to carry over consistently when accessed in other classes. In this guide, we will explore a scenario where this issue arises and discuss a clear solution to ensure your classes behave as expected.

The Scenario

Let's say you are developing an enemy AI for a game. You have a base class named EnemyMove1 that defines an enum representing different enemy states, such as IDLE and CHASE. You then have a derived class, MarkusEnemy, which inherits from EnemyMove1. The challenge arises when you try to set the enemy's state to CHASE from another class (EnemyCreator1), but the state remains as IDLE when accessed later. Here's how this looks in code:

[[See Video to Reveal this Text or Code Snippet]]

The Problem Explained

Why the Value Doesn’t Change

In the code provided, you are instantiating a new enemy from EnemyCreator1 and attempting to set mainState to CHASE. However, when the Update() method of MarkusEnemy runs, it appears to access the mainState of a different instance of EnemyMove1, causing confusion. This happens due to how Unity handles components and object instances in the scene. Each time you instantiate enemyPrefab, a new instance is created, but the reference to the parent class's variable needs to be correctly managed.

Solution: Use Methods to Set State

After examining the issue further, a more manageable approach would be to encapsulate your state changes in methods. This ensures that you are properly manipulating the intended object's state. You can modify EnemyMove1 to include a method to set the state, which ensures consistent access and modifications:

Step-by-Step Solution

Modify the Base Class (EnemyMove1):

Add a method to set the state.

[[See Video to Reveal this Text or Code Snippet]]

Update the Creator Class:

Call the new method instead of directly accessing the variable.

[[See Video to Reveal this Text or Code Snippet]]

Accessing from the Child Class:

The MarkusEnemy class can access the set state correctly.

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By implementing methods to manipulate the state of your base class, you can alleviate the confusion associated with direct variable access. This approach not only simplifies the code but also enhances maintainability and clarity in your game development projects. If you're building complex systems in Unity, remember to encapsulate behaviors and state changes, as this often leads to fewer headaches down the line.

If you continue to have issues or confusion regarding inheritance in Unity C# , don't hesitate to seek further assistance!