Скачать или смотреть How to Check if a Serializable Class Object is Null in Unity C#

Learn how to effectively check if a `Serializable` class object is null in Unity C# and discover practical workarounds.
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How to Check if a Serializable Class Object is Null in Unity C#

When working with Unity and C# , developers often encounter the need to check if an object of a Serializable class is null. This can pose a challenge, especially if you're accustomed to typical null checks with regular classes. Many Unity developers have found themselves in situations where they encounter unexpected behavior — such as always getting a false result in their null checks — due to Unity's serialization mechanism.

In this guide, we will delve into why checking for null on a Serializable object behaves differently in Unity and explore several solutions to effectively manage this challenge.

Understanding Serialization in Unity

Unity employs a unique method for managing Serializable objects. When a Serializable object is declared and later checked for null, Unity automatically instantiates a new object of that type if it detects a null reference. This auto-instantiation can lead to confusion because the null check would lead you to believe that the object is indeed null, while in reality, it has been instantiated.

Key Points to Note:

Objects that are Serializable will initialize automatically to avoid null references.

This auto-instantiation only applies to custom classes; references to Unity's built-in UnityEngine.Object are serialized as actual references.

Possible Solutions

1. Use a ScriptableObject or MonoBehaviour

One solution to check for null involvement can be leveraging Unity's ScriptableObject or MonoBehaviour. Here’s how you might go about it:

Define a ScriptableObject or MonoBehaviour Class: Create a script that derives from ScriptableObject or MonoBehaviour and use that as your intended class.

Manage Instance: You will need to manage the instance properly by keeping references either within the scene hierarchy or via assets.

Downsides:

This method does require additional asset management and may not be the most streamlined approach given certain project structures.

2. Implement Custom Serialization Logic

Another option to explore is implementing your own serialization logic using the ISerializationCallbackReceiver interface. This gives you fine control over how your object is serialized and deserialized.

3. Check for Validity by Adding Default Values

In many cases, you can assume that your object should hold some "valid" state. Here’s an example based on the ScheduledRoutine class provided:

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

By giving your properties default values and checking against them, you can effectively manage states of validity without relying on null checks explicitly:

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

Conclusion

Working with Serializable objects in Unity can be tricky due to its serialization mechanism. However, by understanding how Unity handles these objects and employing one of the solutions discussed, you can easily manage null references and ensure your code behaves as expected.

If you’ve encountered null check issues with Serializable objects in Unity before, consider trying one of these solutions. With a little adjustment, you can achieve accurate checks and write more stable Unity C# code.