🎯 What is Nullable reference type?
Nullable reference type explicitly specifies whether a variable must contain a value or may not.
Key Features
- Design-time analysis
- Explicit API contracts
- Search for potential locations with NullReference
📑 Software requirements
- .NET Standard 2.1+
- Unity 2021+
📃 How to turn on static analysis
To analyze the individual assemblies
Create a
csc.rsp file next to the
asmdef:
Add the
nullable argument to the contents of
csc.rsp:
`
-nullable:enable
`
To analyze individual .cs files
Add the
#nullable annotation context to the
.cs content:
`
#nullable enable
`
💻 Migration Guide
#### What to do with Unity UI bindings and DI Inject attributes?
Explicitly tell the analyzer that you guarantee their assignment and suppress the warnings using the
! null-forgiving operator.
#### Unity UI example:
`csharp
[SerializeField] private Image _image = null!;
`
#### VContainer DI example:
`csharp
namespace Sandbox.Domain
{
private MoveController _moveController = null!;
[Inject]
public void Init(MoveController moveController)
{
_moveController = moveController;
}
}
`
To exclude a separate part of the code from analysis, you can use the following annotation:
`csharp
#nullable disable
using System;
namespace Sandbox.Server.Responses
{
[Serializable]
public class UserResponse
{
public int Id;
public string Name;
}
}
`
🎁 Helpful Links
Nullable reference types in Unity
Microsoft guide
