C# Feature - Partial properties

Partial properties

Partial properties allow a property declaration and its implementation to live in different parts of the same partial type.

Introduced In

This feature was introduced in C# 13.0 (2024).

Why This Feature Exists

This feature is mainly useful in source-generation and code-generation scenarios, where one file declares the shape of a type and another file supplies the implementation. It reduces boilerplate in generated partial types while keeping declarations and implementations aligned.

When To Use It

Use it in generated-code scenarios where declarations and implementations are intentionally separated.
Use it in large partial types where generated and handwritten code must coexist cleanly.
Avoid it in ordinary application code unless the split is genuinely helpful.

Before

public partial class CustomerViewModel
{
  private string _name = "";

  public string Name
  {
    get => _name;
    set => _name = value;
  }
}

After

public partial class CustomerViewModel
{
  public partial string Name { get; set; }
}

public partial class CustomerViewModel
{
  private string _name = "";

  public partial string Name
  {
    get => _name;
    set => _name = value;
  }
}

Practical Use Case

One common scenario is a generated partial type that declares bindable or tracked members, while a handwritten partial file defines validation or storage rules.

Common Pitfalls

This is not a general readability improvement for most codebases.
Keep declaration and implementation naming perfectly synchronized.
Use it sparingly; partial members are easiest to justify in tooling or generated-code workflows.

Version Notes

C# 13 added partial properties as part of broader partial member enhancements.