# PlatformExtensionAttribute class

Namespace: [Eto](https://eto.picoe.ca/api/namespace/eto.md) · Assembly: [Eto](https://eto.picoe.ca/api/assembly/eto.md)

```cs
[AttributeUsage(AttributeTargets.Assembly, Inherited = false, AllowMultiple = true)]
public abstract class PlatformExtensionAttribute : Attribute
```

Base extension attribute to wire up 3rd party controls and native handler implementations.

**Remarks:** All extensions are loaded via [Platform.LoadAssembly(Assembly)](https://eto.picoe.ca/api/type/eto.platform/loadassembly.md). Use the [PlatformExtensionAttribute.PlatformID](https://eto.picoe.ca/api/type/eto.platformextensionattribute/platformid.md) property to specify which platform the extension applies to.

**Derived types:** [ExportHandlerAttribute](https://eto.picoe.ca/api/type/eto.exporthandlerattribute.md), [ExportInitializerAttribute](https://eto.picoe.ca/api/type/eto.exportinitializerattribute.md)

## Properties

- [PlatformID](https://eto.picoe.ca/api/type/eto.platformextensionattribute/platformid.md): Gets or sets the platform identifier this extension should be loaded on, or null to load for all platforms.

## Methods

- [Register](https://eto.picoe.ca/api/type/eto.platformextensionattribute/register.md): Registers the extension with the specified platform
- [Supports](https://eto.picoe.ca/api/type/eto.platformextensionattribute/supports.md): Gets a value indicating that this extension supports the specified platform.