# ResourceUrlsCallbackAnnotation Constructors

- Package: [Aspire.Hosting](/reference/api/csharp/aspire.hosting.md)
- Type: [ResourceUrlsCallbackAnnotation](/reference/api/csharp/aspire.hosting/resourceurlscallbackannotation.md)
- Kind: `Constructors`
- Members: `2`

Represents an annotation that provides a callback to modify URLs that should be displayed for the resource.

## ResourceUrlsCallbackAnnotation(Action<ResourceUrlsCallbackContext>)

- Name: `Constructor(Action<ResourceUrlsCallbackContext>)`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/bd20f904cde09ecb9c9ae5116a6f13614bf2d7c2/src/Aspire.Hosting/ApplicationModel/ResourceUrlsCallbackAnnotation.cs)

Initializes a new instance of the [ResourceUrlsCallbackAnnotation](/reference/api/csharp/aspire.hosting/resourceurlscallbackannotation.md) class with the specified callback.

```csharp
public sealed class ResourceUrlsCallbackAnnotation
{
    public ResourceUrlsCallbackAnnotation(
        Action<ResourceUrlsCallbackContext> callback)
    {
        // ...
    }
}
```

## Parameters

- `callback` (`Action<ResourceUrlsCallbackContext>`)
  The callback to be invoked.

## ResourceUrlsCallbackAnnotation(Func<ResourceUrlsCallbackContext, Task>)

- Name: `Constructor(Func<ResourceUrlsCallbackContext, Task>)`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/bd20f904cde09ecb9c9ae5116a6f13614bf2d7c2/src/Aspire.Hosting/ApplicationModel/ResourceUrlsCallbackAnnotation.cs)

Initializes a new instance of the [ResourceUrlsCallbackContext](/reference/api/csharp/aspire.hosting/resourceurlscallbackcontext.md) class with the specified callback.

```csharp
public sealed class ResourceUrlsCallbackAnnotation
{
    public ResourceUrlsCallbackAnnotation(
        Func<ResourceUrlsCallbackContext, Task> callback)
    {
        // ...
    }
}
```

## Parameters

- `callback` (`Func<ResourceUrlsCallbackContext, Task>`)
  The callback to be invoked.