# OpcWriteAttributeValueCallback<T> Delegate

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx">Opc.UaFx</a></dd>
<dt>Assembly</dt>
<dd>Opc.UaFx.Advanced.dll</dd>
<dt>Package</dt>
<dd>Opc.UaFx.Advanced v2.59.0</dd>
</dl>

Represents the method that will write the value of a node attribute.

## Syntax

<div class="api-signature" data-lang="csharp">

```csharp
public delegate OpcAttributeValue<T> OpcWriteAttributeValueCallback<T>(
    OpcWriteAttributeValueContext context,
    OpcAttributeValue<T> value)
```

</div>

<div class="api-signature" data-lang="vbnet">

```vbnet
Public Delegate Function OpcWriteAttributeValueCallback(Of T)(
    context As OpcWriteAttributeValueContext,
    value As OpcAttributeValue(Of T)) As OpcAttributeValue(Of T)
```

</div>

## Type parameters

| Name | Description |
|---|---|
| `T` | The type of attribute value to write. |

## Parameters

| Name | Type | Description |
|---|---|---|
| `context` | [OpcWriteAttributeValueContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecontext/) | The [OpcWriteAttributeValueContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecontext/) to use to write the attribute value. |
| `value` | [OpcAttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/)&lt;T&gt; | The [OpcAttributeValue&lt;T&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/) to write. |

## Returns

[OpcAttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/)&lt;T&gt;

The [OpcAttributeValue&lt;T&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/) written.

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.5–v2.59 |