# IOpcData<T> Interface

<span class="api-meta">since v2.25</span>

<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>
<dt>Members</dt>
<dd><a href="./members">IOpcData&lt;T&gt; Members</a></dd>
<dt>Also in</dt>
<dd>Opc.UaFx.Client</dd>
</dl>

Defines a subclass for data types which are programmatically not inheritable.

## Syntax

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

```csharp
public interface IOpcData<T>
```

</div>

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

```vbnet
Public Interface IOpcData(Of T)
```

</div>

## Type parameters

| Name | Description |
|---|---|
| `T` | The [Type](https://learn.microsoft.com/dotnet/api/system.type) the data type derives from. The [Type](https://learn.microsoft.com/dotnet/api/system.type) of `T` have to be a built-in and native encodable data type (see [IsSystemType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#issystemtype)). |

## Remarks

Use this interface in case where e.g. a subclass of [int](https://learn.microsoft.com/dotnet/api/system.int32) or [string](https://learn.microsoft.com/dotnet/api/system.string) is to be defined. Such a data type needs to provide a public accessible default constructor (= without any parameters) to use the data type as subclass of `T`. Additionally consider implementing implicit cast operators from `T` to the subsclass and vice versa.

## Properties

| Name | Description |
|---|---|
| [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdata-1/members#value) | Gets or sets the data of the data type derived from. |

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.25–v2.59 |