# OpcServiceRequest Class

> Reference: Defines the base class of the requests of the services of OPC UA, e.g. as passed to the Invoke method of a service.

<span class="api-meta">abstract</span>

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx.services">Opc.UaFx.Services</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">OpcServiceRequest Members</a></dd>
<dt>Also in</dt>
<dd>Opc.UaFx.Client</dd>
</dl>

Defines the base class of the requests of the services of OPC UA, e.g. as passed to the [Invoke](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.iopcservice-2/members#invoke) method of a service.

## Syntax

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

```csharp
public abstract class OpcServiceRequest
```

</div>

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

```vbnet
Public MustInherit Class OpcServiceRequest
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → **OpcServiceRequest**

## Implements

<ul class="api-implements">
<li><a href="../opc.uafx.services.iopcservicerequest/">IOpcServiceRequest</a></li>
</ul>

## Derived types

- [OpcBrowseNextRequest](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcbrowsenextrequest/)
- [OpcServiceRequest&lt;TCommand, TCommands&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest-2/)

## Constructors

| Name | Description |
|---|---|
| [OpcServiceRequest](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest/members#opcservicerequest)<span class="api-meta">protected · 2 overloads</span> | Initializes a new instance of the OpcServiceRequest class using a new header. |

## Properties

| Name | Description |
|---|---|
| [Header](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest/members#header) | Gets the header of the request. |
| [ServiceName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest/members#servicename)<span class="api-meta">since v2.19</span> | Gets the name of the service of the request. |

## Methods

| Name | Description |
|---|---|
| [CreateHeader](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest/members#createheader)<span class="api-meta">protected · since v2.7</span> | Creates the header of the request using [CreateHeaderCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest/members#createheadercore) and assigns it to the request. |
| [CreateHeaderCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest/members#createheadercore)<span class="api-meta">protected · virtual · since v2.7</span> | When overridden in a derived class, creates the header of the request. |
| [Validate](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.services.opcservicerequest/members#validate)<span class="api-meta">protected · virtual · since v2.50</span> | When overridden in a derived class, validates the request before a server processes it. |

## Applies to

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