# OpcEventFilter Class

<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">OpcEventFilter Members</a></dd>
<dt>Also in</dt>
<dd>Opc.UaFx.Client</dd>
</dl>

Represents the filter of a monitored item for events, as defined by the EventFilter of OPC UA: the select clauses define the fields to report of each event and the where clause defines the events to report.

## Syntax

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

```csharp
public class OpcEventFilter : OpcMonitoringFilter
```

</div>

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

```vbnet
Public Class OpcEventFilter
    Inherits OpcMonitoringFilter
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [OpcMonitoringFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmonitoringfilter/) → **OpcEventFilter**

## Constructors

| Name | Description |
|---|---|
| [OpcEventFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventfilter/members#opceventfilter)<span class="api-meta">4 overloads</span> | Initializes a new instance of the OpcEventFilter class using the specified `selectClauses` and a where clause which does not restrict the events. |

## Properties

| Name | Description |
|---|---|
| [SelectClause](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventfilter/members#selectclause) | Gets the operands which select the fields to report of each event. |
| [WhereClause](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventfilter/members#whereclause) | Gets the filter which defines the events to report. |

## Applies to

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