# OpcCertificateQueryInstanceEventArgs Class

> Reference: Provides the event data for the QueryInstance event.

<span class="api-meta">since v2.7</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">OpcCertificateQueryInstanceEventArgs Members</a></dd>
<dt>Also in</dt>
<dd>Opc.UaFx.Client</dd>
</dl>

Provides the event data for the [QueryInstance](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatemanager/members#queryinstance) event.

## Syntax

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

```csharp
public class OpcCertificateQueryInstanceEventArgs : EventArgs
```

</div>

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

```vbnet
Public Class OpcCertificateQueryInstanceEventArgs
    Inherits EventArgs
```

</div>

## Inheritance

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

## Constructors

| Name | Description |
|---|---|
| [OpcCertificateQueryInstanceEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#opccertificatequeryinstanceeventargs)<span class="api-meta">6 overloads</span> | Initializes a new instance of the OpcCertificateQueryInstanceEventArgs class using the `path` of the certificate file to load when creating the [X509Certificate2](https://learn.microsoft.com/dotnet/api/system.security.cryptography.x509certificates.x509certificate2) instance representing the contents of the certificate file. |

## Properties

| Name | Description |
|---|---|
| [Certificate](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#certificate) | Gets or sets the [X509Certificate2](https://learn.microsoft.com/dotnet/api/system.security.cryptography.x509certificates.x509certificate2) instance created either from the [Path](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#path) or [RawData](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#rawdata) while using the [Password](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#password) and the [KeyStorage](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#keystorage) flags considering custom, platform and operating system related restrictions. |
| [KeyStorage](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#keystorage) | Gets the [X509KeyStorageFlags](https://learn.microsoft.com/dotnet/api/system.security.cryptography.x509certificates.x509keystorageflags) indicating the way the key in the certificate is to be stored after the certificate has been loaded. |
| [Password](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#password) | Gets the password to use when reading the certificate data. |
| [Path](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#path) | Gets the full qualified path of the certificate file to load. |
| [RawData](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccertificatequeryinstanceeventargs/members#rawdata) | Gets the binary information of the certificate to load. |

Inherits members from [EventArgs](https://learn.microsoft.com/dotnet/api/system.eventargs).

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.7–v2.59 |