# OpcCallMethodOptions Enum

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

Defines the different tasks that take place before and after calling a method node.

## Syntax

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

```csharp
public enum OpcCallMethodOptions
```

</div>

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

```vbnet
<Flags>
Public Enum OpcCallMethodOptions
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [ValueType](https://learn.microsoft.com/dotnet/api/system.valuetype) → [Enum](https://learn.microsoft.com/dotnet/api/system.enum) → **OpcCallMethodOptions**

## Fields

| Name | Value | Description |
|---|---|---|
| <a id="none"></a>`None` | `0` | The method node is called without any pre and post tasks. |
| <a id="verifyall"></a>`VerifyAll` | `VerifyExistence \| VerifyArguments \| VerifyResult` | The method node is tested on existing and the signature of its input and output arguments is verified against the OPC UA specification before calling the method node. After calling the method node the result values are also verified. This option combines [VerifyExistence](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyexistence), [VerifyArguments](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyarguments) and [VerifyResult](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyresult). |
| <a id="verifyallonce"></a>`VerifyAllOnce` | `VerifyCached \| VerifyAll` | Like [VerifyAll](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyall) but after a method has been called once its verifications wont be re-applied by subsequent method node calls. This option combines [VerifyCached](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifycached) and [VerifyAll](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyall). |
| <a id="verifyarguments"></a>`VerifyArguments` | `VerifyInputArguments \| VerifyOutputArguments` | The signature of all arguments (input and output) of the method node will be verified whether it matches the OPC UA specification before calling the method. Verifying the arguments does also include the verification on existence. This option combines [VerifyInputArguments](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyinputarguments) and [VerifyOutputArguments](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyoutputarguments). |
| <a id="verifyargumentsonce"></a>`VerifyArgumentsOnce` | `VerifyCached \| VerifyArguments` | Like [VerifyArguments](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyarguments) but after a method node has been called once its signature of the arguments wont be re-verified by subsequent method node calls. |
| <a id="verifycached"></a>`VerifyCached` | `1` | The method node metadata will be cached for subsequent calls while combined verifications will only take place by the first method node call. |
| <a id="verifyexistence"></a>`VerifyExistence` | `2` | The method node will be tested on existence before calling the method. |
| <a id="verifyexistenceonce"></a>`VerifyExistenceOnce` | `VerifyCached \| VerifyExistence` | Like [VerifyExistence](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyexistence) but after a method node has been called once it wont be re-tested by subsequent method node calls. |
| <a id="verifyinputarguments"></a>`VerifyInputArguments` | `4` | The signature of the input arguments of the method node will be verified whether it matches the OPC UA specification before calling the method. Verifying the input arguments does also include the verification on existence. |
| <a id="verifyinputargumentsonce"></a>`VerifyInputArgumentsOnce` | `VerifyCached \| VerifyInputArguments` | Like [VerifyInputArguments](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyinputarguments) but after a method node has been called once its signature of the input arguments wont be re-verified by subsequent method node calls. |
| <a id="verifyoutputarguments"></a>`VerifyOutputArguments` | `8` | The signature of the output arguments of the method node will be verified whether it matches the OPC UA specification before calling the method. Verifying the output arguments does also include the verification on existence. |
| <a id="verifyoutputargumentsonce"></a>`VerifyOutputArgumentsOnce` | `VerifyCached \| VerifyOutputArguments` | Like [VerifyOutputArguments](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyoutputarguments) but after a method node has been called once its signature of the output arguments wont be re-verified by subsequent method node calls. |
| <a id="verifyresult"></a>`VerifyResult` | `16` | The resulting values of the method node call are verified whether they match the OPC UA specification after calling the method node. |
| <a id="verifyresultonce"></a>`VerifyResultOnce` | `VerifyCached \| VerifyResult` | Like [VerifyResult](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opccallmethodoptions/#verifyresult) but after a method node has been called once its resulting values of the method call wont be re-verified by subsequent method node calls. |

## Applies to

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