'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function WriteValueFunction(Of TValue)( _
   ByVal dataVariable As UADataVariable, _
   ByVal dataTypeId As UANodeId, _
   ByVal writeValueFunction As Func(Of TValue,UAStatusCode) _
) As UADataVariable

'Usage
 
Dim dataVariable As UADataVariable
Dim dataTypeId As UANodeId
Dim writeValueFunction As Func(Of TValue,UAStatusCode)
Dim value As UADataVariable
 
value = UADataVariableExtension.WriteValueFunction(Of TValue)(dataVariable, dataTypeId, writeValueFunction)

[Extension()]
[NotNull()]
public static UADataVariable WriteValueFunction<TValue>( 
   UADataVariable dataVariable,
   UANodeId dataTypeId,
   Func<TValue,UAStatusCode> writeValueFunction
)

[Extension()]
[NotNull()]
public:
static UADataVariable^ WriteValueFunctiongeneric<typename TValue>
( 
   UADataVariable^ dataVariable,
   UANodeId^ dataTypeId,
   Func<TValue^,UAStatusCode^>^ writeValueFunction
) 

Parameters

dataVariable

The data variable that will be modified and returned.

The value of this parameter cannot be null (Nothing in Visual Basic).

dataTypeId

Specifies the OPC UA data type of the variable value. For standard data types, see OpcLabs.EasyOpc.UA.AddressSpace.Standard.UADataTypeIds.

Because the OpcLabs.EasyOpc.UA.AddressSpace.UANodeId has an implicit conversion from System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the expanded text of the nodeId) in place of this parameter, and the corresponding OPC UA node Id will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.AddressSpace.UANodeId.UANodeId Constructor(String) constructor instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

writeValueFunction

The write value function, i.e. the function that accepts the value to be written, performs the write operation, and returns the status code that is the result of the OPC UA Write.

The value of this parameter cannot be null (Nothing in Visual Basic).

Type Parameters

TValue

Return Value

The type used in your code to implement the data variable behavior is TValue, and it can be different from the OPC data type specified by the dataTypeId parameter. OPC Wizard provides automatic value conversions. This can be useful in case your language makes it more difficult to process some .NET types, as is the case e.g. with VB.NET and unsigned integer types such as System.UInt32. In this case, for example, if you want a data variable of OPC type UInt32, you can set dataTypeId to OpcLabs.EasyOpc.UA.AddressSpace.Standard.UADataTypeIds.UInt32, but use a System.Int64 as the return type of your function (TValue).

The writeValueFunction is allowed to return null, which is interpreted as a "Good" status code.

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows