AF SDK Reference

PIPoint.UnloadAllAttributes Method

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PIPoint.UnloadAllAttributes Method

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Last UpdatedNov 18, 2025
5 minute read

Unload all PIPoint attributes from the cache except for the specified names.

Namespace: OSIsoft.AF.PI
Assembly: OSIsoft.AFSDK (in OSIsoft.AFSDK.dll) Version: 3.1.1.1182

Syntax

public void UnloadAllAttributes(
	params string[] exceptNames
)

Public Sub UnloadAllAttributes ( 
	ParamArray exceptNames As String()
)

Dim instance As PIPoint
Dim exceptNames As String()

instance.UnloadAllAttributes(exceptNames)

public:
void UnloadAllAttributes(
	... array<String^>^ exceptNames
)

member UnloadAllAttributes : 
        exceptNames : string[] -> unit

Parameters

exceptNames: Type: SystemString
The list of attribute names not to unload. If or an empty list, then all attributes will be unloaded. The PICommonPointAttributes class contains some of the common PIPoint attribute names.

Remarks

All PIPoint attribute are unloaded from the client's cache except for the specified list of attributes not to unload. This method is used to free memory when PIPoint attributes are no longer needed, but the PIPoint is still being used. Note that ID, Name, PointType, Step, and Future attributes are not unloaded from the cache.

Examples

// This example demonstrates how to create an attribute for an
// element and retrieve and set PIPoint attributes.

// Get the Database
PISystems myPISystems = new PISystems();
PISystem myPISystem = myPISystems.DefaultPISystem;
AFDatabase myDB = myPISystem.Databases.DefaultDatabase;

// Create an Element Template
AFElementTemplate myElemTemplate = myDB.ElementTemplates.Add("MyElementTemplate");
AFAttributeTemplate myAttrTemplate = myElemTemplate.AttributeTemplates.Add("Attr#1");
myAttrTemplate.DataReferencePlugIn = AFDataReference.GetPIPointDataReference(myPISystem);
myAttrTemplate.ConfigString = @"\\%Server%\%Element%;pointtype=Float64";

// Create an Element from the Element Template
AFElement myElement = myDB.Elements.Add("MyElement", myElemTemplate);

// Create the PIPoint for the Attribute
AFAttribute myAttribute = myElement.Attributes["Attr#1"];
myAttribute.DataReference.CreateConfig();

// Find all PIPoint Attributes and Display their values
object drAttrValue;
myAttribute.PIPoint.LoadAttributes();
IEnumerable<string> list = myAttribute.PIPoint.FindAttributeNames(null);
Console.WriteLine("Found PIPoint Attributes: nameFilter='<null>'");
foreach (string item in list)
{
    drAttrValue = myAttribute.PIPoint.GetAttribute(item);
    Console.WriteLine("  {0} = '{1}'", item, drAttrValue);
}
Console.WriteLine();

// Find PIPoint Attributes matching 'Ex*' and display their values
list = myAttribute.PIPoint.FindAttributeNames("Ex*");
Console.WriteLine("Found PIPoint Attributes: nameFilter='Ex*'");
int cnt = 0;
foreach (string item in list)
{
    cnt++;
    drAttrValue = myAttribute.PIPoint.GetAttribute(item);
    Console.WriteLine("  {0} = '{1}'", item, drAttrValue);
}
Console.WriteLine();

// Unload all PIPoint Attributes
myAttribute.PIPoint.UnloadAllAttributes();

// Load specific PIPoint Attributes and display their values
myAttribute.PIPoint.LoadAttributes(PICommonPointAttributes.PointType,
    PICommonPointAttributes.PointID,
    PICommonPointAttributes.Descriptor,
    PICommonPointAttributes.ExtendedDescriptor,
    PICommonPointAttributes.CreationDate);
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.PointType);
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.PointType, drAttrValue);
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.PointID);
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.PointID, drAttrValue);
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.Descriptor);
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.Descriptor, drAttrValue);
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.ExtendedDescriptor);
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.ExtendedDescriptor, drAttrValue);
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.CreationDate);
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.CreationDate, drAttrValue);
Console.WriteLine();

// Set PIPoint Attribute value
string newAttrValue = "New Value: " + DateTime.Now.ToShortTimeString();
myAttribute.PIPoint.SetAttribute(PICommonPointAttributes.Descriptor, newAttrValue);
myAttribute.PIPoint.SetAttribute(PICommonPointAttributes.ExtendedDescriptor, newAttrValue);
AFErrors<string> errors = myAttribute.PIPoint.SaveAttributes(PICommonPointAttributes.Descriptor,
    PICommonPointAttributes.ExtendedDescriptor);
if (errors != null && errors.HasErrors)
{
    Console.WriteLine("Errors calling PIPoint.SaveAttributes:");
    foreach (var item in errors.Errors)
    {
        Console.WriteLine("  {0}: {1}", item.Key, item.Value);
    }
}

' This example demonstrates how to create an attribute for an
' element and retrieve and set PIPoint attributes.

' Get the Database
Dim myPISystems As PISystems = New PISystems
Dim myPISystem As PISystem = myPISystems.DefaultPISystem
Dim myDB As AFDatabase = myPISystem.Databases.DefaultDatabase

' Create an Element Template
Dim myElemTemplate As AFElementTemplate = myDB.ElementTemplates.Add("MyElementTemplate")
Dim myAttrTemplate As AFAttributeTemplate = myElemTemplate.AttributeTemplates.Add("Attr#1")
myAttrTemplate.DataReferencePlugIn = AFDataReference.GetPIPointDataReference(myPISystem)
myAttrTemplate.ConfigString = "\\%Server%\%Element%;pointtype=Float64"

' Create an Element from the Element Template
Dim myElement As AFElement = myDB.Elements.Add("MyElement", myElemTemplate)

' Create the PIPoint for the Attribute
Dim myAttribute As AFAttribute = myElement.Attributes("Attr#1")
myAttribute.DataReference.CreateConfig()

' Find all PIPoint Attributes and Display their values
Dim drAttrValue As Object
myAttribute.PIPoint.LoadAttributes()
Dim list As IEnumerable(Of String) = myAttribute.PIPoint.FindAttributeNames(Nothing)
Console.WriteLine("Found PIPoint Attributes: nameFilter='<null>'")
For Each item As String In list
    drAttrValue = myAttribute.PIPoint.GetAttribute(item)
    Console.WriteLine("  {0} = '{1}'", item, drAttrValue)
Next
Console.WriteLine()

' Find PIPoint Attributes matching 'Ex*' and display their values
list = myAttribute.PIPoint.FindAttributeNames("Ex*")
Console.WriteLine("Found PIPoint Attributes: nameFilter='Ex*'")
Dim cnt As Integer = 0
For Each item As String In list
    cnt = (cnt + 1)
    drAttrValue = myAttribute.PIPoint.GetAttribute(item)
    Console.WriteLine("  {0} = '{1}'", item, drAttrValue)
Next
Console.WriteLine()

' Unload all PIPoint Attributes
myAttribute.PIPoint.UnloadAllAttributes()

' Load specific PIPoint Attributes and display their values
myAttribute.PIPoint.LoadAttributes(PICommonPointAttributes.PointType,
                                   PICommonPointAttributes.PointID,
                                   PICommonPointAttributes.Descriptor,
                                   PICommonPointAttributes.ExtendedDescriptor,
                                   PICommonPointAttributes.CreationDate)
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.PointType)
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.PointType, drAttrValue)
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.PointID)
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.PointID, drAttrValue)
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.Descriptor)
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.Descriptor, drAttrValue)
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.ExtendedDescriptor)
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.ExtendedDescriptor, drAttrValue)
drAttrValue = myAttribute.PIPoint.GetAttribute(PICommonPointAttributes.CreationDate)
Console.WriteLine("PIPoint Attribute '{0}' = '{1}'.", PICommonPointAttributes.CreationDate, drAttrValue)
Console.WriteLine()

' Set PIPoint Attribute value
Dim newAttrValue As String = ("New Value: " + DateTime.Now.ToShortTimeString)
myAttribute.PIPoint.SetAttribute(PICommonPointAttributes.Descriptor, newAttrValue)
myAttribute.PIPoint.SetAttribute(PICommonPointAttributes.ExtendedDescriptor, newAttrValue)
Dim errors As AFErrors(Of String) = myAttribute.PIPoint.SaveAttributes(PICommonPointAttributes.Descriptor,
                                                                       PICommonPointAttributes.ExtendedDescriptor)
If errors IsNot Nothing AndAlso errors.HasErrors Then
    Console.WriteLine("Errors calling PIPoint.SaveAttributes:")
    For Each item As KeyValuePair(Of String, Exception) In errors.Errors
        Console.WriteLine("  {0}: {1}", item.Key, item.Value)
    Next
End If

No code example is currently available or this language may not be supported.

AF SDK Reference