OPC Studio User's Guide and Reference
IsNull Property (_ResourceDescriptor)



OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.ComTypes Namespace > _ResourceDescriptor Interface : IsNull Property
Determines whether the resource descriptor is null.
Syntax
'Declaration
 
ReadOnly Property IsNull As Boolean
'Usage
 
Dim instance As _ResourceDescriptor
Dim value As Boolean
 
value = instance.IsNull
bool IsNull {get;}
property bool IsNull {
   bool get();
}

Property Value

The default value of this property is True.

Returns true if this resource descriptor is null; otherwise, returns false.
Remarks
A resource descriptor is considered null when UrlString is empty.

The getter method of this property is pure, i.e. it does not have observable side effects.

This member or type is for use from COM. It is not meant to be used from .NET or Python. Refer to the corresponding .NET member or type instead, if you are developing in .NET or Python.

This method or property does not throw any exceptions, aside from execution exceptions such as System.Threading.ThreadAbortException or System.OutOfMemoryException.

Requirements

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

See Also