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



OpcLabs.BaseLib Assembly > OpcLabs.BaseLib Namespace > ObjectDescriptor Class : IsNull Property
Determines whether the object descriptor is null.
Syntax
'Declaration
 
<DebuggerBrowsableAttribute(DebuggerBrowsableState.Never)>
<DefaultValueAttribute(True)>
Public Shadows ReadOnly Property IsNull As Boolean
'Usage
 
Dim instance As ObjectDescriptor
Dim value As Boolean
 
value = instance.IsNull
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
[DefaultValue(true)]
public new bool IsNull {get;}
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
[DefaultValue(true)]
public:
new property bool IsNull {
   bool get();
}

Property Value

Returns true if this object descriptor is null; otherwise, returns false.
Remarks
An object descriptor is considered empty when it has its initial scheme, the remaining parts of the URL string are empty, and both ObjectId and MachineName are empty.

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