Property Value
This value of this property can be null
(Nothing
in Visual Basic).
The value of this property cannot be null
(Nothing
in Visual Basic).
The default value of this property is "" (String.Empty)
.
This value of this property can be null
(Nothing
in Visual Basic).
The value of this property cannot be null
(Nothing
in Visual Basic).
The default value of this property is "" (String.Empty)
.
Exception | Description |
---|---|
System.ArgumentNullException |
A This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception. |
This value can be used as OpcLabs.BaseLib.ResourceDescriptor.UrlString.
A generic string is used instead of System.Uri, because in some cases, the value may not represent a real URI.
This value is derived from DiscoveryUriStrings. When DiscoveryUriStrings contains precisely one element, DiscoveryUriString is equal to value of this element. Otherwise, DiscoveryUriString is an empty string. Assigning a non-empty string to DiscoveryUriString clears the DiscoveryUriStrings and adds this string as a single element to the collection. Assigning an empty string to DiscoveryUriString has no effect.
Certain types of discovery queries, such as OpcLabs.EasyOpc.UA.Discovery.UALocalApplicationDiscoveryQuery or OpcLabs.EasyOpc.UA.Discovery.UALocalApplicationDiscoveryQuery with the Flat parameter set to true
always return application elements which have precisely one discovery URI, and in such case it is guaranteed that DiscoveryUriString contains a non-empty string.
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.