OPC Studio User's Guide and Reference
IsNullable Property (IValueControl)



OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.ComponentModel Namespace > IValueControl Interface : IsNullable Property
Determines whether the interactive user of the control can set the value to null.
Syntax
'Declaration
 
ReadOnly Property IsNullable As Boolean
'Usage
 
Dim instance As IValueControl
Dim value As Boolean
 
value = instance.IsNullable
bool IsNullable {get;}
property bool IsNullable {
   bool get();
}
Remarks

The control's value can be null even in controls that are not nullable (their IsNullable is false).

The default value of this property must be equal to the corresponding OpcLabs.BaseLib.Annotations.ValueControlAttribute.DefaultNullable value.

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