Lightstreamer PCL (Portable Class Library) Client 3.1.0
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IUpdateInfo.IsValueChanged Method (string)

Asks whether the value for a field has changed after the reception of this update. For the first update for the item, it always returns true. 

If the "COMMAND logic" behaviour is enabled, then the change is meant as relative to the same key; as a consequence, on ADD commands the method always returns true; moreover, on DELETE commands the method returns true for all fields, but for the "key" field. 

 

C++
bool IsValueChanged(string fieldName);
C#
bool IsValueChanged(string fieldName);
Visual Basic
Function IsValueChanged(fieldName As string) As bool
Parameters 
Description 
string fieldName 
a field name. 

true if the updated value is different than the previous one, according to the above specifications.

Exceptions 
Description 
ArgumentException 
the specified field name does not represent a subscribed field; also thrown if a SimpleTableInfo was used to describe the related table.