Yoctopuce Yocto-Display, User Manual

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22. High-level API Reference
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YFiles
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registerValueCallback()
Registers the callback function that is invoked on every change of advertised value.
js
function registerValueCallback( callback )
cpp
int registerValueCallback( YFilesValueCallback callback )
m
-(int) registerValueCallback : (YFilesValueCallback) callback
pas
function registerValueCallback( callback : TYFilesValueCallback): LongInt
vb
function registerValueCallback( ) As Integer
cs
int registerValueCallback( ValueCallback callback )
java
int registerValueCallback( UpdateCallback callback )
uwp
Task<int> registerValueCallback( ValueCallback callback )
py
def registerValueCallback( callback )
php
function registerValueCallback( $callback )
es
function registerValueCallback( callback )
The callback is invoked only during the execution of
ySleep
or
yHandleEvents
. This provides
control over the time when the callback is triggered. For good responsiveness, remember to call one of
these two functions periodically. To unregister a callback, pass a null pointer as argument.
Parameters :
callback the callback function to call, or a null pointer. The callback function should take two arguments:
the function object of which the value has changed, and the character string describing the new
advertised value.