TCalendarView returning a bad Date

[Andrew Spencer 2]

A TCalendarView on a TForm, with a TMemo. In the TCalendarView's OnClick event, add a line to the TMemo showing when the OnClick event happened, and the formatted and integer value of TCalendarView.Date.

 

In Delphi 10.4.2 I am seeing that with consecutive <1Hz clicking on the same date, a "bad" date value is returned on every second click returns a null date. Also, when clicking >~1Hz, this can produce multiple "bad" dates.

 

The "bad" date value is -700000 (if you take the Trunc() of it).

 

Does anyone have any ideas?

TCalendarViewBadDate.zip

Edited July 4, 2023 by Andrew Spencer

[Uwe Raabe 1891]

I'm a bit unsure what your example should achieve, as it doesn't match what you show here.

[Lajos Juhász 240]

I can confirm using both OnClick and OnChange events that I can receive:

45113
-700000
45113
-700000
45113
-700000
45113
-700000
45113
-700000
45113
-700000
45113
-700000
45113
-700000
45113
-700000
45113
-700000
45113
-700000
 

[Andrew Spencer 2]

Apologies - I zipped up the wrong one.

TCalendarViewInvalidDate.zip

[Uwe Raabe 1891]

I guess, that is as designed. When you click on a date that date is selected. When you click again on the same date it is unselected and the Date property is set to NullDate:

  NullDate: TDate = -700000;

You can avoid that when you set SelectionMode to smNone.

[Andrew Spencer 2]

Ouch! OK - that makes sense. I'll have to do a work-around for how I want it to behave.

Thanks, Uwe.