Rectangle Properties comparison in c++ Windows Form and WPF

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Hello Everyone
In Windows forms a rectangle variable name is used in a "if Statement" and it returns a Boolean values as such:

if (someRectangle)
if (!someRectangle)

or a rectangle is nulled as such:

someRectangle = nullptr;

Would you please describe the following:
-What property of the rectangle we are evaluating in these if statements, is it if exist, enabled, initialized, nonempty or ...?
-What happens when a rectangle is set equal to nullptr? is it disabled or ...?
-What is the equivalent of these "if statements" and "rectangle=nullptr" in WPF (c#)?

Posted 17-May-12 4:46am

Member 8456258

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Richard MacCutchan · Accepted Answer · 2012-05-17T04:58:00

Solution 1

This test merely checks whether the rectangle refers to an object or not. It has no effect on any of the properties in the case that the object exists. This holds true in all the three situations you have asked about.

Posted 17-May-12 4:58am

Richard MacCutchan

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Member 8456258 17-May-12 20:49pm

How do you check whether the rectangle refers to an object or not in C#. How do you cancel that pointer to the object in c#.

Richard MacCutchan 18-May-12 4:12am

You already have it: if (someRectangle == null) .... If the reference is not null then it points to an object. Generally speaking you do not need to worry about cancelling it unless you make explicit calls to its dispose() method. In some cases you can protect your code from inadvertent references to non-existent objects by putting blocks of code within using {} blocks.

Member 8456258 18-May-12 10:19am

Thanks!