VB.NET - Nullable DateTime and Ternary Operator -

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i'm having problems nullable datetime in vb.net (vs 2010).

method 1

if string.isnullorempty(lastcalibrationdatetextbox.text)     gauge.lastcalibrationdate = nothing else     gauge.lastcalibrationdate = datetime.parse(lastcalibrationdatetextbox.text) end if

method 2

gauge.lastcalibrationdate = if(string.isnullorempty(lastcalibrationdatetextbox.text), nothing, datetime.parse(lastcalibrationdatetextbox.text))

when given empty string method 1 assigns null (nothing) value gauge.lastcalibrationdate method 2 assigns datetime.minvalue.

in other places in code have:

lastcalibrationdate = if(isdbnull(dr("lastcalibrationdate")), nothing, dr("lastcalibrationdate"))

this correctly assigns null (nothing) ternary operator nullable datetime.

what missing? thanks!

i admit i'm not expert on this, apparently stems 2 things:

  1. the if ternary operator can return 1 type, in case date type, not nullable date type
  2. the vb.net nothing value not null equivalent default value of specified type, in case date, not nullable date. hence date minimum value.

i derived of information answer post: ternary operator vb vs c#: why resolves integer , not integer?

hope helps , joel coehoorn can shed more light on subject.


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