In general, when you put a value type into an object
(called boxing) you need to unbox it to the exact same value type. You cannot do a conversion to another type instead. This is what happens here.
If you really want to convert the object, you first need to unbox it. Say your original value was a float
before you boxed it in an object
:
double d = (double) (float) value;
Or use the method proposed by others, which uses Convert
. This has the advantage that the original type doesn’t have to be known.
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