This is more a question I'm asking to understand rather than figure 开发者_如何学Cout a problem. Consider the following two:
[Flags]
public enum Flags
{
NONE = 0x0,
PASSUPDATE = 0x1,
PASSRENDER = 0x2,
DELETE = 0x4,
ACCEPTINPUT = 0x8,
FADE_IN = 0x10,
FADE_OUT = 0x20,
FADE_OUT_COMPLETE = 0x40
}
[Flags]
public enum Flags
{
NONE = 0x0,
PASSUPDATE,
PASSRENDER,
DELETE,
ACCEPTINPUT,
FADE_IN ,
FADE_OUT,
FADE_OUT_COMPLETE
}
If I do bit checking on something using the latter enum there sometimes is overlap (I think something like DELETE
is interpreted as PASSUPDATE | PASSRENDER
, while in the first example each entry is independent of the other (i.e. DELETE
is only DELETE
and cannot be proven using a combination of a different set of flags).
Without explicit numbers, enums increment by 1 each time (even with [Flags]
specified), so you get:
[Flags]
public enum Flags
{
NONE = 0x0,
PASSUPDATE, // = 1
PASSRENDER,// = 2
DELETE,// = 3
ACCEPTINPUT,// = 4
FADE_IN ,// = 5
FADE_OUT,// = 6
FADE_OUT_COMPLETE// = 7
}
which is simply not the numbers you wanted (and certainly isn't bitwise flags which are typically successive powers of 2)
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