问题
I have some code written in VB that reads as follows:
Return (Not (crc32Result))
I am trying to convert it to C#, and this is what I have:
return (!(crc32Result));
However I get a compiler error:
Compiler Error Message: CS0023: Operator '!' cannot be applied to operand of type 'uint'
Is there a different operator I need to be using instead of this one?
Thanks!
回答1:
It looks like what you are trying to do is reverse the bits of crc32result. If so, you want the tilde operator ~.
return (~crc32Result);
Reference this question.
回答2:
In C#, the bang(!) is used to flip a boolean variable. Are you trying to treat the uInt above as a boolean, or perform some other reversal (reversal of all binary digits, perhaps)?
I'd suggest one of these is the solution you're looking for:
return (!(bool)crc32Result); // treating as bool (0 = false, anything else is true)
return (~crc32Result); //bitwise flipping for all
回答3:
Try this:
return crc32Result == 0;
Or to be a little clearer on what I'm doing:
return !(crc32Result != 0);
What the second example does is convert it to boolean by the principal of "0 is false, non-zero is true". So if it's not equal to zero, it will return true. And then I use the '!' operator to do the "not" operation. The Visual Basic code you gave apparently does the first part implicitly (as will C/C++), but C# and Java won't.
But this is if and ONLY if you're looking for a boolean return type from the function. If you're doing a bit-wise inversion, then you need the following:
return (~crc32Result);
In that case, the '~' operator does the conversion to the other bit pattern.
来源：https://stackoverflow.com/questions/1179574/how-do-you-return-not-uint-in-c