class 关键字用于声明 类。
class
abstract
as
base
bool
break
byte
case
catch
char
checked
const
continue
decimal
default
delegate
do
double
else
enum
event
explicit
extern
false
finally
fixed
float
for
foreach
goto
if
implicit
in
int
interface
internal
is
lock
long
namespace
new
null
object
operator
out
override
params
private
protected
public
readonly
ref
return
sbyte
sealed
short
sizeof
stackalloc
static
string
struct
switch
this
throw
true
try
typeof
uint
ulong
unchecked
unsafe
ushort
using
var
virtual
void
volatile
while
add
alias
async
await
dynamic
get
global
nameof
partial
remove
set
value
when
where
yield
ascending
by
descending
equals
from
group
into
join
let
on
orderby
select