System.Action<T1, T2, T3, T4, T5, T6, T7, T8, T9> public sealed delegate Action<T1, T2, T3, T4, T5, T6, T7, T8, T9> : MulticastDelegate Documentation Code namespace System { public delegate void Action<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9> (T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9); }