CIL问题：！0是什么意思

Question

我有以下代码：

.method public hidebysig static int32  f(int32 g,
                                        string h,
                                        int32 i) cil managed
{
// Code size       62 (0x3e)
.maxstack  3
.locals init (class Program.IOp`1<int32> V_0,
        bool V_1,
        int32 V_2)
IL_0000:  nop
                        // Instantiating a Dictionary
IL_0001:  ldsfld     class [System.Collections]System.Collections.Generic.Dictionary`2<string,class Program.IOp`1<int32>> Program.Program::a  //Iniatlize Dictionary
IL_0006:  ldarg.1     // Load arguments passed onto function

// Check if a key is found and returns true or false
IL_0007:  callvirt   instance bool class [System.Collections]System.Collections.Generic.Dictionary`2<string,class Program.IOp`1<int32>>::ContainsKey(!0)
IL_000c:  ldc.i4.0    // Loads constant value 0
IL_000d:  ceq         // Checks if value returned @ IL_007 == the value loaded @ IL_007c. If it equals push 1, else push 0.
                        // So check if IL_007 == 0
IL_000f:  stloc.1     // Save result of ceq at local variable 1 V_1
IL_0010:  ldloc.1     // load V_1
IL_0011:  brfalse.s  IL_0025  // If V_1 == 0 Jump/Branch to IL_0025 else keep going
                                // So If it doesn't contatin key jump/branch to IL_0025
IL_0013:  nop
IL_0014:  ldstr      "Unknown command '{0}'"    // Push string to stack
IL_0019:  ldarg.1                               // Load arguments passed to function

// Loads arguments passed on to function and concatenates them at the end of the Unkown command string;  Replaces '{0}'
IL_001a:  call       string [System.Runtime]System.String::Format(string,
                                                                    object)
                        // Instantiating a Dictionary
IL_001f:  newobj     instance void [System.Runtime]System.ArgumentException::.ctor(string) // Initializing string object with string from prior call
IL_0024:  throw     // Throw exception created in IL_001f
IL_0025:  ldsfld     class [System.Collections]System.Collections.Generic.Dictionary`2<string,class Program.IOp`1<int32>> Program.Program::a
IL_002a:  ldarg.1   
IL_002b:  callvirt   instance !1 class [System.Collections]System.Collections.Generic.Dictionary`2<string,class Program.IOp`1<int32>>::get_Item(!0)
IL_0030:  stloc.0   // Store at local variable 0
IL_0031:  ldloc.0   // Load local variable 0
IL_0032:  ldarg.0   // Load arguments initializaed in function V_0, V_1, V_2
IL_0033:  ldarg.2   // Load arguments... Where From ?
IL_0034:  callvirt   instance !0 class Program.IOp`1<int32>::A(!0,
                                                                !0)  //What is happening here?
IL_0039:  stloc.2   // Store values from IL_0034 @ local variable 2, V_2
IL_003a:  br.s       IL_003c  // jump/branch to IL_003c
IL_003c:  ldloc.2   // Load value @ V_2
IL_003d:  ret       // Return V_2
} // end of method Program::f

我想知道！0传递给函数时是什么意思，可能还需要弄清代码的作用。

什么是类Program.IOp`1 V_0初始化？是结构吗？

IL_002b在做什么？

IL_0034在做什么？

随时纠正我在代码注释中犯的任何错误或误解。