DynamicMethod.GetILGenerator Method (Int32)

Parameters

• streamSize
  Type: System.Int32
  The size of the MSIL stream, in bytes.

Return Value

Type: System.Reflection.Emit.ILGenerator
An ILGenerator object for the method, with the specified MSIL stream size.

' Create an array that specifies the parameter types of the
' overload of String.Format to be used in Hello.
Dim formatStringArgs() As Type = { GetType(String), GetType(Object), _
                           GetType(Object), GetType(Object) }
Dim formatString As MethodInfo = GetType(String). _
    GetMethod("Format", formatStringArgs)

' Get an ILGenerator and emit a body for the dynamic method,
' using a stream size larger than the IL that will be
' emitted.
Dim il As ILGenerator = hello.GetILGenerator(256)
' Push the format string for String.Format on the stack.
il.Emit(OpCodes.Ldstr, "Hello, {0}, {1} squared is {2}!")
' Load the first argument, which is a string, onto the stack,
' as the second argument of String.Format.
il.Emit(OpCodes.Ldarg_0)
' Load the second argument, and box it. This is the third argument
' of String.Format, and because it is a value type it must be boxed
' in order to pass it as an object.
il.Emit(OpCodes.Ldarg_1)
il.Emit(OpCodes.Box, GetType(Integer))
' Load the second argument twice more, as the arguments of the 
' multiply operation that will square it. 
il.Emit(OpCodes.Ldarg_1)
il.Emit(OpCodes.Ldarg_1)
' Multiply the last two arguments on the stack, leaving the 
' result on the stack. The result must be boxed, so it can be passed
' as the fourth argument of String.Format.
il.Emit(OpCodes.Mul)
il.Emit(OpCodes.Box, GetType(Integer))
' Call the overload of String.Format that prints a string, formatting
' it to include the next three objects on the stack.
il.Emit(OpCodes.Call, formatString)
' The Hello method returns the formatted string, which is already
' on the stack after the call to String.Format.
il.Emit(OpCodes.Ret)

// Create an array that specifies the parameter types of the
// overload of String.Format to be used in Hello.
Type[] formatStringArgs = { typeof(string), typeof(object), typeof(object), 
                           typeof(object) };
// Get the overload of String.Format that has one String 
// parameter for the format, and three object parameters.
MethodInfo formatString = typeof(String).GetMethod("Format",
    formatStringArgs);

// Get an ILGenerator and emit a body for the dynamic method,
// using a stream size larger than the IL that will be
// emitted.
ILGenerator il = hello.GetILGenerator(256);
// Push the format string for String.Format on the stack.
il.Emit(OpCodes.Ldstr, "Hello, {0}, {1} squared is {2}!");
// Load the first argument, which is a string, onto the stack,
// as the second argument of String.Format.
il.Emit(OpCodes.Ldarg_0);
// Load the second argument, and box it. This is the third argument
// of String.Format, and because it is a value type it must be boxed
// in order to pass it as an object.
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Box, typeof(int));
// Load the second argument twice more, as the arguments of the 
// multiply operation that will square it. 
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Ldarg_1);
// Multiply the last two arguments on the stack, leaving the 
// result on the stack. The result must be boxed, so it can be passed
// as the fourth argument of String.Format.
il.Emit(OpCodes.Mul);
il.Emit(OpCodes.Box, typeof(int));
// Call the overload of String.Format that prints a string, formatting
// it to include the next three objects on the stack.
il.Emit(OpCodes.Call, formatString);
// The Hello method returns the formatted string, which is already
// on the stack after the call to String.Format.
il.Emit(OpCodes.Ret);