C# EmitContext.CloseConditionalAccess方法代码示例

		public override void EmitStatement (EmitContext ec)
		{
			if (conditionalAccessReceiver) {
				ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ()) {
					Statement = true
				};
			}

			var call = new CallEmitter ();
			call.InstanceExpression = InstanceExpr;
			call.EmitStatement (ec, method, arguments, loc);

			if (conditionalAccessReceiver)
				ec.CloseConditionalAccess (null);
		}

		public override void Emit (EmitContext ec)
		{
			if (conditional_access_receiver)
				ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ());

			if (method_group.InstanceExpression == null) {
				ec.EmitNull ();
			} else {
				var ie = new InstanceEmitter (method_group.InstanceExpression, false);
				ie.Emit (ec, method_group.ConditionalAccess);
			}

			var delegate_method = method_group.BestCandidate;

			// Any delegate must be sealed
			if (!delegate_method.DeclaringType.IsDelegate && delegate_method.IsVirtual && !method_group.IsBase) {
				ec.Emit (OpCodes.Dup);
				ec.Emit (OpCodes.Ldvirtftn, delegate_method);
			} else {
				ec.Emit (OpCodes.Ldftn, delegate_method);
			}

			ec.Emit (OpCodes.Newobj, constructor_method);

			if (conditional_access_receiver)
				ec.CloseConditionalAccess (null);
		}

//.........这里部分代码省略.........
				}
			} else {
				d = null;
			}

			var site_type_decl = new GenericTypeExpr (module.PredefinedTypes.CallSiteGeneric.TypeSpec, new TypeArguments (del_type), loc);
			var field = site_container.CreateCallSiteField (site_type_decl, loc);
			if (field == null)
				return;

			if (del_type_instance_access == null) {
				var dt = d.CurrentType.DeclaringType.MakeGenericType (module, context_mvars.Types);
				del_type_instance_access = new TypeExpression (MemberCache.GetMember (dt, d.CurrentType), loc);
			}

			var instanceAccessExprType = new GenericTypeExpr (module.PredefinedTypes.CallSiteGeneric.TypeSpec,
				new TypeArguments (del_type_instance_access), loc);

			if (instanceAccessExprType.ResolveAsType (ec.MemberContext) == null)
				return;

			bool inflate_using_mvar = context_mvars != null && ec.IsAnonymousStoreyMutateRequired;

			TypeSpec gt;
			if (inflate_using_mvar || context_mvars == null) {
				gt = site_container.CurrentType;
			} else {
				gt = site_container.CurrentType.MakeGenericType (module, context_mvars.Types);
			}

			// When site container already exists the inflated version has to be
			// updated manually to contain newly created field
			if (gt is InflatedTypeSpec && site_container.AnonymousMethodsCounter > 1) {
				var tparams = gt.MemberDefinition.TypeParametersCount > 0 ? gt.MemberDefinition.TypeParameters : TypeParameterSpec.EmptyTypes;
				var inflator = new TypeParameterInflator (module, gt, tparams, gt.TypeArguments);
				gt.MemberCache.AddMember (field.InflateMember (inflator));
			}

			FieldExpr site_field_expr = new FieldExpr (MemberCache.GetMember (gt, field), loc);

			BlockContext bc = new BlockContext (ec.MemberContext, null, ec.BuiltinTypes.Void);

			Arguments args = new Arguments (1);
			args.Add (new Argument (binder));
			StatementExpression s = new StatementExpression (new SimpleAssign (site_field_expr, new Invocation (new MemberAccess (instanceAccessExprType, "Create"), args)));

			using (ec.With (BuilderContext.Options.OmitDebugInfo, true)) {

				var conditionalAccessReceiver = IsConditionalAccessReceiver;
				var ca = ec.ConditionalAccess;

				if (conditionalAccessReceiver) {
					ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ()) {
						Statement = isStatement
					};

					//
					// Emit conditional access expressions before dynamic call
					// is initialized. It pushes site_field_expr on stack before
					// the actual instance argument is emited which would cause
					// jump from non-empty stack.
					//
					EmitConditionalAccess (ec);
				}

				if (s.Resolve (bc)) {
					Statement init = new If (new Binary (Binary.Operator.Equality, site_field_expr, new NullLiteral (loc)), s, loc);
					init.Emit (ec);
				}

				args = new Arguments (1 + dyn_args_count);
				args.Add (new Argument (site_field_expr));
				if (arguments != null) {
					int arg_pos = 1;
					foreach (Argument a in arguments) {
						if (a is NamedArgument) {
							// Name is not valid in this context
							args.Add (new Argument (a.Expr, a.ArgType));
						} else {
							args.Add (a);
						}

						if (inflate_using_mvar && a.Type != targs[arg_pos].Type)
							a.Expr.Type = targs[arg_pos].Type;

						++arg_pos;
					}
				}

				var target = new DelegateInvocation (new MemberAccess (site_field_expr, "Target", loc).Resolve (bc), args, false, loc).Resolve (bc);
				if (target != null) {
					target.Emit (ec);
				}

				if (conditionalAccessReceiver) {
					ec.CloseConditionalAccess (!isStatement && type.IsNullableType ? type : null);
					ec.ConditionalAccess = ca;
				}
			}
		}