C# CodeGenerator.MarkLabel方法代码示例

        //GenerateGetSerializer(serializers, xmlMappings);
        private void GenerateGetSerializer(Dictionary<string, string> serializers, XmlMapping[] xmlMappings, TypeBuilder serializerContractTypeBuilder)
        {
            ilg = new CodeGenerator(serializerContractTypeBuilder);
            ilg.BeginMethod(
                typeof(XmlSerializer),
                "GetSerializer",
                new Type[] { typeof(Type) },
                new string[] { "type" },
                CodeGenerator.PublicOverrideMethodAttributes);

            for (int i = 0; i < xmlMappings.Length; i++)
            {
                if (xmlMappings[i] is XmlTypeMapping)
                {
                    Type type = xmlMappings[i].Accessor.Mapping.TypeDesc.Type;
                    if (type == null)
                        continue;
                    if (!type.GetTypeInfo().IsPublic && !type.GetTypeInfo().IsNestedPublic)
                        continue;
                    // DDB172141: Wrong generated CS for serializer of List<string> type
                    if (type.GetTypeInfo().IsGenericType || type.GetTypeInfo().ContainsGenericParameters)
                        continue;
                    ilg.Ldarg("type");
                    ilg.Ldc(type);
                    ilg.If(Cmp.EqualTo);
                    {
                        ConstructorInfo ctor = CreatedTypes[(string)serializers[xmlMappings[i].Key]].GetConstructor(
                            CodeGenerator.InstanceBindingFlags,
                            Array.Empty<Type>()
                            );
                        ilg.New(ctor);
                        ilg.Stloc(ilg.ReturnLocal);
                        ilg.Br(ilg.ReturnLabel);
                    }
                    ilg.EndIf();
                }
            }
            ilg.Load(null);
            ilg.Stloc(ilg.ReturnLocal);
            ilg.Br(ilg.ReturnLabel);
            ilg.MarkLabel(ilg.ReturnLabel);
            ilg.Ldloc(ilg.ReturnLocal);
            ilg.EndMethod();
        }

        void WriteLiteralStructMethod(StructMapping structMapping) {
            string methodName = (string)MethodNames[structMapping];
            string typeName = structMapping.TypeDesc.CSharpName;
            ilg = new CodeGenerator(this.typeBuilder);
            List<Type> argTypes = new List<Type>();
            List<string> argNames = new List<string>();
            if (structMapping.TypeDesc.IsNullable) {
                argTypes.Add(typeof(Boolean));
                argNames.Add("isNullable");
            }
            argTypes.Add(typeof(Boolean));
            argNames.Add("checkType");
            ilg.BeginMethod(
                structMapping.TypeDesc.Type,
                GetMethodBuilder(methodName),
                argTypes.ToArray(),
                argNames.ToArray(),
                CodeGenerator.PrivateMethodAttributes);

            LocalBuilder locXsiType = ilg.DeclareLocal(typeof(XmlQualifiedName), "xsiType");
            LocalBuilder locIsNull = ilg.DeclareLocal(typeof(Boolean), "isNull");
            MethodInfo XmlSerializationReader_GetXsiType = typeof(XmlSerializationReader).GetMethod(
                "GetXsiType",
                CodeGenerator.InstanceBindingFlags,
                null,
                CodeGenerator.EmptyTypeArray,
                null
                );
            MethodInfo XmlSerializationReader_ReadNull = typeof(XmlSerializationReader).GetMethod(
                 "ReadNull",
                 CodeGenerator.InstanceBindingFlags,
                 null,
                 CodeGenerator.EmptyTypeArray,
                 null
                 );
            Label labelTrue = ilg.DefineLabel();
            Label labelEnd = ilg.DefineLabel();
            ilg.Ldarg("checkType");
            ilg.Brtrue(labelTrue);
            ilg.Load(null);
            ilg.Br_S(labelEnd);
            ilg.MarkLabel(labelTrue);
            ilg.Ldarg(0);
            ilg.Call(XmlSerializationReader_GetXsiType);
            ilg.MarkLabel(labelEnd);
            ilg.Stloc(locXsiType);
            ilg.Ldc(false);
            ilg.Stloc(locIsNull);
            if (structMapping.TypeDesc.IsNullable) {
                ilg.Ldarg("isNullable");
                ilg.If();
                {
                    ilg.Ldarg(0);
                    ilg.Call(XmlSerializationReader_ReadNull);
                    ilg.Stloc(locIsNull);
                }
                ilg.EndIf();
            }

            ilg.Ldarg("checkType");
            ilg.If(); // if (checkType)
            if (structMapping.TypeDesc.IsRoot) {
                ilg.Ldloc(locIsNull);
                ilg.If();
                ilg.Ldloc(locXsiType);
                ilg.Load(null);
                ilg.If(Cmp.NotEqualTo);
                MethodInfo XmlSerializationReader_ReadTypedNull = typeof(XmlSerializationReader).GetMethod(
                       "ReadTypedNull",
                       CodeGenerator.InstanceBindingFlags,
                       null,
                       new Type[] { locXsiType.LocalType },
                       null
                       );
                ilg.Ldarg(0);
                ilg.Ldloc(locXsiType);
                ilg.Call(XmlSerializationReader_ReadTypedNull);
                ilg.Stloc(ilg.ReturnLocal);
                ilg.Br(ilg.ReturnLabel);
                ilg.Else();
                if (structMapping.TypeDesc.IsValueType) {
                    throw CodeGenerator.NotSupported("Arg_NeverValueType");
                }
                else {
                    ilg.Load(null);
                    ilg.Stloc(ilg.ReturnLocal);
                    ilg.Br(ilg.ReturnLabel);
                }
                ilg.EndIf(); // if (xsiType != null)

                ilg.EndIf(); // if (isNull)
            }
            ilg.Ldloc(typeof(XmlQualifiedName), "xsiType");
            ilg.Load(null);
            ilg.Ceq();
            if (!structMapping.TypeDesc.IsRoot) {
                labelTrue = ilg.DefineLabel();
                labelEnd = ilg.DefineLabel();
                // xsiType == null
                ilg.Brtrue(labelTrue);
//.........这里部分代码省略.........

        internal string GenerateTypedSerializer(string readMethod, string writeMethod, XmlMapping mapping, CodeIdentifiers classes, string baseSerializer, string readerClass, string writerClass)
        {
            string serializerName = CodeIdentifier.MakeValid(Accessor.UnescapeName(mapping.Accessor.Mapping.TypeDesc.Name));
            serializerName = classes.AddUnique(serializerName + "Serializer", mapping);

            TypeBuilder typedSerializerTypeBuilder = CodeGenerator.CreateTypeBuilder(
                _moduleBuilder,
                CodeIdentifier.GetCSharpName(serializerName),
                TypeAttributes.Public | TypeAttributes.Sealed | TypeAttributes.BeforeFieldInit,
                CreatedTypes[baseSerializer],
                Array.Empty<Type>()
                );

            ilg = new CodeGenerator(typedSerializerTypeBuilder);
            ilg.BeginMethod(
                typeof(Boolean),
                "CanDeserialize",
                new Type[] { typeof(XmlReader) },
                new string[] { "xmlReader" },
                CodeGenerator.PublicOverrideMethodAttributes
            );

            if (mapping.Accessor.Any)
            {
                ilg.Ldc(true);
                ilg.Stloc(ilg.ReturnLocal);
                ilg.Br(ilg.ReturnLabel);
            }
            else
            {
                MethodInfo XmlReader_IsStartElement = typeof(XmlReader).GetMethod(
                     "IsStartElement",
                     CodeGenerator.InstanceBindingFlags,
                     new Type[] { typeof(String), typeof(String) }
                     );
                ilg.Ldarg(ilg.GetArg("xmlReader"));
                ilg.Ldstr(GetCSharpString(mapping.Accessor.Name));
                ilg.Ldstr(GetCSharpString(mapping.Accessor.Namespace));
                ilg.Call(XmlReader_IsStartElement);
                ilg.Stloc(ilg.ReturnLocal);
                ilg.Br(ilg.ReturnLabel);
            }
            ilg.MarkLabel(ilg.ReturnLabel);
            ilg.Ldloc(ilg.ReturnLocal);
            ilg.EndMethod();

            if (writeMethod != null)
            {
                ilg = new CodeGenerator(typedSerializerTypeBuilder);
                ilg.BeginMethod(
                    typeof(void),
                    "Serialize",
                    new Type[] { typeof(object), typeof(XmlSerializationWriter) },
                    new string[] { "objectToSerialize", "writer" },
                    CodeGenerator.ProtectedOverrideMethodAttributes);
                MethodInfo writerType_writeMethod = CreatedTypes[writerClass].GetMethod(
                    writeMethod,
                    CodeGenerator.InstanceBindingFlags,
                    new Type[] { (mapping is XmlMembersMapping) ? typeof(object[]) : typeof(object) }
                    );
                ilg.Ldarg("writer");
                ilg.Castclass(CreatedTypes[writerClass]);
                ilg.Ldarg("objectToSerialize");
                if (mapping is XmlMembersMapping)
                {
                    ilg.ConvertValue(typeof(object), typeof(object[]));
                }
                ilg.Call(writerType_writeMethod);
                ilg.EndMethod();
            }
            if (readMethod != null)
            {
                ilg = new CodeGenerator(typedSerializerTypeBuilder);
                ilg.BeginMethod(
                    typeof(object),
                    "Deserialize",
                    new Type[] { typeof(XmlSerializationReader) },
                    new string[] { "reader" },
                    CodeGenerator.ProtectedOverrideMethodAttributes);
                MethodInfo readerType_readMethod = CreatedTypes[readerClass].GetMethod(
                    readMethod,
                    CodeGenerator.InstanceBindingFlags,
                    Array.Empty<Type>()
                    );
                ilg.Ldarg("reader");
                ilg.Castclass(CreatedTypes[readerClass]);
                ilg.Call(readerType_readMethod);
                ilg.EndMethod();
            }
            typedSerializerTypeBuilder.DefineDefaultConstructor(CodeGenerator.PublicMethodAttributes);
            Type typedSerializerType = typedSerializerTypeBuilder.CreateTypeInfo().AsType();
            CreatedTypes.Add(typedSerializerType.Name, typedSerializerType);

            return typedSerializerType.Name;
        }

        void WriteNullableMethod(NullableMapping nullableMapping) {
            string methodName = (string)MethodNames[nullableMapping];
            ilg = new CodeGenerator(this.typeBuilder);
            ilg.BeginMethod(
                nullableMapping.TypeDesc.Type,
                GetMethodBuilder(methodName),
                new Type[] { typeof(Boolean) },
                new string[] { "checkType" },
                CodeGenerator.PrivateMethodAttributes);

            LocalBuilder oLoc = ilg.DeclareLocal(nullableMapping.TypeDesc.Type, "o");

            ilg.LoadAddress(oLoc);
            ilg.InitObj(nullableMapping.TypeDesc.Type);
            MethodInfo XmlSerializationReader_ReadNull = typeof(XmlSerializationReader).GetMethod(
                "ReadNull",
                CodeGenerator.InstanceBindingFlags,
                null,
                CodeGenerator.EmptyTypeArray,
                null);
            ilg.Ldarg(0);
            ilg.Call(XmlSerializationReader_ReadNull);
            ilg.If();
            {
                ilg.Ldloc(oLoc);
                ilg.Stloc(ilg.ReturnLocal);
                ilg.Br(ilg.ReturnLabel);
            }
            ilg.EndIf();

            ElementAccessor element = new ElementAccessor();
            element.Mapping = nullableMapping.BaseMapping;
            element.Any = false;
            element.IsNullable = nullableMapping.BaseMapping.TypeDesc.IsNullable;

            WriteElement("o", null, null, element, null, null, false, false, -1, -1);
            ilg.Ldloc(oLoc);
            ilg.Stloc(ilg.ReturnLocal);
            ilg.Br(ilg.ReturnLabel);

            ilg.MarkLabel(ilg.ReturnLabel);
            ilg.Ldloc(ilg.ReturnLocal);
            ilg.EndMethod();
        }

        void WriteEnumMethod(EnumMapping mapping) {
            MethodBuilder get_TableName = null;
            if (mapping.IsFlags)
                WriteHashtable(mapping, mapping.TypeDesc.Name, out get_TableName);

            string methodName = (string)MethodNames[mapping];
            string fullTypeName = mapping.TypeDesc.CSharpName;
            List<Type> argTypes = new List<Type>();
            List<string> argNames = new List<string>();
            Type returnType;
            Type underlyingType;

            returnType = mapping.TypeDesc.Type;
            underlyingType = Enum.GetUnderlyingType(returnType);
            argTypes.Add(typeof(string));
            argNames.Add("s");
            ilg = new CodeGenerator(this.typeBuilder);
            ilg.BeginMethod(
                returnType,
                GetMethodBuilder(methodName),
                argTypes.ToArray(),
                argNames.ToArray(),
                CodeGenerator.PrivateMethodAttributes);

            ConstantMapping[] constants = mapping.Constants;
            if (mapping.IsFlags) {
                {
                    MethodInfo XmlSerializationReader_ToEnum = typeof(XmlSerializationReader).GetMethod(
                        "ToEnum",
                        CodeGenerator.StaticBindingFlags,
                        null,
                        new Type[] { typeof(String), typeof(Hashtable), typeof(String) },
                        null
                        );
                    ilg.Ldarg("s");
                    ilg.Ldarg(0);
                    Debug.Assert(get_TableName != null);
                    ilg.Call(get_TableName);
                    ilg.Ldstr(fullTypeName);
                    ilg.Call(XmlSerializationReader_ToEnum);
                    // XmlSerializationReader_ToEnum return long!
                    if (underlyingType != typeof(long)) {
                        ilg.ConvertValue(typeof(long), underlyingType);
                    }
                    ilg.Stloc(ilg.ReturnLocal);
                    ilg.Br(ilg.ReturnLabel);
                }
            }
            else {
                List<Label> caseLabels = new List<Label>();
                List<object> retValues = new List<object>();
                Label defaultLabel = ilg.DefineLabel();
                Label endSwitchLabel = ilg.DefineLabel();
                // This local is necessary; otherwise, it becomes if/else
                LocalBuilder localTmp = ilg.GetTempLocal(typeof(string));
                ilg.Ldarg("s");
                ilg.Stloc(localTmp);
                ilg.Ldloc(localTmp);
                ilg.Brfalse(defaultLabel);
                Hashtable cases = new Hashtable();
                for (int i = 0; i < constants.Length; i++) {
                    ConstantMapping c = constants[i];

                    CodeIdentifier.CheckValidIdentifier(c.Name);
                    if (cases[c.XmlName] == null) {
                        cases[c.XmlName] = c.XmlName;
                        Label caseLabel = ilg.DefineLabel();
                        ilg.Ldloc(localTmp);
                        ilg.Ldstr(c.XmlName);
                        MethodInfo String_op_Equality = typeof(string).GetMethod(
                            "op_Equality",
                            CodeGenerator.StaticBindingFlags,
                            null,
                            new Type[] { typeof(string), typeof(string) },
                            null
                            );
                        ilg.Call(String_op_Equality);
                        ilg.Brtrue(caseLabel);
                        caseLabels.Add(caseLabel);
                        retValues.Add(Enum.ToObject(mapping.TypeDesc.Type, c.Value));
                    }
                }

                ilg.Br(defaultLabel);
                // Case bodies
                for (int i = 0; i < caseLabels.Count; i++) {
                    ilg.MarkLabel(caseLabels[i]);
                    ilg.Ldc(retValues[i]);
                    ilg.Stloc(ilg.ReturnLocal);
                    ilg.Br(ilg.ReturnLabel);
                }
                MethodInfo XmlSerializationReader_CreateUnknownConstantException = typeof(XmlSerializationReader).GetMethod(
                    "CreateUnknownConstantException",
                    CodeGenerator.InstanceBindingFlags,
                    null,
                    new Type[] { typeof(string), typeof(Type) },
                    null
                    );
                // Default body
                ilg.MarkLabel(defaultLabel);
//.........这里部分代码省略.........

        private void WriteEnumMethod(EnumMapping mapping)
        {
            string methodName = (string)MethodNames[mapping];
            List<Type> argTypes = new List<Type>();
            List<string> argNames = new List<string>();
            argTypes.Add(mapping.TypeDesc.Type);
            argNames.Add("v");
            ilg = new CodeGenerator(this.typeBuilder);
            ilg.BeginMethod(
                typeof(string),
                GetMethodBuilder(methodName),
                argTypes.ToArray(),
                argNames.ToArray(),
                CodeGenerator.PrivateMethodAttributes);
            LocalBuilder sLoc = ilg.DeclareLocal(typeof(string), "s");
            ilg.Load(null);
            ilg.Stloc(sLoc);
            ConstantMapping[] constants = mapping.Constants;

            if (constants.Length > 0)
            {
                InternalHashtable values = new InternalHashtable();
                List<Label> caseLabels = new List<Label>();
                List<string> retValues = new List<string>();
                Label defaultLabel = ilg.DefineLabel();
                Label endSwitchLabel = ilg.DefineLabel();
                // This local is necessary; otherwise, it becomes if/else
                LocalBuilder localTmp = ilg.DeclareLocal(mapping.TypeDesc.Type, "localTmp");
                ilg.Ldarg("v");
                ilg.Stloc(localTmp);
                for (int i = 0; i < constants.Length; i++)
                {
                    ConstantMapping c = constants[i];
                    if (values[c.Value] == null)
                    {
                        Label caseLabel = ilg.DefineLabel();
                        ilg.Ldloc(localTmp);
                        ilg.Ldc(Enum.ToObject(mapping.TypeDesc.Type, c.Value));
                        ilg.Beq(caseLabel);
                        caseLabels.Add(caseLabel);
                        retValues.Add(GetCSharpString(c.XmlName));
                        values.Add(c.Value, c.Value);
                    }
                }


                if (mapping.IsFlags)
                {
                    ilg.Br(defaultLabel);
                    for (int i = 0; i < caseLabels.Count; i++)
                    {
                        ilg.MarkLabel(caseLabels[i]);
                        ilg.Ldc(retValues[i]);
                        ilg.Stloc(sLoc);
                        ilg.Br(endSwitchLabel);
                    }
                    ilg.MarkLabel(defaultLabel);
                    RaCodeGen.ILGenForEnumLongValue(ilg, "v");
                    LocalBuilder strArray = ilg.DeclareLocal(typeof(String[]), "strArray");
                    ilg.NewArray(typeof(String), constants.Length);
                    ilg.Stloc(strArray);
                    for (int i = 0; i < constants.Length; i++)
                    {
                        ConstantMapping c = constants[i];
                        ilg.Ldloc(strArray);
                        ilg.Ldc(i);
                        ilg.Ldstr(GetCSharpString(c.XmlName));
                        ilg.Stelem(typeof(String));
                    }
                    ilg.Ldloc(strArray);
                    LocalBuilder longArray = ilg.DeclareLocal(typeof(long[]), "longArray");
                    ilg.NewArray(typeof(long), constants.Length);
                    ilg.Stloc(longArray);

                    for (int i = 0; i < constants.Length; i++)
                    {
                        ConstantMapping c = constants[i];
                        ilg.Ldloc(longArray);
                        ilg.Ldc(i);
                        ilg.Ldc(c.Value);
                        ilg.Stelem(typeof(long));
                    }
                    ilg.Ldloc(longArray);
                    ilg.Ldstr(GetCSharpString(mapping.TypeDesc.FullName));
                    MethodInfo XmlSerializationWriter_FromEnum = typeof(XmlSerializationWriter).GetMethod(
                        "FromEnum",
                        CodeGenerator.StaticBindingFlags,
                        new Type[] { typeof(Int64), typeof(String[]), typeof(Int64[]), typeof(String) }
                        );
                    ilg.Call(XmlSerializationWriter_FromEnum);
                    ilg.Stloc(sLoc);
                    ilg.Br(endSwitchLabel);
                }
                else
                {
                    ilg.Br(defaultLabel);
                    // Case bodies
                    for (int i = 0; i < caseLabels.Count; i++)
                    {
                        ilg.MarkLabel(caseLabels[i]);
//.........这里部分代码省略.........

        private string GenerateMembersElement(XmlMembersMapping xmlMembersMapping)
        {
            ElementAccessor element = xmlMembersMapping.Accessor;
            MembersMapping mapping = (MembersMapping)element.Mapping;
            bool hasWrapperElement = mapping.HasWrapperElement;
            bool writeAccessors = mapping.WriteAccessors;
            string methodName = NextMethodName(element.Name);
            ilg = new CodeGenerator(this.typeBuilder);
            ilg.BeginMethod(
                typeof(void),
                methodName,
                new Type[] { typeof(object[]) },
                new string[] { "p" },
                CodeGenerator.PublicMethodAttributes
                );

            MethodInfo XmlSerializationWriter_WriteStartDocument = typeof(XmlSerializationWriter).GetMethod(
                "WriteStartDocument",
                CodeGenerator.InstanceBindingFlags,
                Array.Empty<Type>()
                );
            ilg.Ldarg(0);
            ilg.Call(XmlSerializationWriter_WriteStartDocument);

            MethodInfo XmlSerializationWriter_TopLevelElement = typeof(XmlSerializationWriter).GetMethod(
                "TopLevelElement",
                CodeGenerator.InstanceBindingFlags,
                Array.Empty<Type>()
                );
            ilg.Ldarg(0);
            ilg.Call(XmlSerializationWriter_TopLevelElement);

            // in the top-level method add check for the parameters length, 
            // because visual basic does not have a concept of an <out> parameter it uses <ByRef> instead
            // so sometime we think that we have more parameters then supplied
            LocalBuilder pLengthLoc = ilg.DeclareLocal(typeof(int), "pLength");
            ilg.Ldarg("p");
            ilg.Ldlen();
            ilg.Stloc(pLengthLoc);

            if (hasWrapperElement)
            {
                WriteStartElement(element.Name, (element.Form == XmlSchemaForm.Qualified ? element.Namespace : ""), false);

                int xmlnsMember = FindXmlnsIndex(mapping.Members);
                if (xmlnsMember >= 0)
                {
                    MemberMapping member = mapping.Members[xmlnsMember];
                    string source = "((" + typeof(XmlSerializerNamespaces).FullName + ")p[" + xmlnsMember.ToString(CultureInfo.InvariantCulture) + "])";

                    ilg.Ldloc(pLengthLoc);
                    ilg.Ldc(xmlnsMember);
                    ilg.If(Cmp.GreaterThan);
                    WriteNamespaces(source);
                    ilg.EndIf();
                }

                for (int i = 0; i < mapping.Members.Length; i++)
                {
                    MemberMapping member = mapping.Members[i];

                    if (member.Attribute != null && !member.Ignore)
                    {
                        SourceInfo source = new SourceInfo("p[" + i.ToString(CultureInfo.InvariantCulture) + "]", null, null, pLengthLoc.LocalType.GetElementType(), ilg);

                        SourceInfo specifiedSource = null;
                        int specifiedPosition = 0;
                        if (member.CheckSpecified != SpecifiedAccessor.None)
                        {
                            string memberNameSpecified = member.Name + "Specified";
                            for (int j = 0; j < mapping.Members.Length; j++)
                            {
                                if (mapping.Members[j].Name == memberNameSpecified)
                                {
                                    specifiedSource = new SourceInfo("((bool)p[" + j.ToString(CultureInfo.InvariantCulture) + "])", null, null, typeof(bool), ilg);
                                    specifiedPosition = j;
                                    break;
                                }
                            }
                        }

                        ilg.Ldloc(pLengthLoc);
                        ilg.Ldc(i);
                        ilg.If(Cmp.GreaterThan);

                        if (specifiedSource != null)
                        {
                            Label labelTrue = ilg.DefineLabel();
                            Label labelEnd = ilg.DefineLabel();
                            ilg.Ldloc(pLengthLoc);
                            ilg.Ldc(specifiedPosition);
                            ilg.Ble(labelTrue);
                            specifiedSource.Load(typeof(bool));
                            ilg.Br_S(labelEnd);
                            ilg.MarkLabel(labelTrue);
                            ilg.Ldc(true);
                            ilg.MarkLabel(labelEnd);
                            ilg.If();
                        }

//.........这里部分代码省略.........

        internal void ILGenForCreateInstance(CodeGenerator ilg, Type type, Type cast, bool nonPublic)
        {
            // Special case DBNull
            if (type == Globals.TypeOfDBNull)
            {
                FieldInfo DBNull_Value = Globals.TypeOfDBNull.GetField("Value", CodeGenerator.StaticBindingFlags);
                ilg.LoadMember(DBNull_Value);
                return;
            }

            // Special case XElement
            // codegen the same as 'internal XElement : this("default") { }'
            if (type.FullName == "System.Xml.Linq.XElement")
            {
                Type xName = type.GetTypeInfo().Assembly.GetType("System.Xml.Linq.XName");
                if (xName != null)
                {
                    MethodInfo XName_op_Implicit = xName.GetMethod(
                        "op_Implicit",
                        CodeGenerator.StaticBindingFlags,
                        new Type[] { typeof(String) }
                        );
                    ConstructorInfo XElement_ctor = type.GetConstructor(
                        CodeGenerator.InstanceBindingFlags,
                        new Type[] { xName }
                        );
                    if (XName_op_Implicit != null && XElement_ctor != null)
                    {
                        ilg.Ldstr("default");
                        ilg.Call(XName_op_Implicit);
                        ilg.New(XElement_ctor);
                        return;
                    }
                }
            }

            Label labelReturn = ilg.DefineLabel();
            Label labelEndIf = ilg.DefineLabel();

            // TypeInfo typeInfo = type.GetTypeInfo();
            // typeInfo not declared explicitly
            ilg.Ldc(type);
            MethodInfo getTypeInfoMehod = typeof(IntrospectionExtensions).GetMethod(
                  "GetTypeInfo",
                  CodeGenerator.StaticBindingFlags,
                  new[] { typeof(Type) }
                  );
            ilg.Call(getTypeInfoMehod);

            // IEnumerator<ConstructorInfo> e = typeInfo.DeclaredConstructors.GetEnumerator();
            LocalBuilder enumerator = ilg.DeclareLocal(typeof(IEnumerator<>).MakeGenericType(typeof(ConstructorInfo)), "e");
            MethodInfo getDeclaredConstructors = typeof(TypeInfo).GetMethod("get_DeclaredConstructors");
            MethodInfo getEnumerator = typeof(IEnumerable<>).MakeGenericType(typeof(ConstructorInfo)).GetMethod("GetEnumerator");
            ilg.Call(getDeclaredConstructors);
            ilg.Call(getEnumerator);
            ilg.Stloc(enumerator);

            ilg.WhileBegin();
            // ConstructorInfo constructorInfo = e.Current();
            MethodInfo enumeratorCurrent = typeof(IEnumerator).GetMethod("get_Current");
            ilg.Ldloc(enumerator);
            ilg.Call(enumeratorCurrent);
            LocalBuilder constructorInfo = ilg.DeclareLocal(typeof(ConstructorInfo), "constructorInfo");
            ilg.Stloc(constructorInfo);

            // if (!constructorInfo.IsStatic && constructorInfo.GetParameters.Length() == 0)
            ilg.Ldloc(constructorInfo);
            MethodInfo constructorIsStatic = typeof(ConstructorInfo).GetMethod("get_IsStatic");
            ilg.Call(constructorIsStatic);
            ilg.Brtrue(labelEndIf);
            ilg.Ldloc(constructorInfo);
            MethodInfo constructorGetParameters = typeof(ConstructorInfo).GetMethod("GetParameters");
            ilg.Call(constructorGetParameters);
            ilg.Ldlen();
            ilg.Ldc(0);
            ilg.Cne();
            ilg.Brtrue(labelEndIf);

            // constructorInfo.Invoke(null);
            MethodInfo constructorInvoke = typeof(ConstructorInfo).GetMethod("Invoke", new Type[] { typeof(object[]) });
            ilg.Ldloc(constructorInfo);
            ilg.Load(null);
            ilg.Call(constructorInvoke);
            ilg.Br(labelReturn);

            ilg.MarkLabel(labelEndIf);
            ilg.WhileBeginCondition(); // while (e.MoveNext())
            MethodInfo IEnumeratorMoveNext = typeof(IEnumerator).GetMethod(
                "MoveNext",
                CodeGenerator.InstanceBindingFlags,
                Array.Empty<Type>());
            ilg.Ldloc(enumerator);
            ilg.Call(IEnumeratorMoveNext);
            ilg.WhileEndCondition();
            ilg.WhileEnd();

            MethodInfo Activator_CreateInstance = typeof(Activator).GetMethod(
                  "CreateInstance",
                  CodeGenerator.StaticBindingFlags,
                  new Type[] { typeof(Type) }
//.........这里部分代码省略.........