如何使用方法调用生成已编译的lambda？

我在运行时为给定的成员生成编译的getter方法.现在,我的代码只是假设getter方法的结果是一个字符串(适用于测试).但是,我想用我编写的自定义转换器类来完成这项工作,请参阅下面的"ConverterBase"参考,我已经添加了.

我无法弄清楚如何将转换器类的调用添加到我的表达式树.

    public Func GetGetter(MemberInfo info)
    {
        Type t = null;
        if (info is PropertyInfo) 
        {
            t = ((PropertyInfo)info).PropertyType;
        }
        else if (info is FieldInfo)
        {
            t = ((FieldInfo)info).FieldType;
        }
        else
        {
            throw new Exception("Unknown member type");
        }

        //TODO, replace with ability to specify in custom attribute
        ConverterBase typeConverter = new ConverterBase();

        ParameterExpression target = Expression.Parameter(typeof(U), "target");
        MemberExpression memberAccess = Expression.MakeMemberAccess(target, info);

        //TODO here, make the expression call "typeConverter.FieldToString(fieldValue)"

        LambdaExpression getter = Expression.Lambda(memberAccess, target);

        return (Func)getter.Compile();
    }

    ConverterBase typeConverter = new ConverterBase();
    var target = Expression.Parameter(typeof(U), "target");
    var getter = Expression.MakeMemberAccess(target, info);
    var converter = Expression.Constant(typeConverter, typeof(ConverterBase));

    return Expression.Lambda>(
    Expression.Call(converter, typeof(ConverterBase).GetMethod("FieldToString"),
        getter), target).Compile();

    MethodInfo method = typeof(ConverterBase).GetMethod("FieldToString");
    return Expression.Lambda>(
        Expression.Call(converter, method,
            Expression.Convert(getter, method.GetParameters().Single().ParameterType)),
            target).Compile();