如何通过反射在单个调用中获取字段和属性？

Question

如果在某处覆盖,我道歉.我在发帖前做过研究!

好吧,所以问题...我正在使用GetType().GetProperties,但它没有返回简单的实例字段,它们没有get/set ...所以我使用了.GetFields,找到它们,但我希望得到一个简单的单个对象来获取/设置一个值而不在字段和属性之间翻转......这可能吗？

我目前的代码适用于PropertyInfo,它工作得很好,但那不是我认为的字段吗？

[编辑] 这是我提出的解决方案,这是很好的.感谢大家....

    // some logic borrowed from James Newton-King, http://www.newtonsoft.com
    public static void SetValue(this MemberInfo member, object property, object value)
    {
        if (member.MemberType == MemberTypes.Property)
            ((PropertyInfo)member).SetValue(property, value, null);
        else if (member.MemberType == MemberTypes.Field)
            ((FieldInfo)member).SetValue(property, value);
        else
            throw new Exception("Property must be of type FieldInfo or PropertyInfo");
    }

    public static object GetValue(this MemberInfo member, object property)
    {
        if (member.MemberType == MemberTypes.Property)
            return ((PropertyInfo)member).GetValue(property, null);
        else if (member.MemberType == MemberTypes.Field)
            return ((FieldInfo)member).GetValue(property);
        else
            throw new Exception("Property must be of type FieldInfo or PropertyInfo");
    }

    public static Type GetType(this MemberInfo member)
    {
        switch (member.MemberType)
        {
            case MemberTypes.Field:
                return ((FieldInfo)member).FieldType;
            case MemberTypes.Property:
                return ((PropertyInfo)member).PropertyType;
            case MemberTypes.Event:
                return ((EventInfo)member).EventHandlerType;
            default:
                throw new ArgumentException("MemberInfo must be if type FieldInfo, PropertyInfo or EventInfo", "member");
        }
    }

Answer 1

怎么样:

const BindingFlags bindingFlags = BindingFlags.Public | BindingFlags.Instance;
MemberInfo[] members = type.GetFields(bindingFlags).Cast<MemberInfo>()
    .Concat(type.GetProperties(bindingFlags)).ToArray();

或者,像FastMember这样的库可以很好地使用字段或属性,无论成员类型如何,get/set都是相同的.

Answer 2

正如您似乎注意到的那样,GetProperties()和GetFields()的返回类型是不同的.您必须使用GetValue()和SetValue()定义接口,并使用扩展ParameterInfo和FieldInfo来实现此接口.这可能是一个包装器:

interface IGetSettable
{
    public void SetValue(
        Object obj,
        Object value,
        Object[] index);
    public Object GetValue(
        Object obj,
        Object[] index);
}

public class ParameterInfoGS : IGetSettable
{
    protected ParameterInfo pi;

    public ParameterInfoExtra(ParameterInfo _pi)
    {
        pi = _pi;
    }

    public void SetValue(
        Object obj,
        Object value,
        Object[] index) {pi.SetValue(obj, value, index);}
    public Object GetValue(
        Object obj,
        Object[] index) {return pi.GetValue(obj, index);}
}

public class FieldInfoGS : IGetSettable
{
    protected FieldInfo pi;

    public FieldInfoExtra(FieldInfo _pi)
    {
        pi = _pi;
    }

    public void SetValue(
        Object obj,
        Object value,
        Object[] index) {pi.SetValue(obj, value, index);}
    public Object GetValue(
        Object obj,
        Object[] index) {return pi.GetValue(obj, index);}
}

public static class AssemblyExtension
{
    public static IGetSettable[] GetParametersAndFields(this Type t)
    {
        List<IGetSettable> retList = new List<IGetSettable>();

        foreach(ParameterInfo pi in t.GetParameters())
            retList.Add(new ParameterInfoExtra(pi));

        foreach(FieldInfo fi in t.GetFields())
            retList.Add(new FieldInfoExtra(fi));

        return retList.ToArray();
    }
}

这将允许您这样做GetType().GetParametersAndFields()(即使用标准反射类型).

Answer 3

有点晚了,但我想出了以下...... 1循环,就像一个魅力;-)

        MemberInfo[] memberInfos = dotNetType.GetMembers();
        ModelPropertySpec modelPropertySpec;
        foreach (MemberInfo memberInfo in memberInfos)
        {
            Type itemType = null;
            String memberName = memberInfo.Name;
            switch (memberInfo.MemberType)
            {
                case MemberTypes.Property:
                    itemType = dotNetType.GetProperty(memberName).PropertyType;
                    break;
                case MemberTypes.Field:
                    itemType = dotNetType.GetField(memberName).FieldType;
                    break;
            }

            if (itemType != null)
            {
                modelPropertySpec = ParsePropertyType(memberName, itemType);
                modelSpec.Properties.Add(modelPropertySpec.Name, modelPropertySpec);
            }
        }

Answer 4

要获得属性或字段,您可以说:

var q=
    from it in type.GetMembers(bindingAttr)
    where it is PropertyInfo||it is FieldInfo
    select it;

哪里bindingAttr可以

var bindingAttr=
        BindingFlags.NonPublic|
        BindingFlags.Public|
        BindingFlags.Instance;

BindingFlags.NonPublic如果您不想获得非公开会员,请删除.顺便说一句,查询不是单个调用而是单个语句.

要获取属性或字段的值而不自行转换它,请使用InvokeMember技巧:

static object GetValue<T>(
        T x, object target) where T:MemberInfo {
    var invokeAttr=(
            x is FieldInfo
                ?BindingFlags.GetField
                :x is PropertyInfo
                    ?BindingFlags.GetProperty
                    :BindingFlags.Default)|
            BindingFlags.NonPublic|
            BindingFlags.Public|
            BindingFlags.Instance;

    return target.GetType().InvokeMember(
        x.Name, invokeAttr, default(Binder), target, null);
}

同样,要设置值:

static void SetValue<T>(
        T x, object target, object value) where T:MemberInfo {
    var args=new object[] { value };
    var invokeAttr=(
            x is FieldInfo
                ?BindingFlags.SetField
                :x is PropertyInfo
                    ?BindingFlags.SetProperty
                    :BindingFlags.Default)|
            BindingFlags.NonPublic|
            BindingFlags.Public|
            BindingFlags.Instance;

    target.GetType().InvokeMember(
        x.Name, invokeAttr, default(Binder), target, args);
}

如果您传递的MemberInfo不是PropertyInfo或FieldInfo作为第一个参数,它将抛出,因为BindingFlags.Default没有指定您将要执行的操作.