我个人就使用这种方法

if (typeof(Foo).GetFields(BindingFlags.NonPublic | BindingFlags.Instance).Any(c => c.GetCustomAttributes(typeof(SomeAttribute), false).Any()))
{ 
    // do stuff
}

是的，但是你需要设置你的绑定标志来搜索私有字段(如果你在类实例之外寻找成员)。

你需要的绑定标志是:System.Reflection.BindingFlags.NonPublic

如果你的. net框架大于4.5。您可以使用GetRuntimeFields方法。

此方法返回在指定类型上定义的所有字段，包括继承的、非公共的、实例的和静态的字段。

https://learn.microsoft.com/en-us/dotnet/api/system.reflection.runtimereflectionextensions.getruntimefields?view=net-6.0

var foo = new Foo();
var fooFields = foo.GetType().GetRuntimeFields()

下面是一些简单的get和set私有字段和属性(带有setter的属性)的扩展方法:

使用的例子:

公共类Foo ｛ private int Bar = 5; ｝ var targetObject = new Foo(); var barValue = targetObject.GetMemberValue("Bar") targetObject。SetMemberValue("Bar"， 10);//设置Bar值为10

代码:

    /// <summary>
    /// Extensions methos for using reflection to get / set member values
    /// </summary>
    public static class ReflectionExtensions
    {
        /// <summary>
        /// Gets the public or private member using reflection.
        /// </summary>
        /// <param name="obj">The source target.</param>
        /// <param name="memberName">Name of the field or property.</param>
        /// <returns>the value of member</returns>
        public static object GetMemberValue(this object obj, string memberName)
        {
            var memInf = GetMemberInfo(obj, memberName);

            if (memInf == null)
                throw new System.Exception("memberName");

            if (memInf is System.Reflection.PropertyInfo)
                return memInf.As<System.Reflection.PropertyInfo>().GetValue(obj, null);

            if (memInf is System.Reflection.FieldInfo)
                return memInf.As<System.Reflection.FieldInfo>().GetValue(obj);

            throw new System.Exception();
        }

        /// <summary>
        /// Gets the public or private member using reflection.
        /// </summary>
        /// <param name="obj">The target object.</param>
        /// <param name="memberName">Name of the field or property.</param>
        /// <returns>Old Value</returns>
        public static object SetMemberValue(this object obj, string memberName, object newValue)
        {
            var memInf = GetMemberInfo(obj, memberName);


            if (memInf == null)
                throw new System.Exception("memberName");

            var oldValue = obj.GetMemberValue(memberName);

            if (memInf is System.Reflection.PropertyInfo)
                memInf.As<System.Reflection.PropertyInfo>().SetValue(obj, newValue, null);
            else if (memInf is System.Reflection.FieldInfo)
                memInf.As<System.Reflection.FieldInfo>().SetValue(obj, newValue);
            else
                throw new System.Exception();

            return oldValue;
        }

        /// <summary>
        /// Gets the member info
        /// </summary>
        /// <param name="obj">source object</param>
        /// <param name="memberName">name of member</param>
        /// <returns>instanse of MemberInfo corresponsing to member</returns>
        private static System.Reflection.MemberInfo GetMemberInfo(object obj, string memberName)
        {
            var prps = new System.Collections.Generic.List<System.Reflection.PropertyInfo>();

            prps.Add(obj.GetType().GetProperty(memberName,
                                               System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance |
                                               System.Reflection.BindingFlags.FlattenHierarchy));
            prps = System.Linq.Enumerable.ToList(System.Linq.Enumerable.Where( prps,i => !ReferenceEquals(i, null)));
            if (prps.Count != 0)
                return prps[0];

            var flds = new System.Collections.Generic.List<System.Reflection.FieldInfo>();

            flds.Add(obj.GetType().GetField(memberName,
                                            System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance |
                                            System.Reflection.BindingFlags.FlattenHierarchy));

            //to add more types of properties

            flds = System.Linq.Enumerable.ToList(System.Linq.Enumerable.Where(flds, i => !ReferenceEquals(i, null)));

            if (flds.Count != 0)
                return flds[0];

            return null;
        }

        [System.Diagnostics.DebuggerHidden]
        private static T As<T>(this object obj)
        {
            return (T)obj;
        }
    }

使用Reflection获取私有变量的值:

var _barVariable = typeof(Foo).GetField("_bar", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(objectForFooClass);

使用Reflection为私有变量设置值:

typeof(Foo).GetField("_bar", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(objectForFoocClass, "newValue");

其中objectForFooClass是类类型Foo的非空实例。

我在谷歌上搜索这个时遇到了这个，所以我意识到我在撞一个旧帖子。然而GetCustomAttributes需要两个参数。

typeof(Foo).GetFields(BindingFlags.NonPublic | BindingFlags.Instance)
.Where(x => x.GetCustomAttributes(typeof(SomeAttribute), false).Length > 0);

第二个参数指定是否希望搜索继承层次结构