是否可以通过反思来设置私有财产？

我可以通过反思设置私人财产吗？

public abstract class Entity { private int _id; private DateTime? _createdOn; public virtual T Id { get { return _id; } private set { ChangePropertyAndNotify(ref _id, value, x => Id); } } public virtual DateTime? CreatedOn { get { return _createdOn; } private set { ChangePropertyAndNotify(ref _createdOn, value, x => CreatedOn); } } } 

我已经尝试了以下，它不起作用，其中t代表一种Entity ：

 var t = typeof(Entity); var mi = t.GetMethod("set_CreatedOn", BindingFlags.Instance | BindingFlags.NonPublic); 

我想我可以做到这一点，但我不能解决。

Answer 1

 t.GetProperty("CreatedOn") .SetValue(obj, new DateTime(2009, 10, 14), null); 

编辑：由于属性本身是公共的，你显然不需要使用BindingFlags.NonPublicfind它。 调用SetValue尽pipesetter具有较less的可访问性仍然是你所期望的。

Answer 2

是的：

  /// <summary> /// Returns a _private_ Property Value from a given Object. Uses Reflection. /// Throws a ArgumentOutOfRangeException if the Property is not found. /// </summary> /// <typeparam name="T">Type of the Property</typeparam> /// <param name="obj">Object from where the Property Value is returned</param> /// <param name="propName">Propertyname as string.</param> /// <returns>PropertyValue</returns> public static T GetPrivatePropertyValue<T>(this object obj, string propName) { if (obj == null) throw new ArgumentNullException("obj"); PropertyInfo pi = obj.GetType().GetProperty(propName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance); if (pi == null) throw new ArgumentOutOfRangeException("propName", string.Format("Property {0} was not found in Type {1}", propName, obj.GetType().FullName)); return (T)pi.GetValue(obj, null); } /// <summary> /// Returns a private Property Value from a given Object. Uses Reflection. /// Throws a ArgumentOutOfRangeException if the Property is not found. /// </summary> /// <typeparam name="T">Type of the Property</typeparam> /// <param name="obj">Object from where the Property Value is returned</param> /// <param name="propName">Propertyname as string.</param> /// <returns>PropertyValue</returns> public static T GetPrivateFieldValue<T>(this object obj, string propName) { if (obj == null) throw new ArgumentNullException("obj"); Type t = obj.GetType(); FieldInfo fi = null; while (fi == null && t != null) { fi = t.GetField(propName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance); t = t.BaseType; } if (fi == null) throw new ArgumentOutOfRangeException("propName", string.Format("Field {0} was not found in Type {1}", propName, obj.GetType().FullName)); return (T)fi.GetValue(obj); } /// <summary> /// Sets a _private_ Property Value from a given Object. Uses Reflection. /// Throws a ArgumentOutOfRangeException if the Property is not found. /// </summary> /// <typeparam name="T">Type of the Property</typeparam> /// <param name="obj">Object from where the Property Value is set</param> /// <param name="propName">Propertyname as string.</param> /// <param name="val">Value to set.</param> /// <returns>PropertyValue</returns> public static void SetPrivatePropertyValue<T>(this object obj, string propName, T val) { Type t = obj.GetType(); if (t.GetProperty(propName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance) == null) throw new ArgumentOutOfRangeException("propName", string.Format("Property {0} was not found in Type {1}", propName, obj.GetType().FullName)); t.InvokeMember(propName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.SetProperty | BindingFlags.Instance, null, obj, new object[] { val }); } /// <summary> /// Set a private Property Value on a given Object. Uses Reflection. /// </summary> /// <typeparam name="T">Type of the Property</typeparam> /// <param name="obj">Object from where the Property Value is returned</param> /// <param name="propName">Propertyname as string.</param> /// <param name="val">the value to set</param> /// <exception cref="ArgumentOutOfRangeException">if the Property is not found</exception> public static void SetPrivateFieldValue<T>(this object obj, string propName, T val) { if (obj == null) throw new ArgumentNullException("obj"); Type t = obj.GetType(); FieldInfo fi = null; while (fi == null && t != null) { fi = t.GetField(propName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance); t = t.BaseType; } if (fi == null) throw new ArgumentOutOfRangeException("propName", string.Format("Field {0} was not found in Type {1}", propName, obj.GetType().FullName)); fi.SetValue(obj, val); } 

Answer 3

你可以通过代码从派生types访问私有setter

 public static void SetProperty(object instance, string propertyName, object newValue) { Type type = instance.GetType(); PropertyInfo prop = type.BaseType.GetProperty(propertyName); prop.SetValue(instance, newValue, null); } 

Answer 4

这些都没有为我工作，我的财产名称是独特的，所以我只是用这个：

 public static void SetPrivatePropertyValue<T>(T obj, string propertyName, object newValue) { // add a check here that the object obj and propertyName string are not null foreach (FieldInfo fi in obj.GetType().GetFields(BindingFlags.Instance | BindingFlags.NonPublic)) { if (fi.Name.ToLower().Contains(propertyName.ToLower())) { fi.SetValue(obj, newValue); break; } } } 

Answer 5

  //mock class public class Person{ public string Name{get; internal set;} } // works for all types, update private field through reflection public static T ReviveType<T>(T t, string propertyName, object newValue){ // add a check here that the object t and propertyName string are not null PropertyInfo pi = t.GetType().GetProperty(propertyName, BindingFlags.Public | BindingFlags.Instance); pi.SetValue(t, newValue, null); return t; } // check the required function void Main() { var p = new Person(){Name="John"}; Console.WriteLine("Name: {0}",p.Name); //box the person to object, just to see that the method never care about what type you pass it object o = p; var updatedPerson = ReviveType<Object>(o, "Name", "Webber") as Person; //check if it updated person instance Console.WriteLine("Name: {0}",updatedPerson.Name); } // Console Result: ------------------- Name: John Name: Webber