使用ef，有时候会遇到，要对一个对象进行拷贝复制，可是一般的方法，拷贝后会提示此对象的实例在上下文的 entitystate已经存在，就需要用一种拷贝。
简单的拷贝只拷贝了值类型，对引用类型的拷贝需要使用递归，依次循环到底。
public object Copy(object obj) { Object targetDeepCopyObj; try { Type targetType = obj.GetType(); //值类型 if (targetType.IsValueType == true) { targetDeepCopyObj = obj; } //引用类型 else { targetDeepCopyObj = System.Activator.CreateInstance(targetType); //创建引用对象 System.Reflection.MemberInfo[] memberCollection = obj.GetType().GetMembers(); foreach (System.Reflection.MemberInfo member in memberCollection) { if (member.MemberType == System.Reflection.MemberTypes.Field) { System.Reflection.FieldInfo field = (System.Reflection.FieldInfo)member; Object fieldValue = field.GetValue(obj); if (fieldValue is ICloneable) { field.SetValue(targetDeepCopyObj, (fieldValue as ICloneable).Clone()); } else { field.SetValue(targetDeepCopyObj, Copy(fieldValue)); } } else if (member.MemberType == System.Reflection.MemberTypes.Property) { System.Reflection.PropertyInfo myProperty = (System.Reflection.PropertyInfo)member; MethodInfo info = myProperty.GetSetMethod(false); if (info != null) { object propertyValue = myProperty.GetValue(obj, null); if (propertyValue is ICloneable) { myProperty.SetValue(targetDeepCopyObj, (propertyValue as ICloneable).Clone(), null); } else { myProperty.SetValue(targetDeepCopyObj, Copy(propertyValue), null); } } } } } return targetDeepCopyObj; } catch (Exception e) { } return null; }
