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Trying to set up a CompareLists method with an overridden Equals/Gethash code methods

I'm trying to set up a way to compare some nested lists with objects that I'm importing from MongoDB. I have already set up the lists object:
public class SecurityGroup
{
public ObjectId Id { get; set; }
public string GroupID { get; set; }
public string GroupName{ get; set; }
public List<IpPermission> IpPermissions { get; set; }
public override string ToString()
{
return string.Format("groupid : {0}, groupname : {1} ", GroupID, GroupName );
}
With in that class I also have an overridden Equals method in place.
public override bool Equals(object obj)
{
SecurityGroup secGroup = obj as SecurityGroup;
if (secGroup == null)
{
return false;
}
if (!string.Equals(GroupID, secGroup.GroupID, StringComparison.OrdinalIgnoreCase))
{
return false;
}
if (!string.Equals(GroupName,secGroup.GroupName, StringComparison.OrdinalIgnoreCase))
{
return false;
}
I'm not sure if I need to post the class used for the nested loop but there's an IEquatable interface and the entireity of this class is EXACTLY like the SecurityGroup class I just posted.
//Compare IpPermissions
var diff1 = IpPermissions.Except(secGroup.IpPermissions);
var diff2 = secGroup.IpPermissions.Except(IpPermissions);
if (diff1.Any() || diff2.Any())
{
return false;
}
return true;
}
Now here's the Hashcode method that I set up:
public override int GetHashCode()
{
unchecked
{
const int HashingBase = (int)2166136261;
const int HashingMultiplier = 16777619;
int hash = HashingBase;
hash = (hash * HashingMultiplier) ^ (!Object.ReferenceEquals(null, IpPort) ? IpPort.GetHashCode() : 0);
hash = (hash * HashingMultiplier) ^ (!Object.ReferenceEquals(null, IpProtocol) ? IpProtocol.GetHashCode() : 0);
hash = (hash * HashingMultiplier) ^ (!Object.ReferenceEquals(null, IpRanges) ? IpRanges.GetHashCode() : 0);
return hash;
}
}
}
}
That essentially conludes the code I have in place to set up the framework for my comparesList method. Now here's where I'm having issues. I'm trying to set up the compare lists method and it's just giving me underscored red lines on the 'public static' part. The thing I can't figure out is the error it's giving me for the 'foreach' statements. It's saying, "Cannot convert element type 'AwsInstanceProfile1.Entity.SecurityGroup' to iterator type 'Amazon.EC2.Model.SecurityGroup'" Which is really weird because I should in theory have the framework set up to allow the lists into these objects. Here's the rest of the method:
public static bool CompareLists(List<Entity.SecurityGroup> list1, List<Entity.SecurityGroup> list2) =>
{
if (list1 == null || list2 == null)
return list1 == list2;
Dictionary<SecurityGroup, int> hash = new Dictionary<SecurityGroup, int>();
foreach (SecurityGroup secGroup in list1)
{
if (hash.ContainsKey(secGroup))
{
hash[secGroup]++;
}
else
{
hash.Add(secGroup, 1);
}
}
foreach (SecurityGroup secGroup in list2)
{
if (!hash.ContainsKey(secGroup) || hash[secGroup] == 0)
{
return false;
}
hash[secGroup]--;
}
return true;
}

How to check equality for a custom class array in C#?

I have a custom class named as City and this class has an Equals method. The SequenceEqual method works good when comparing arrays with assigned variables. The problem occurs when comparing two arrays that contains the elements formatted new City(). It results as false.
City class:
interface IGene : IEquatable<IGene>
{
string Name { get; set; }
int Index { get; set; }
}
class City : IGene
{
string name;
int index;
public City(string name, int index)
{
this.name = name;
this.index = index;
}
public string Name
{
get
{
return name;
}
set
{
name = value;
}
}
public int Index
{
get
{
return index;
}
set
{
index = value;
}
}
public bool Equals(IGene other)
{
if (other == null && this == null)
return true;
if((other is City))
{
City c = other as City;
return c.Name == this.Name && c.Index == this.Index;
}
return false;
}
}
In the Test method below, the first comparing result arrayCompare1 is true and the second result arrayCompare2 is false. Both compare result must be true but there is an anormal stuation. How can I fix this problem?
Test code:
public void Test()
{
City c1 = new City("A", 1);
City c2 = new City("B", 2);
City[] arr1 = new City[] { c1, c2 };
City[] arr2 = new City[] { c1, c2 };
City[] arr3 = new City[] { new City("A", 1), new City("B", 2) };
City[] arr4 = new City[] { new City("A", 1), new City("B", 2) };
bool arrayCompare1 = arr1.SequenceEqual(arr2);
bool arrayCompare2 = arr3.SequenceEqual(arr4);
MessageBox.Show(arrayCompare1 + " " + arrayCompare2);
}

You need to override the Object.Equals somehow like this:
public override bool Equals(object other)
{
if (other is IGene)
return Equals((IGene)other);
return base.Equals(other);
}

You need to override bool Equals(object obj). Simplest addition to your code:
public override bool Equals(object obj)
{
return Equals(obj as IGene);
}

cast datasource to object

i have class
public class CLASS_K
{
public static List<AA> simpleList = new List<AA>()
{
new AA(){NNN = "o1", NNN2 = "o1a"},
new AA(){NNN = "o2", NNN2 = "o2a"}
};
public class AA
{
public string NNN { get; set; }
public string NNN2 { get; set; }
}
}
and I set binding for label :
label1.DataBindings.Add("text", CLASS_K.simpleList[1], "NNN");
How cast dataSource from label to class AA ?
My wrong idea:
BindingSource binding = (BindingSource)label1.DataBindings[0].DataSource;
CLASS_K.AA b = (CLASS_K.AA) binding.DataSource;

DataSource contains object of type CLASS_K.AA, so try this:
if (label1.DataBindings.Count != 0)
{
var b = label1.DataBindings[0].DataSource as CLASS_K.AA;
if (b != null)
{
// do something...
}
}

Comparing two objects and returning the differences

I have to run comparisons between thousands of pairs of objects, and then perform actions depending on the differences.
Is there an "accepted" way of doing this?
class ObjectA
{
public string FieldA { get; set; }
public string FieldB { get; set; }
public string FieldC { get; set; }
}
class ObjectB
{
public string FieldA { get; set; }
public string FieldB { get; set; }
public string FieldC { get; set; }
public bool Equals(ObjectA obj)
{
if ((object)obj == null) return false;
if (this.FieldA != obj.FieldA) return false;
if (this.FieldB != obj.FieldB) return false;
if (this.FieldC != obj.FieldC) return false;
return true;
}
}
void test()
{
ObjectA a = new ObjectA();
ObjectB b = new ObjectB();
if (b.Equals(a))
{
Console.WriteLine("Same!!");
}
}
That does a fairly simple test to determine if b=a, but I also want to know what is different between them.
Should I add a differences() method that returns a list of properties? That seems a bit not.net though, as then I'll be bandying about strings.
public List<string> Differences(ObjectA obj)
{
List<string> differences = new List<string>();
if ((object)obj == null)
{
differences.Add("null");
}
else
{
if (this.FieldA != obj.FieldA) differences.Add("FieldA");
if (this.FieldB != obj.FieldB) differences.Add("FieldB");
if (this.FieldC != obj.FieldC) differences.Add("FieldC");
}
return differences;
}
Also that seems much slower than the first, as I would be creating all those List<string>, and not short-cutting the comparisons. Or is that just the price I pay for having the extra information?

Maybe you should try this:
http://comparenetobjects.codeplex.com/
All credit to the author...
Edit: Since codeplex is shutting down, the github url : https://github.com/GregFinzer/Compare-Net-Objects

There is nothing built in that will allow you to represent partial objects (i.e the differences).
Your approach seems reasonable for what you are trying to achieve.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
class ObjectA
{
public string PropertyA { get; set; }
public string PropertyB { get; set; }
public string PropertyC { get; set; }
public DateTime PropertyD { get; set; }
public string FieldA;
public DateTime FieldB;
}
class ObjectB
{
public string PropertyA { get; set; }
public string PropertyB { get; set; }
public string PropertyC { get; set; }
public DateTime PropertyD { get; set; }
public string FieldA;
public DateTime FieldB;
}
class Program
{
static void Main(string[] args)
{
// create two objects with same properties
ObjectA a = new ObjectA() { PropertyA = "test", PropertyB = "test2", PropertyC = "test3" };
ObjectB b = new ObjectB() { PropertyA = "test", PropertyB = "test2", PropertyC = "test3" };
// add fields to those objects
a.FieldA = "hello";
b.FieldA = "Something differnt";
if (a.ComparePropertiesTo(b))
{
Console.WriteLine("objects have the same properties");
}
else
{
Console.WriteLine("objects have diferent properties!");
}
if (a.CompareFieldsTo(b))
{
Console.WriteLine("objects have the same Fields");
}
else
{
Console.WriteLine("objects have diferent Fields!");
}
Console.Read();
}
}
public static class Utilities
{
public static bool ComparePropertiesTo(this Object a, Object b)
{
System.Reflection.PropertyInfo[] properties = a.GetType().GetProperties(); // get all the properties of object a
foreach (var property in properties)
{
var propertyName = property.Name;
var aValue = a.GetType().GetProperty(propertyName).GetValue(a, null);
object bValue;
try // try to get the same property from object b. maybe that property does
// not exist!
{
bValue = b.GetType().GetProperty(propertyName).GetValue(b, null);
}
catch
{
return false;
}
if (aValue == null && bValue == null)
continue;
if (aValue == null && bValue != null)
return false;
if (aValue != null && bValue == null)
return false;
// if properties do not match return false
if (aValue.GetHashCode() != bValue.GetHashCode())
{
return false;
}
}
return true;
}
public static bool CompareFieldsTo(this Object a, Object b)
{
System.Reflection.FieldInfo[] fields = a.GetType().GetFields(); // get all the properties of object a
foreach (var field in fields)
{
var fieldName = field.Name;
var aValue = a.GetType().GetField(fieldName).GetValue(a);
object bValue;
try // try to get the same property from object b. maybe that property does
// not exist!
{
bValue = b.GetType().GetField(fieldName).GetValue(b);
}
catch
{
return false;
}
if (aValue == null && bValue == null)
continue;
if (aValue == null && bValue != null)
return false;
if (aValue != null && bValue == null)
return false;
// if properties do not match return false
if (aValue.GetHashCode() != bValue.GetHashCode())
{
return false;
}
}
return true;
}
}

As long as the names of the properties are equal, you can do this using the property map of each object and linq. I've done this in the past, but I don't have the code in front of me at the moment, sorry.

Here's an example I used for unit testing two instances of the same object type. I was testing to ensure that the properties that were serialized to file and populated in a new instance of the same object type were the same. Note that this is using System.Reflection and that you are comparing instances of the same type.
//Assume yourobjectA and yourobjectB have already been instantiated and populated.
//loop throught he properties and compare
//they should all be set the same as the previous instance
PropertyInfo[] propertiesA = yourobjectA.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);
PropertyInfo[] propertiesB = yourobjectB.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);
int count = oldProperties.Length;
for (int i = 0; i < count; i++)
{
if ((propertiesA [i].CanRead) && (propertiesB [i].CanRead))
{
if (propertiesA [i].PropertyType == typeof(String))
{
object oldStringValue = (string)propertiesA[i].GetValue(yourobjectA, null);
object newStringValue = (string)propertiesB[i].GetValue(yourobjectB., null);
if(oldStringValue != newStringValue )
{
//Do something
}
}
if (propertiesA [i].PropertyType == typeof(Boolean))
{
object oldBoolValue = (bool)propertiesA [i].GetValue(yourobjectA, null);
object newBoolValue = (bool)propertiesB [i].GetValue(yourobjectB., null);
if(oldBoolValue != newBoolValue)
{
//Do something
}
}
}
}

MSUnit: Assert.AreEqual fails trees

I have to test the equality of trees. In other other words objects which contains List<T> with childs and the childs also contains List<T> with childs and so on.
I've found that you can test List with CollectionAssert, however it does not work that well with composites.
Any suggestions? MSUnit is my test library.
Example
IReagentComposed bronzeBarParsed = (from n in composedCrafts where n.ItemId == 2841 select n).Single();
IReagentComposed bronzeBar = new Craft()
{
ItemId = 2841,
Profession = Profession.Mining,
Quantity = 0,
QuantityCrafted = 0,
Skill = 50,
Reagents = new List()
{
new Craft()
{
ItemId = 2840,
Quantity = 0,
Skill = 1,
Profession = Profession.Mining,
Reagents = new List()
{
new Reagent()
{
ItemId = 2770,
Quantity = 1
}
}
},
new Craft()
{
ItemId = 3576,
Quantity = 0,
Skill = 50,
Profession = Profession.Mining,
Reagents = new List()
{
new Reagent()
{
ItemId = 2771,
Quantity = 1
}
}
}
}
};
Assert.AreEqual(bronzeBar, bronzeBarParsed);
Craft and Reagent
public class Craft : IReagentComposed
{
public int QuantityCrafted { get; set; }
public int Quantity { get; set;}
public int ItemId { get; set; }
public int Skill { get; set; }
public Profession Profession { get; set; }
public IEnumerable Reagents { get; set; }
public override bool Equals(object other)
{
if (other == null || GetType() != other.GetType()) return false;
IReagentComposed o = other as IReagentComposed;
return o != null && this.Quantity == o.Quantity &&
this.ItemId == o.ItemId &&
this.Profession == o.Profession &&
this.Reagents == o.Reagents && //also tried Equals
this.Skill == o.Skill;
}
public override int GetHashCode()
{
return 0;
}
}
public class Reagent : IReagent
{
public int ItemId { get; set; }
public int Quantity { get; set; }
public override bool Equals(object other)
{
if (other == null || GetType() != other.GetType()) return false;
IReagent o = other as IReagent;
return o != null && o.ItemId == this.ItemId && o.Quantity == this.Quantity;
}
public override int GetHashCode()
{
return 0;
}
}

return o != null && this.Quantity == o.Quantity &&
this.ItemId == o.ItemId &&
this.Profession == o.Profession &&
this.Reagents == o.Reagents && //also tried Equals
this.Skill == o.Skill;
The Reagents are unlikely to match, they are distinct List objects. List<> doesn't override Equals although it isn't that clear what actual type you use. Write a little helper function that takes two lists of reagents and checks for equality. You'd typically start at comparing List<>.Count and then work down the elements one by one.

Added a extension method for IEnumberable<T>:
public static class IEnumberableExtensions
{
public static bool AreEnumerablesEqual<T>(this IEnumerable<T> x, IEnumerable<T> y)
{
if (x.Count() != y.Count()) return false;
bool equals = false;
foreach (var a in x)
{
foreach (var b in y)
{
if (a.Equals(b))
{
equals = true;
break;
}
}
if (!equals)
{
return false;
}
equals = false;
}
return true;
}
}