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sorting a generic list from within a generic container class

I need to sort a list by any one of its properties, but i dont know which of these properties it will specifically be sorted on. The Main method below.
static void Main(string[] args)
{
Things<Something> something = new Things<Something>();
something.Add(new Something
{ Thing = "Apartment", Price = 1500000 });
something.Add(new Something
{ Thing = "Bed", Price = 10000 });
something.Add(new Something
{ Thing = "Lamp", Price = 600 });
something.Add(new Something
{ Thing = "Car", Price = 5000000 });
Console.WriteLine("\n\tStuff sorted by description");
something = something.SelectionSort("Thing");
foreach (Something thing in something)
Console.WriteLine("\t" + thing);
Console.WriteLine("\n\tStock items sorted by value");
something = something.SelectionSort("Value");
foreach (Something thing in something)
Console.WriteLine("\t" + thing);
Console.Write("\n\tPress any key to exit ...");
Console.ReadKey();
}
I have a struct
public struct Something
{
public string Thing { get; set; }
public decimal Price { get; set; }
}
And a generic container class called things
public class Things<T> : IEnumerable<T>
{
private List<T> lstItems;
public int Count { get { return lstItems.Count; } }
public Things() { lstItems = new List<T>(); }
public Things(List<T> items_) { lstItems = new List<T>(items_); }
public void Add(T item)
{
lstItems.Add(item);
}
public T this[int i]
{
get { return lstItems[i]; }
set { lstItems[i] = value; }
}
IEnumerator IEnumerable.GetEnumerator()
{
throw new System.NotImplementedException();
}
public IEnumerator<T> GetEnumerator()
{
foreach (T item in lstItems)
yield return item;
}
}
An extensions class extends the generic container class
public static class ExtensionsClass
{
private static string SortFiield { get; set; }
private static object GetProperty<T>(T thing, string nameofProp)
{
return thing.GetType().GetProperty(nameofProp).GetValue(thing, null);
}
private static int Compare<T>(T x, T y)
{
IComparable propX = (IComparable)GetProperty(x, SortFiield);
IComparable propY = (IComparable)GetProperty(y, SortFiield);
return propX.CompareTo(propY);
}
public static Things<T> SelectionSort<T>(this Things<T> things, string SORTFIELD)
{
List<T> lsstt = new List<T>(things);
int iIndex;
T temporary;
SortFiield = SORTFIELD;
for (int i = 0; i < lsstt.Count - 1; i++)
{
iIndex = i;
for (int j = i + 1; j < lsstt.Count; j++)
{
string first = GetProperty(lsstt[j], SortFiield).ToString();
string second = GetProperty(lsstt[iIndex], SortFiield).ToString();
if (Compare(first, second) < 0)
iIndex = j;
}
temporary = lsstt[i];
lsstt[i] = lsstt[iIndex];
lsstt[iIndex] = temporary;
}
return new Things<T>(lsstt);
}
}
The problem i am encountering is that get property in the extension class returns null, but i know that the object i am trying to return exists. It is found by the "String first = ...." line but when getproperty is called from the Compare method then it returns null.

You are passing "first", "second" to Compare. In your case both of them are strings and not objects, you need to pass "lsstt[j]" and "lsstt[iIndex]" to it.
if (Compare(lsstt[j], lsstt[iIndex]) < 0)
iIndex = j;

C# Compare two list and return value

I have a problem. I try compare two list currentItemsInColl and bPList. Inside bPList i have other list RequiredItems and now is what I need.
I want compare currentItemsInColl and RequiredItems and return bPList.craftingBlueprint.
I try Compare but I dont know how use it :/
using Devdog.InventoryPro;
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class CraftingAutoUpdate : MonoBehaviour {
public ItemCollectionBase itemCollection;
public ItemCollectionBase rewardCollection;
public CraftingCategory craftingCategory;
[Header("Blue Print List")]
public List<BlueprintList> bPList = new List<BlueprintList>();
public List<CurrentItemInCollList> currentItemsInColl = new List<CurrentItemInCollList>();
private CraftingBlueprint readyBlueprint;
public void OnShow()
{
GetBluePrint();
InvokeRepeating("StartUpdate",0f,0.05f);
}
public void OnHide()
{
CancelInvoke("StartUpdate");
}
private void StartUpdate()
{
UpdateDirectory();
UpdateFindMatchItems();
UpdateCraftResults();
}
private void GetBluePrint()
{
bPList.Clear();
foreach (var b in craftingCategory.blueprints)
{
if (b != null)
{
var rI = b.requiredItems;
var listReqItems = new List<RequiredItem>();
foreach (var e in rI)
{
listReqItems.Add(new RequiredItem(e.item.ID, e.amount));
}
bPList.Add(new BlueprintList(b.name, b, listReqItems));
}
}
}
private void UpdateDirectory()
{
currentItemsInColl.Clear();
foreach(var item in itemCollection)
{
if (item.item != null)
{
var cT = item.item.ID;
if (currentItemsInColl.Find(u =>u.itemID == cT) == null)
{
var itemCount = itemCollection.GetItemCount(item.item.ID);
currentItemsInColl.Add(new CurrentItemInCollList(item.item.ID, itemCount));
}
}
}
}
In this methode I try find same items in collections:
private void UpdateFindMatchItems()
{
readyBlueprint = null;
bool matchFailed = false;
int requiredItemCount = 0;
int currentItemsInCollCount = currentItemsInColl.Count;
foreach(var bp in bPList)
{
requiredItemCount = bp.RequiredItems.Count;
foreach(var rI in bp.RequiredItems)
{
if(CompareLists(currentItemsInColl, bp.RequiredItems))
{
print("aa");
}
print(currentItemsInCollCount);
}
}
private void UpdateCraftResults()
{
rewardCollection.Clear();
if (readyBlueprint != null)
{
foreach (var items in readyBlueprint.resultItems)
{
rewardCollection.AddItem(items.item,null,true,false);
}
}
}
I try somthing like this but is wont work with this lists:
public static bool CompareLists<T>(List<T> aListA, List<T> aListB)
{
if (aListA == null || aListB == null || aListA.Count != aListB.Count)
return false;
if (aListA.Count == 0)
return true;
Dictionary<T,T> lookUp = new Dictionary<T,T>();
// create index for the first list
for (int i = 0; i < aListA.Count; i++)
{
uint count = 0;
if (!lookUp.TryGetValue(aListA[i], out count))
{
lookUp.Add(aListA[i], 1);
continue;
}
lookUp[aListA[i]] = count + 1;
}
for (int i = 0; i < aListB.Count; i++)
{
uint count = 0;
if (!lookUp.TryGetValue(aListB[i], out count))
{
// early exit as the current value in B doesn't exist in the lookUp (and not in ListA)
return false;
}
count--;
if (count <= 0)
lookUp.Remove(aListB[i]);
else
lookUp[aListB[i]] = count;
}
// if there are remaining elements in the lookUp, that means ListA contains elements that do not exist in ListB
return lookUp.Count == 0;
}
}
And this is my lists:
/* LISTS */
[Serializable]
public class CurrentItemInCollList
{
public uint itemID;
public uint itemAmount;
public CurrentItemInCollList(uint newitemID, uint newItemAmount)
{
itemID = newitemID;
itemAmount = newItemAmount;
}
}
[Serializable]
public class BlueprintList
{
public string bluePrintName;
public CraftingBlueprint craftingBlueprint;
public List<RequiredItem> RequiredItems = new List<RequiredItem>();
public BlueprintList(string newBluePrintName, CraftingBlueprint newcraftingBlueprint, List<RequiredItem> list)
{
bluePrintName = newBluePrintName;
craftingBlueprint = newcraftingBlueprint;
RequiredItems = list;
}
}
[Serializable]
public class RequiredItem
{
public uint itemID;
public uint itemAmount;
public RequiredItem( uint newitemID, uint newItemAmount)
{
itemID = newitemID;
itemAmount = newItemAmount;
}
}
I forgot.. CurrentItemInCollList.itemAmount can be >= RequiredItems.itemAmount

Dictionary use hash values to compare objects.
The stored classes must implement public override int GetHashCode(){}

Use Linq - here is a small console example:
class Program
{
static void Main(string[] args)
{
//Required list
List<Order> currentItemsInColl = new List<Order>();
currentItemsInColl.Add(new Order() { Name = "bike1", Id = "01" });
currentItemsInColl.Add(new Order() { Name = "bike4", Id = "04" });
//List of all items
List<BPP> bPList = new List<BPP>();
bPList.Add(new BPP() { BikeName = "bike1", Idzzz = "01" });
bPList.Add(new BPP() { BikeName = "bike2", Idzzz = "02" });
bPList.Add(new BPP() { BikeName = "bike3", Idzzz = "03" });
bPList.Add(new BPP() { BikeName = "bike4", Idzzz = "04" });
bPList.Add(new BPP() { BikeName = "bike5", Idzzz = "05" });
//Blueprint List
List<BPP> Blueprint = new List<BPP>();
//get all items into the Blueprint list
foreach (Order i in currentItemsInColl)
{
List<BPP> tmp = bPList.FindAll(x => x.Idzzz.Contains(i.Id));
//here you add them all to a list
foreach (BPP item in tmp)
{
Blueprint.Add(item);
}
}
Console.ReadLine();
}
}
public class Order
{
public string Id { get; set; }
public string Name { get; set; }
}
public class BPP
{
public string Idzzz { get; set; }
public string BikeName { get; set; }
}
Sidenote: i am comparing the ID's in each of the lists! Hope it helps.

Using an Object as Key for a SortedList<Object,Value> in c#

How would you define an Object as Key to a SortedList in c#.
Here I would like to definte a Key Object like this
MyKey key = new MyKey();
key.type = 3; // can be 3,2 or 1
key.time = 2014-05-03 // DateTime in c# with timestamp
key.sequence = 5567 // a number unique to the combination above
I would like to sort this sorted list on priority type, time and sequence. How do i achieve this?

The SortedList in C# uses the IComparable interface for sorting the list. So for you to achieve this u must implement the IComparable interface. See: https://msdn.microsoft.com/en-us/library/system.icomparable.compareto(v=vs.110).aspx
A example:
public class Key : IComparable
{
public int Type {get; set; }
public DateTime Time { get; set; }
public int Sequence { get; set; }
int IComparable.CompareTo(object obj)
{
Key otherKey = obj as Key;
if (otherKey == null) throw new ArgumentException("Object is not a Key!");
if (Type > otherKey.Type)
return 1;
return -1;
}
}
Use the sorted list:
SortedList<Key,string> collection = new SortedList<Key, string>();
collection.Add(new Key { Type = 2 }, "alpha");
collection.Add(new Key { Type = 1 }, "beta");
collection.Add(new Key { Type = 3 }, "delta");
foreach (string str in collection.Values)
{
Console.WriteLine(str);
}
This writes:
beta
alpha
delta

Create a custom Comparer<myKey> and pass that to the SortedList constructor:
public class TypeComparer : Comparer<MyKey>
{
public override int Compare(MyKey x, MyKey y)
{
if (ReferenceEquals(x, y)) return 0;
int typeX = int.MinValue;
int typeY = int.MinValue;
if (x != null) typeX = x.type;
if (y != null) typeY = y.type;
return typeX.CompareTo(typeY);
}
}
Now you can use this constructor:
var sl = new SortedList<MyKey, string>(new TypeComparer());

If I understand correctly:
static void Main(string[] args)
{
Dictionary<MyKey, string> fooDictionary = new Dictionary<MyKey, string>();
fooDictionary.Add(new MyKey() {FooNumber=1, Sequence=50 }, "1");
fooDictionary.Add(new MyKey() { FooNumber = 2, Sequence = 40 }, "2");
fooDictionary.Add(new MyKey() { FooNumber = 3, Sequence = 30 }, "3");
fooDictionary.Add(new MyKey() { FooNumber = 4, Sequence = 20 }, "4");
fooDictionary.Add(new MyKey() { FooNumber = 5, Sequence = 10 }, "5");
var result = from c in fooDictionary orderby c.Key.Sequence select c;
Console.WriteLine("");
}
class MyKey
{
public int FooNumber { get; set; }
public DateTime MyProperty { get; set; }
public int Sequence { get; set; }
}

Processing ranking data w/ C# & LINQ

I have an object in a list that I need to rank several different ways. Currently the code is rather unwieldy as it requires me to individually address each column. Example:
public class Data
{
public int AValue { get; set; }
public int ARanking { get; set; }
public int BValue { get; set; }
public int BRanking { get; set; }
public int CValue { get; set; }
public int CRanking { get; set; }
}
public class Container
{
public List<Data> RankingData { get; set; }
public void RankData()
{
int count = 1;
foreach (Data item in RankingData.OrderBy(d => d.AValue))
{
item.ARanking = count;
count++;
}
count = 1;
foreach (Data item in RankingData.OrderBy(d => d.BValue))
{
item.BRanking = count;
count++;
}
count = 1;
foreach (Data item in RankingData.OrderBy(d => d.CValue))
{
item.CRanking = count;
count++;
}
}
}
The problem I am trying to solve is I want to write something roughly like this:
public void RankData<V, R>()
{
int count = 1;
foreach(Data item in RankingData.OrderBy(V))
{
item.R = count;
count++;
}
}
So that as I need to alter the ranking logic (for example, handle tie breaking rules) that I write the code once instead of copying the code 20 times to make the rules match. What am I missing?
UPDATE
Using Tanzelax's solution as a base this is the extension class I came up with:
public static class RankingExtension
{
public static void SetRanking<TKey>(this List<Data> dataSet, bool Ascending, Func<Data, TKey> getOrderBy, Action<Data, int> setRank)
where TKey : IComparable
{
var ordered = (Ascending) ? dataSet.OrderBy(getOrderBy) : dataSet.OrderByDescending(getOrderBy);
int i = 1;
foreach (Data item in ordered)
{
setRank(item, i);
i++;
}
}
}
I had to add in a switch so that I could control whether or not the field was being sorted ascending or not. And in my test scenarios it produces the appropriate output:
List<Data> test = new List<Data>();
test.Add(new Data { AValue = 25, BValue = 1.25, CValue = 99.99 });
test.Add(new Data { AValue = 89, BValue = 2.10, CValue = 1.01 });
test.Add(new Data { AValue = 10, BValue = 6, CValue = 45.45 });
test.Add(new Data { AValue = 15, BValue = 2.33, CValue = 2.99 });
test.Add(new Data { AValue = 90, BValue = 5.43, CValue = 27.89 });
test.SetRanking(false, d => d.AValue, (d, i) => d.ARank = i);
test.SetRanking(false, d => d.BValue, (d, i) => d.BRank = i);
test.SetRanking(true, d => d.CValue, (d, i) => d.CRank = i);

Not tested, but something like this:
void SetRanking(this List<Data> dataSet, Func<Data,int> getOrderBy, Action<Data,int> setRank)
{
var ordered = dataSet.OrderBy(getOrderBy).ToArray();
int i = i;
foreach (Data item in ordered)
{
setRank(item, i);
i++;
}
}
RankingData.SetRanking(d => d.AValue, (d,i) => d.ARanking = i);
RankingData.SetRanking(d => d.BValue, (d,i) => d.BRanking = i);
RankingData.SetRanking(d => d.CValue, (d,i) => d.CRanking = i);

This is similar to Tanzelax's answer but is a generic extension method.
public static void RankData<TSource, TKey>(
this IEnumerable<TSource> source,
Func<TSource, TKey> keySelector,
Action<TSource, int> rankSetter
)
{
int count = 1;
foreach (var item in source.OrderBy(keySelector))
{
rankSetter(item, count);
++count;
}
}
It would be called similar to Tanzelax's answer also.
RankingData.RankData(d => d.AValue, (d,i) => d.ARanking = i);

Pass in a Func<Data,K> that returns the ranking key. K should implement IComparable
public static void Rank<K>( IEnumerable<Data> source, Func<Data,K> rankBy ) where K : IComparable
{
int count = 1;
foreach (var item in source.OrderBy( rankBy ))
{
item.R = count;
++count;
}
}

How do I use the IComparable interface?

I need a basic example of how to use the IComparable interface so that I can sort in ascending or descending order and by different fields of the object type I'm sorting.

Well, since you are using List<T> it would be a lot simpler to just use a Comparison<T>, for example:
List<Foo> data = ...
// sort by name descending
data.Sort((x,y) => -x.Name.CompareTo(y.Name));
Of course, with LINQ you could just use:
var ordered = data.OrderByDescending(x=>x.Name);
But you can re-introduce this in List<T> (for in-place re-ordering) quite easily; Here's an example that allows Sort on List<T> with lambda syntax:
using System;
using System.Collections.Generic;
class Foo { // formatted for vertical space
public string Bar{get;set;}
}
static class Program {
static void Main() {
List<Foo> data = new List<Foo> {
new Foo {Bar = "abc"}, new Foo {Bar = "jkl"},
new Foo {Bar = "def"}, new Foo {Bar = "ghi"}
};
data.SortDescending(x => x.Bar);
foreach (var row in data) {
Console.WriteLine(row.Bar);
}
}
static void Sort<TSource, TValue>(this List<TSource> source,
Func<TSource, TValue> selector) {
var comparer = Comparer<TValue>.Default;
source.Sort((x,y)=>comparer.Compare(selector(x),selector(y)));
}
static void SortDescending<TSource, TValue>(this List<TSource> source,
Func<TSource, TValue> selector) {
var comparer = Comparer<TValue>.Default;
source.Sort((x,y)=>comparer.Compare(selector(y),selector(x)));
}
}

Here's a simple example:
public class SortableItem : IComparable<SortableItem>
{
public int someNumber;
#region IComparable<SortableItem> Members
public int CompareTo(SortableItem other)
{
int ret = -1;
if (someNumber < other.someNumber)
ret = -1;
else if (someNumber > other.someNumber)
ret = 1;
else if (someNumber == other.someNumber)
ret = 0;
return ret;
}
#endregion
}
"That's great, but what if I want to be able to control the sort order, or sort by another field?"
Simple. All we need to do is add few more fields to the object. First we'll add a string for a different sort type and then we'll add a boolean to denote whether we're sorting in descending or ascending order and then add a field which determines which field we want to search by.
public class SortableItem : IComparable<SortableItem>
{
public enum SortFieldType { SortNumber, SortString }
public int someNumber = -1;
public string someString = "";
public bool descending = true;
public SortFieldType sortField = SortableItem.SortFieldType.SortNumber;
#region IComparable<SortableItem> Members
public int CompareTo(SortableItem other)
{
int ret = -1;
if(sortField == SortableItem.SortFieldType.SortString)
{
// A lot of other objects implement IComparable as well.
// Take advantage of this.
ret = someString.CompareTo(other.someString);
}
else
{
if (someNumber < other.someNumber)
ret = -1;
else if (someNumber > other.someNumber)
ret = 1;
else if (someNumber == other.someNumber)
ret = 0;
}
// A quick way to switch sort order:
// -1 becomes 1, 1 becomes -1, 0 stays the same.
if(!descending) ret = ret * -1;
return ret;
}
#endregion
public override string ToString()
{
if(sortField == SortableItem.SortFieldType.SortString)
return someString;
else
return someNumber.ToString();
}
}
"Show me how!"
Well since you asked so nicely.
static class Program
{
static void Main()
{
List<SortableItem> items = new List<SortableItem>();
SortableItem temp = new SortableItem();
temp.someString = "Hello";
temp.someNumber = 1;
items.Add(temp);
temp = new SortableItem();
temp.someString = "World";
temp.someNumber = 2;
items.Add(temp);
SortByString(items);
Output(items);
SortAscending(items);
Output(items);
SortByNumber(items);
Output(items);
SortDescending(items);
Output(items);
Console.ReadKey();
}
public static void SortDescending(List<SortableItem> items)
{
foreach (SortableItem item in items)
item.descending = true;
}
public static void SortAscending(List<SortableItem> items)
{
foreach (SortableItem item in items)
item.descending = false;
}
public static void SortByNumber(List<SortableItem> items)
{
foreach (SortableItem item in items)
item.sortField = SortableItem.SortFieldType.SortNumber;
}
public static void SortByString(List<SortableItem> items)
{
foreach (SortableItem item in items)
item.sortField = SortableItem.SortFieldType.SortString;
}
public static void Output(List<SortableItem> items)
{
items.Sort();
for (int i = 0; i < items.Count; i++)
Console.WriteLine("Item " + i + ": " + items[i].ToString());
}
}

If you want dynamic sort, you can use LINQ
var itemsOrderedByNumber = ( from item in GetClasses() orderby item.Number select item ).ToList();
var itemsOrderedByText = ( from item in GetClasses() orderby item.Text select item ).ToList();
var itemsOrderedByDate = ( from item in GetClasses() orderby item.Date select item ).ToList();
or "Sort" method of List class:
List<Class1> itemsOrderedByNumber2 = new List<Class1>( GetClasses() );
itemsOrderedByNumber2.Sort( ( a, b ) => Comparer<int>.Default.Compare( a.Number, b.Number ) );
List<Class1> itemsOrderedByText2 = new List<Class1>( GetClasses() );
itemsOrderedByText2.Sort( ( a, b ) => Comparer<string>.Default.Compare( a.Text, b.Text ) );
List<Class1> itemsOrderedByDate2 = new List<Class1>( GetClasses() );
itemsOrderedByDate2.Sort( ( a, b ) => Comparer<DateTime>.Default.Compare( a.Date, b.Date ) );

You can use this for sorting list
namespace GenaricClass
{
class Employee :IComparable<Employee>
{
public string Name { get; set; }
public double Salary { get; set; }
public int CompareTo(Employee other)
{
if (this.Salary < other.Salary) return 1;
else if (this.Salary > other.Salary) return -1;
else return 0;
}
public static void Main()
{
List<Employee> empList = new List<Employee>()
{
new Employee{Name="a",Salary=140000},
new Employee{Name="b",Salary=120000},
new Employee{Name="c",Salary=160000},
new Employee{Name="d",Salary=10000}
};
empList.Sort();
foreach (Employee emp in empList)
{
System.Console.Write(emp.Salary +",");
}
System.Console.ReadKey();
}
}
}

This might not be in relation to sorting order, but it is still - I think - an interesting use of IComparable:
public static void MustBeInRange<T>(this T x, T minimum, T maximum, string paramName)
where T : IComparable<T>
{
bool underMinimum = (x.CompareTo(minimum) < 0);
bool overMaximum = (x.CompareTo(maximum) > 0);
if (underMinimum || overMaximum)
{
string message = string.Format(
System.Globalization.CultureInfo.InvariantCulture,
"Value outside of [{0},{1}] not allowed/expected",
minimum, maximum
);
if (string.IsNullOrEmpty(paramName))
{
Exception noInner = null;
throw new ArgumentOutOfRangeException(message, noInner);
}
else
{
throw new ArgumentOutOfRangeException(paramName, x, message);
}
}
}
public static void MustBeInRange<T>(this T x, T minimum, T maximum)
where T : IComparable<T> { x.MustBeInRange(minimum, maximum, null); }
These simple extension methods allow you to do parameter range checking for any type that implements IComparable like this:
public void SomeMethod(int percentage, string file) {
percentage.MustBeInRange(0, 100, "percentage");
file.MustBeInRange("file000", "file999", "file");
// do something with percentage and file
// (caller will have gotten ArgumentOutOfRangeExceptions when applicable)
}

using System;
using System.Collections.Generic;
using System.Text;
namespace Sorting_ComplexTypes
{
class Program
{
static void Main(string[] args)
{
Customer customer1 = new Customer {
ID = 101,
Name = "Mark",
Salary = 2400,
Type = "Retail Customers"
};
Customer customer2 = new Customer
{
ID = 102,
Name = "Brian",
Salary = 5000,
Type = "Retail Customers"
};
Customer customer3 = new Customer
{
ID = 103,
Name = "Steve",
Salary = 3400,
Type = "Retail Customers"
};
List<Customer> customer = new List<Customer>();
customer.Add(customer1);
customer.Add(customer2);
customer.Add(customer3);
Console.WriteLine("Before Sorting");
foreach(Customer c in customer)
{
Console.WriteLine(c.Name);
}
customer.Sort();
Console.WriteLine("After Sorting");
foreach(Customer c in customer)
{
Console.WriteLine(c.Name);
}
customer.Reverse();
Console.WriteLine("Reverse Sorting");
foreach (Customer c in customer)
{
Console.WriteLine(c.Name);
}
}
}
}
public class Customer : IComparable<Customer>
{
public int ID { get; set; }
public string Name { get; set; }
public int Salary { get; set; }
public string Type { get; set; }
public int CompareTo(Customer other)
{
return this.Name.CompareTo(other.Name);
}
}