Develop Reference

c# using other class method

Thanks to NHMountainGoat for an answer!
Implementing Interface looks a good choice so we have only the 'needed' method instanciated.
It looks like this now:
EDIT
class Machine
{
//REM: MachineConnexion is a link to the main server where asking the data
internal linkToPLC LinkToPLC;
public IlinkToPLC ILinkPLC;
public interface IlinkToPLC//Interface to linkPLC
{
Int16 MachineNumIS { get; set; }
}
internal class linkToPLC : IlinkToPLC
{
private Int16 Act_MachineNum;
private List<string> genlnkPLCCanvas;
private List<string> genlnkPLCworkingwith;
static private List<string> ListSymbolNoExist;
private string[] ListToPLClnk = {
"GlobalFolder.PMachine[{0}].",
"GlobalFolder.PMachine[{0}].STATE.",
"GlobalFolder.Machine[{0}].",
"GlobalFolder.Machine[{0}].STATE.",
};
public linkToPLC()//ctor
{
genlnkPLCCanvas = new List<string>(ListToPLClnk);
genlnkPLCworkingwith = new List<string>(ListToPLClnk);
ListSymbolNoExist = new List<string>();
Act_MachineNum = MachineNumIS;
}
public Int16 MachineNumIS { get { return (Int16)ReadWriteMachine("data"); } set { ReadWriteMachine("data", value); } }
public string ValueExist(string ValueToreach, bool WorkingDATA = false)
{
if (!WorkingDATA)
{
for (int inc = 0; inc < genlnkPLCworkingwith.Count; inc++)
{
string StrValueToReach = genlnkPLCworkingwith[inc] + ValueToreach;
if (MachineConnexion.SymbolExists(StrValueToReach))
{
ListSymbolNoExist.Clear();
return StrValueToReach;
}
else ListSymbolNoExist.Add(genlnkPLCworkingwith[inc] + ValueToreach);
}
}
else if (WorkingDATA)
{
string StrValueToReach = genlnkPLCworkingwith[10] + ValueToreach;
if (MachineConnexion.SymbolExists(StrValueToReach))
{
ListSymbolNoExist.Clear();
return StrValueToReach;
}
else ListSymbolNoExist.Add(genlnkPLCworkingwith[10] + ValueToreach);
}
if (ListSymbolNoExist.Count != 0)
{
string ErrorList = "";
for (int inc = 0; inc < ListSymbolNoExist.Count; inc++)
{
ErrorList = string.Concat(ErrorList + "Num: " + inc.ToString() + " " + ListSymbolNoExist[inc].ToString() + "\n");
}
Console.WriteLine("Error" + ErrorList);
}
return null;
}
public object ReadWriteMachine(string VariableName, object DataToWrite = null, bool WorkingDATA = false)
{
string valueToFind = "";
if (ValueExist(VariableName) != "FALSE")
{
if (DataToWrite != null) { MachineConnexion.WriteSymbol(valueToFind, DataToWrite); }
return MachineConnexion.ReadSymbol(valueToFind);
}
return VariableName;
}
}
public Machine() //constructor
{
LinkToPLC = new linkToPLC();
}
}
And It doesn't work telling me that the reference object is not defined to an instance of the object..... in the line : Machine() LinkToPLC = new linkToPLC();//REM I found the bug, it was me ;o)) 24112016
//REM 24112016
What are the main differences between those two concept: static Instance and Interface?
Example:
class Program
{
static void Main(string[] args)
{
ITestInterface InterInstance = new TestInterface();
//test Interface
bool value1 = true;
value1 = InterInstance.invert(value1);
InterInstance.print(value1);
//test Instance static
TestStaticInstance staticInstance = new TestStaticInstance();
staticInstance.Instance.invert(value1);
staticInstance.Instance.print(value1);
Console.ReadKey();
}
}
class TestInterface : ITestInterface
{
public bool invert(bool value)
{
return !value;
}
public void print(bool value)
{
Console.WriteLine(value.ToString()+"\n");
}
private void methodX()
{ }
}
interface ITestInterface
{
bool invert(bool value);
void print(bool value);
}
public class TestStaticInstance
{
public TestStaticInstance Instance;
public TestStaticInstance()
{
Instance = this;
}
internal bool invert(bool value)
{
return !value;
}
internal void print(bool value)
{
Console.WriteLine(value.ToString());
}
}
Thanks

Can you structure your other classes to take an instance of the link class? See:
/// <summary>
/// just a stub to demonstrate the model
/// </summary>
internal class Machine
{
public string ReadData() { return "this is data"; }
public void WriteData(string data) { Console.WriteLine(data); }
}
internal interface IMachineDataAccessor
{
string Read();
void Write(string data);
}
class LinkClass : IMachineDataAccessor
{
protected Machine _machine;
public LinkClass(Machine machine)
{
_machine = machine;
}
public void DoMyWork()
{
// insert work somewhere in here.
string dataFromMachine = Read();
Write("outbound data");
}
public string Read()
{
return _machine.ReadData();
}
public void Write(string data)
{
_machine.WriteData(data);
}
}
class PersistentClass
{
IMachineDataAccessor _machineImpl;
public PersistentClass(IMachineDataAccessor machineAccessImplementation)
{
_machineImpl = machineAccessImplementation;
}
public void DoMyWork()
{
string dataFromMachine = _machineImpl.Read();
// insert work here. Or anywhere, actually..
_machineImpl.Write("outbound data");
}
}
class StateClass
{
IMachineDataAccessor _machineImpl;
public StateClass(IMachineDataAccessor machineAccessImplementation)
{
_machineImpl = machineAccessImplementation;
}
public void DoMyWork()
{
string dataFromMachine = _machineImpl.Read();
// insert work here. Or anywhere, actually..
_machineImpl.Write("outbound data");
}
}
static void Main(string[] args)
{
LinkClass link = new LinkClass(new Machine());
PersistentClass persistent = new PersistentClass(link as IMachineDataAccessor);
StateClass state = new StateClass(link as IMachineDataAccessor);
persistent.DoMyWork();
state.DoMyWork();
link.DoMyWork();
}

Linq sorting of entity by custom property via reflection

Got Customer class which has Country property which has string property Name.
Also Customer implements IComparable<Country> like so:
public int CompareTo(Country other)
{
return string.Compare(this.Name, other.Name);
}
Now:
var custList = new List<Customer>{...};
custList.OrderBy(cust => cust.Country).ToList(); //Sorts as charm.
And if try sorting via reflection:
var itemProp = typeof(Customer).GetProperty("Country");
custList = c.Customers.ToList()
.OrderBy(cust => itemProp.GetValue(cust, null)).ToList(); // Fails
Throws exception 'At least one object must implement IComparable'
Please explain why does it fail and how correctly implement sorting of Customer by custom property via reflection. Thanks.

Since GetValue returns Object you need to implement the non generic version of IComparable.
void Main()
{
var custList = new List<Customer>()
{
new Customer(){ Country = new Country(){ Name = "Sweden" } },
new Customer(){ Country = new Country(){ Name = "Denmark" } },
};
var itemProp = typeof(Customer).GetProperty("Country");
custList = custList.OrderBy(cust => itemProp.GetValue(cust, null)).ToList();
custList.Dump();
}
public class Country : IComparable<Country>, IComparable
{
public string Name {get;set;}
public int CompareTo(Country other)
{
return string.Compare(this.Name, other.Name);
}
public int CompareTo(object other)
{
var o = other as Country;
if(o == null)
return 0; //Or how you want to handle it
return CompareTo(o);
}
}
public class Customer
{
public Country Country{get;set;}
}

Assuming that the underlying type is correct (i.e. Country), you should be able to do it as long as Country implements IComparable:
Here's a sample console app that works correctly (note that there is no error handling):
using System;
using System.Collections.Generic;
using System.Linq;
namespace Demo
{
class Number: IComparable<Number>, IComparable
{
public Number(int value)
{
Value = value;
}
public readonly int Value;
public int CompareTo(Number other)
{
return Value.CompareTo(other.Value);
}
public int CompareTo(object obj)
{
return CompareTo((Number) obj);
}
}
class Test
{
public Number Number;
public object Obj
{
get { return Number; }
}
public override string ToString()
{
return Number.Value.ToString();
}
}
internal static class Program
{
static void Main()
{
var itemProp = typeof(Test).GetProperty("Obj");
Console.WriteLine(string.Join("\n",
data().OrderBy(x => itemProp.GetValue(x, null))));
}
static IEnumerable<Test> data()
{
for (int i = 0; i < 10; ++i)
yield return new Test {Number = new Number(10-i)};
}
}
}

Is there any way to create property dynamically in c#?

public class UserDetails
{
public string UserID { get; set; }
public string UserName { get; set; }
}
Here i want to add property dynamically. The type and property name would change dynamically, with those value i want to create property.

This seems to work but requires casting to get to the "flexible" properties.
The UserDetails class
public class UserDetails
{
private dynamic _internal;
public static implicit operator System.Dynamic.ExpandoObject(UserDetails details)
{
return details._internal;
}
public UserDetails()
{
_internal = new System.Dynamic.ExpandoObject();
}
public string UserID
{
get
{
return _internal.UserID;
}
set
{
_internal.UserID = value;
}
}
public string UserName
{
get
{
return _internal.UserName;
}
set
{
_internal.UserName = value;
}
}
}
And using the class
UserDetails user = new UserDetails();
user.UserName = "bill";
user.UserID = "1";
dynamic dynamicUser = (System.Dynamic.ExpandoObject)user;
dynamicUser.newMember = "check this out!";
Console.WriteLine(user.UserName);
Console.WriteLine(user.UserID);
Console.WriteLine(dynamicUser.UserName);
Console.WriteLine(dynamicUser.UserID);
Console.WriteLine(dynamicUser.newMember);

Yes, but it's complicated.
Check out implementing ICustomTypeDescriptor. If you make your base class implement it, you will be able to add properties dynamically. There are tutorials on the web, search for the interface on the web.
The 2nd thing can be to use the ExpandoObject.
In this way you can not inherit from a base class, but it is much simpler to implement.

It seems possible that all you really need is a "Property Bag", i.e. an unordered container into which you can insert name/value pairs where the name is a string and the value is any kind of object.
There are many implementations of PropertyBag available online; here's a quick and dirty one I threw together as an example:
using System;
using System.Collections;
using System.Collections.Generic;
using System.Drawing;
namespace Demo
{
public static class Program
{
private static void Main(string[] args)
{
var properties = new PropertyBag();
properties["Colour"] = Color.Red;
properties["π"] = Math.PI;
properties["UserId"] = "My User ID";
properties["UserName"] = "Matthew";
// Enumerate all properties.
foreach (var property in properties)
{
Console.WriteLine(property.Key + " = " + property.Value);
}
// Check if property exists:
if (properties["UserName"] != null)
{
Console.WriteLine("[UserName] exists.");
}
// Get a property:
double π = (double)properties["π"];
Console.WriteLine("Pi = " + π);
}
}
public sealed class PropertyBag: IEnumerable<KeyValuePair<string, object>>
{
public object this[string propertyName]
{
get
{
if (propertyName == null)
{
throw new ArgumentNullException("propertyName");
}
if (_dict.ContainsKey(propertyName))
{
return _dict[propertyName];
}
else
{
return null;
}
}
set
{
if (propertyName == null)
{
throw new ArgumentNullException("propertyName");
}
_dict[propertyName] = value;
}
}
public IEnumerator<KeyValuePair<string, object>> GetEnumerator()
{
return _dict.GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
private readonly Dictionary<string, object> _dict = new Dictionary<string, object>();
}
}

Object serializing/deserializing doesn't work

I have an extension method for System.Object to serialize and deserialize objects using Json.Net. this is my Extension methods:
public static void SaveToFile(this object data, string FileName)
{
using (StreamWriter writer = new StreamWriter(FileName))
{
string encode = WpfApplication.Helper.Encrypt(JsonConvert.SerializeObject(data));
writer.Write(encode);
writer.Close();
}
}
public static void LoadFromFile<t>(this object data, string FileName)
{
using (StreamReader reader = new StreamReader(FileName))
{
data = JsonConvert.DeserializeObject<t>(WpfApplication.Helper.Decrypt(reader.ReadToEnd()));
reader.Close();
}
}
and It's the class that I want to deserialize:
public class CardPack
{
#region Properties
private string name;
public string Name
{
get { return name; }
set { name = value; }
}
private List<FlashCard> cards;
public List<FlashCard> Cards
{
get { return cards; }
set { cards = value; }
}
private bool registered;
public bool Registered
{
get { return registered; }
set { registered = value; }
}
private int currentCardIndex;
public int CurrentCardIndex
{
get { return currentCardIndex; }
set { currentCardIndex = value; }
}
public string RegisterKey { get; set; }
public string ViewName { get; set; }
public List<FlashCard> TodayCards { get; set; }
#endregion
~CardPack()
{
foreach (FlashCard card in cards)
{
card.Check();
}
currentCardIndex = 0;
TodayCards = null;
this.SaveToFile(string.Format(System.IO.Path.GetDirectoryName(
System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase).Split(#"file:\\")[1] + #"\Packs\{0}.json", name));
}
but whenever I deserialize the class cards is empty and I don't know how to resolve the problem. Can anybody help me?
Update
I find the error when I had this code:
public CardPack(string Name)
{
this.name = Name;
this.LoadFromFile<CardPack>(string.Format(System.IO.Path.GetDirectoryName(
System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase).Split(#"file:\\")[1] + #"\Packs\{0}.json", name));
foreach (var item in cards)
{
if (item.NextTime == null)
{
int a = 0;
}
}
TodayCards = cards.Where(c => c.NextTime.Date == DateTime.Today).ToList();
}
because the application closed when it tries to run foreach (var item in cards)!
I asked here and found out that cards is empty!
update2 I serialized the CardPack object with a little different structure. in previous structure Cards property was read-only.

I found that data = JsonConvert.DeserializeObject<t>(WpfApplication.Helper.Decrypt(reader.ReadToEnd())); in extension method doesn't change to 'data' class then Cards in CardPack is always null. I'll ask a question to find out why I cant set the class from it's extension method later.

Casting to generic type in non-generic method

What I'm doing now:
void Main()
{
var command1 = new PersistenceCommand(new MyIntBO());
var command2 = new PersistenceCommand(new MyGuidBO());
var command3 = new PersistenceCommand(new PersistentBO());
Console.WriteLine(command1.ToString());
Console.WriteLine(command2.ToString());
Console.WriteLine(command3.ToString());
}
public class PersistenceCommand
{
public PersistenceCommand(PersistentBO businessObject)
{
_businessObject = businessObject;
}
public override string ToString()
{
string result = _businessObject.GetType().Name;
var keyed = _businessObject as IPrimaryKeyed<int>;
if (keyed != null)
{
result += " " + keyed.Id.ToString();
}
return result;
}
private readonly PersistentBO _businessObject;
}
public interface IPrimaryKeyed<out TKey>
{
TKey Id { get; }
}
public class PersistentBO {}
public class MyIntBO : PersistentBO, IPrimaryKeyed<int>
{
public int Id { get { return 1008; } }
}
public class MyGuidBO : PersistentBO, IPrimaryKeyed<Guid>
{
public Guid Id
{
get
{
return new Guid("6135d49b-81bb-43d4-9b74-dd84c2d3cc29");
}
}
}
This prints:
MyIntBO 1008
MyGuidBO
PersistentBO
I'd like it to print:
MyIntBO 1008
MyGuidBO 6135d49b-81bb-43d4-9b74-dd84c2d3cc29
PersistentBO
What's the most elegant way to do that?
I want to support all types of keys - int, long, Guid, etc. - so I'd rather not do multiple casts. Note that not every business object implements that interface (some do not have a single primary key).
I realize I could use reflection and try to access the Id property. I was wondering if there's a better solution.
Clarification: To address #Acaz Souza and #Petar Ivanov's answers, we have dozens of classes scattered over multiple assemblies that already implement IPrimaryKeyed<T>. I do not want to break all of them by extending the interface contract. If I were designing this from scratch, their solutions would work.

Just create a non-generic interface and replace the generic one with generic abstract class. Then check for the interface:
public interface IPrimaryKeyed
{
object ObjId { get; }
}
public abstract class PrimaryKeyed<TKey> : IPrimaryKeyed
{
public object ObjId { get { return Id; } }
public abstract TKey Id { get; }
}
---
public override string ToString()
{
string result = _businessObject.GetType().Name;
var keyed = _businessObject as IPrimaryKeyed;
if (keyed != null)
{
result += " " + keyed.ObjId.ToString();
}
return result;
}

Using reflection doesn't seem like a bad way to go here.
ToString method:
// for getting the Id prop
var identProp = _businessObject.GetType().GetProperty("Id");
string result = _businessObject.GetType().Name;
if (identProp != null)
{
result += " " + identProp.GetValue(_businessObject, null).ToString();
}

The problem is in that line:
var keyed = _businessObject as IPrimaryKeyed<int>;
Your other type is not IPrimaryKeyed<int> is IPrimaryKeyed<Guid>, then the if (keyed != null) is false.
You can try do this:
static void Main()
{
var command1 = new PersistenceCommand(new MyIntBO());
var command2 = new PersistenceCommand(new MyGuidBO());
var command3 = new PersistenceCommand(new PersistentBO());
Console.WriteLine(command1.ToString());
Console.WriteLine(command2.ToString());
Console.WriteLine(command3.ToString());
Console.ReadLine();
}
public class PersistenceCommand
{
public PersistenceCommand(PersistentBO businessObject)
{
_businessObject = businessObject;
}
public override string ToString()
{
string result = _businessObject.GetType().Name;
var keyed = _businessObject as IPrimaryKeyed;
if (keyed != null)
{
result += " " + keyed.Id.ToString();
}
return result;
}
private readonly PersistentBO _businessObject;
}
public interface IPrimaryKeyed
{
object Id { get; }
}
public class PersistentBO { }
public class MyIntBO : PersistentBO, IPrimaryKeyed
{
public object Id { get { return 1008; } }
}
public class MyGuidBO : PersistentBO, IPrimaryKeyed
{
public object Id { get { return new Guid("6135d49b-81bb-43d4-9b74-dd84c2d3cc29"); } }
}