Develop Reference

how to cast a generic type to another type?

As shown in the first class displayed, I need to cast Activité to Réunion (Réunion extends Activité) but the compiler tells me that I can't. Why? I'll put a scheme so you can better understand my classes structure and also all my other classes. Thank you.
class Employé<T>
{
private string nom;
private Local bureau;
private LinkedList<Activité<T>> activités;
public Employé(string nom, Local bureau)
{
this.nom = nom;
this.bureau = bureau;
}
public void AjouteActivité(params Activité<T>[] activités)
{
foreach(Activité<T> activité in activités)
{
if (activité as Réunion != null)
// here's the problem !!! ((Réunion)activité).EmployéConvoqués = activité;
}
}
}
Here's the scheme of my classes structure:
And here are the other classes:
abstract class Activité<T>
{
private string label;
private DateTime début, fin;
private T lieu;
private readonly int id;
private static int CPT = 0;
public Activité(string label, DateTime début, DateTime fin, T lieu)
{
this.label = label;
this.début = début;
this.fin = fin;
this.lieu = lieu;
this.id = ++CPT;
}
public override string ToString()
{
return $"{id} : {label}(de {début} à {fin}) - {DescriptionLieu()}";
}
public double Duree()
{
return fin.Subtract(début).TotalMinutes;
}
public int Id
{
//tester get; seulement
get
{
return id;
}
}
public T Lieu
{
get
{
return lieu;
}
}
public abstract string DescriptionLieu();
}
class ActivitéExtérieure : Activité<string>
{
public ActivitéExtérieure(string label, DateTime début, DateTime fin, string lieu) : base(label,début,fin,lieu) { }
public override string DescriptionLieu()
{
return Lieu;
}
}
class ActivitéInterne : Activité<Local>
{
public ActivitéInterne(string label, DateTime début, DateTime fin, Local lieu) : base(label,début,fin,lieu)
{
lieu.AjouteActivité(this);
}
public override string DescriptionLieu()
{
return $"local :: {Lieu.NumComplet}";
}
}
class Employé<T>
{
private string nom;
private Local bureau;
private LinkedList<Activité<T>> activités;
public Employé(string nom, Local bureau)
{
this.nom = nom;
this.bureau = bureau;
}
public void AjouteActivité(params Activité<T>[] activités)
{
foreach(Activité<T> activité in activités)
{
if (activité as Réunion != null)
((Réunion)activité).EmployéConvoqués = activité;
}
}
}
class Local
{
private int etage;
private int numero;
private bool possedeWifi;
private Dictionary<int, ActivitéInterne> historiquesActivités;
public int Numero
{
get
{
return numero;
}
set
{
if (value < 0 || value > 99)
throw new IndexOutOfRangeException();
else
numero = value;
}
}
public int NumComplet
{
get
{
return etage * 100 + numero;
}
}
public bool PossedeWifi
{
get
{
return possedeWifi;
}
}
public Local(int etage, bool possedeWifi, int numero)
{
this.etage = etage;
this.possedeWifi = possedeWifi;
Numero = numero;
}
public Local(int etage, int numero) : this(etage, true, numero) { }
public Local(int local, bool possedeWifi) : this(local / 100, possedeWifi, local % 100) { }
public void AjouteActivité(ActivitéInterne a)
{
historiquesActivités.Add(a.Id, a);
}
}
class Réunion : ActivitéInterne
{
private HashSet<Employé<Local>> employésConvoqués;
public Réunion(string label, DateTime début, DateTime fin, Local lieu) : base(label, début, fin, lieu) { }
public Employé<Local> EmployéConvoqués
{
set
{
employésConvoqués.Add(value);
}
}
}

The error message says that "cast is redundant". This is because you have already tested for "activité as Réunion != null". The compiler figures out that in the 'if' clause this condition is already true, therefore the cast is not meaningful. On the other hand you cannot access activité.EmployéConvoqués because the static type of activité is not Réunion.
All you have to do is introduce a new variable when testing the type. Like this:
if (activité is Réunion réunion) {
réunion.EmployéConvoqués = activité;
}
However if you try this you will see that the assignment cannot be done because you are trying to assign an activity to an Employé<Local>. These are not compatible types. Perhaps you meant something like
foreach (Activité<T> activité in activités) {
if (activité is Réunion réunion && this is Employé<Local> employéLocal) {
réunion.EmployéConvoqués = employéLocal;
}
}
Comment: in the definition of Réunion you are adding to HashSet<Employé<Local>> employésConvoqués when setting the property Employé<Local> EmployéConvoqués. From a style point of view this is strange because people generally expect a property of type Employé<Local> will represent a single Employé<Local> rather than a collection of Employé<Local>. I would suggest that you remove the setter and instead define
public void Ajoute( Employé<Local> employéConvoqué) {
this.employésConvoqués.Add(employéConvoqué);
}

Neo4jClient Node/Relationship Class conventions

Is there a standard naming convention for the properties/methods of a node/relationship class when working with Neo4jClient?
I'm following this link Neo4jClient - Retrieving relationship from Cypher query to create my relationship class
However, there are certain properties of my relationship which i can't get any value despite the relationship having it. While debugging my code, i realized certain properties was not retrieved from the relationship when creating the relationship object.
this is my relationship class
public class Creates
{
private string _raw;
private int _sourcePort;
private string _image;
private int _DestinationPort;
private int _eventcode;
private string _name;
private string _src_ip;
private int _src_port;
private string _dvc;
private int _signature_ID;
private string _dest_ip;
private string _computer;
private string _sourceType;
private int _recordID;
private int _processID;
private DateTime _time;
private int _dest_port;
public string Raw { get { return _raw; } set { _raw = value; } }
public int SourcePort { get { return _sourcePort; } set { _sourcePort = value; } }
public string Image { get { return _image; } set { _image = value; } }
public int DestinationPort { get { return _DestinationPort; } set { _DestinationPort = value; } }
public int Eventcode { get { return _eventcode; } set { _eventcode = value; } }
public string Name { get { return _name; } set { _name = value; } }
public string Src_ip { get { return _src_ip; } set { _src_ip = value; } }
public int Src_port { get { return _src_port; } set { _src_port = value; } }
public string DVC { get { return _dvc; } set { _dvc = value; } }
public int Signature_ID { get { return _signature_ID; } set { _signature_ID = value; } }
public string Dest_ip { get { return _dest_ip; } set { _dest_ip = value; } }
public string Computer { get { return _computer; } set { _computer = value; } }
public string SourceType { get { return _sourceType; } set { _sourceType = value; } }
public int RecordID { get { return _recordID; } set { _recordID = value; } }
public int ProcessID { get { return _processID; } set { _processID = value; } }
public DateTime Indextime { get { return _time; } set { _time = value; } }
public int Dest_port { get { return _dest_port; } set { _dest_port = value; } }
}
This is another class
public class ProcessConnectedIP
{
public Neo4jClient.RelationshipInstance<Pivot> bindto { get; set; }
public Neo4jClient.Node<LogEvent> bindip { get; set; }
public Neo4jClient.RelationshipInstance<Pivot> connectto { get; set; }
public Neo4jClient.Node<LogEvent> connectip { get; set; }
}
This is my neo4jclient query to get the relationship object
public IEnumerable<ProcessConnectedIP> GetConnectedIPs(string nodeName)
{
try
{
var result =
this.client.Cypher.Match("(sourceNode:Process{name:{nameParam}})-[b:Bind_IP]->(bind:IP_Address)-[c:Connect_IP]->(connect:IP_Address)")
.WithParam("nameParam", nodeName)
.Where("b.dest_ip = c.dest_ip")
.AndWhere("c.Image=~{imageParam}")
.WithParam("imageParam", $".*" + nodeName + ".*")
.Return((b, bind, c, connect) => new ProcessConnectedIP
{
bindto = b.As<RelationshipInstance<Creates>>(),
bindip = bind.As<Node<LogEvent>>(),
connectto = c.As<RelationshipInstance<Creates>>(),
connectip = connect.As<Node<LogEvent>>()
})
.Results;
return result;
}catch(Exception ex)
{
Console.WriteLine("GetConnectedIPs: Error Msg: " + ex.Message);
return null;
}
}
This is the method to read the results
public void MyMethod(string name)
{
IEnumerable<ProcessConnectedIP> result = clientDAL.GetConnectedIPs(name);
if(result != null)
{
var results = result.ToList();
Console.WriteLine(results.Count());
foreach (ProcessConnectedIP item in results)
{
Console.WriteLine(item.Data.Src_ip);
Console.WriteLine(item.bindto.StartNodeReference.Id);
Console.WriteLine(item.bindto.EndNodeReference.Id);
Console.WriteLine(item.connectto.StartNodeReference.Id);
Console.WriteLine(item.connectto.EndNodeReference.Id);
Node<LogEvent> ans = item.bindip;
LogEvent log = ans.Data;
Console.WriteLine(log.Name);
Node<LogEvent> ans1 = item.connectip;
LogEvent log1 = ans1.Data;
Console.WriteLine(log1.Name);
}
}
}
Somehow, i'm only able to populate the relationship object with src_ip/src_port/dest_ip/dest_port values. the rest are empty.
Is there any possible reason why? I've played with upper/lower cases on the properties names but it does not seem to work.
This is the section of the graph im working with
This is the relationship properties sample:
_raw: Some XML dataSourcePort: 49767Image: C:\Windows\explorer.exeDestinationPort: 443EventCode: 3Name: Bind
IPsrc_ip: 172.10.10.104dvc: COMPUTER-NAMEsrc_port:
49767signature_id: 3dest_ip: 172.10.10.11Computer:
COMPUTRE-NAME_sourcetype:
XmlWinEventLog:Microsoft-Windows-Sysmon/OperationalRecordID:
13405621ProcessId: 7184_time: 2017-08-28T15:15:39+08:00dest_port: 443

I'm not entirely sure how your Creates class is ever populated, in particular those fields - as your Src_port property doesn't match the src_port in the sample you provided (case wise).
I think it's probably best to go back to a super simple version. Neo4jClient will map your properties to the properties in the Relationship as long as they have the same name (and it is case-sensitive).
So start with a new Creates class (and use auto properties - it'll make your life a lot easier!)
public class Creates
{
public string Computer { get; set; }
}
Run your query with that and see if you get a result, then keep on adding properties that match the name and type you expect to get back (int, string etc)

It seems that i have to give neo4j node/relationship property names in lowercase and without special characters at the start of the property name, in order for the above codes to work.
The graph was not created by me at the start thus i had to work on it with what was given. I had to get the developer who created the graph to create the nodes with lowercases in order for the above to work.

Creating two C# class definitions with a driver to test classes, but not sure why so many errors?

I am new to C# and was asked to create two class definitions (customer and order) using partial code and with the suggested class names, methods, contructors and following an example. I am not sure why I am getting so many errors when I build/debug?
After this is finished, I need to create another program that builds onto this one. Our instructor also asked us not to use validation...
Some of my most common errors are:
expected: ; (in a place in my code where I believe there should not be a semi-colon and
Error "Expected class, delegate, enum, interface, or struct.
Here is my code:
public class clsOrder
{
//declare class variables
protected string cstrDescription;
protected int cintQuantity;
protected decimal cdecPrice;
protected decimal cdecExtendedPrice;
//shared variables
static decimal cdecTotalPrice;
static int cintTotalCount;
//declare constructors
public clsOrder();
}
public clsOrde r(string strDescription,
int intQuantity, decimal decPrice)
}
//declare property methods
{
this.Description = string strDescription;
this.Quantity = int intQuantity;
this.Price = decimal decPrice;
//declare read-only properties
public decimal ExtendedPrice
}
public string Description
{
get
{
return strDescription;
}
set
{
strDescription = value;
}
}
public int Quantity
{
get
{
return intQuantity;
}
set
{
intQuantity = value;
}
}
public decimal Price
{
get
{
return decPrice;
}
set
{
decPrice = value;
}
}
get
{
return cdecExtendedPrice;
}
}
//declare Shared (static) ReadOnly Properites
public static decimal TotalPrice
{
get
{
return cdecTotalPrice;
}
}
public static int TotalCount
{
get
{
return cintTotalCount;
}
}
//declare supporting methods
public void calcExtendedPrice()
{
cdecExtendedPrice = cintQuantity * cdecPrice;
}
public void accumulateTotals()
{
cdecTotalPrice += cdecExtendedPrice;
cintTotalCount += 1;
}
public static void resetTotals()
{
cdecTotalPrice = 0;
cintTotalCount = 0;
}
}//end of Class
}//end of namespace
And
public class clsCustomer
{
//declare class variables
private string cstrName;
private string cstrStreet;
private string cstrCity;
private string cstrState;
private string cstrZip;
//declare constructors
public class clsCustomer()
}
public clsCustomer(string strName,
string strStreet, string strCity,
string strState, string strZip)
}
//declare property methods
{
this.Name = cstrName;
this.Street = cstrStreet;
this.City = cstrCity;
this.State = cstrState;
this.Zip = cstrZip;
}
public string Name
{
get
{
return cstrName;
}
set
{
cstrName = value;
}
}
public string Street
{
get
{
return cstrStreet;
}
set
{
cstrStreet = value;
}
}
public string City
{
get
{
return cstrCity;
}
set
{
cstrCity = value;
}
}
public string State
{
get
{
return cstrState;
}
set
{
cstrState = value;
}
}
public string Zip
{
get
{
return cstrZip;
}
set
{
cstringZip = value;
}
}
Any help would be very much appreciated, thank you.

Convert two classes in VB.net to C# but get object reference error

I have converted the following two classes to c# from vb.net, but get a reference error. Can someone please help or explain why it does not work in c# but does in vb.net?
Member class:
public class Member
{
#region "Fields"
private string fPiecemark;
private string fMemberType;
private string fSize;
private string fTotalWeight;
private int fSheetKey;
private string fDescription;
private string fStructType;
#endregion
private string fMemberSheetIndex;
#region "Constructors"
//Default class Constructor
public Member()
{
fPiecemark = string.Empty;
fMemberType = string.Empty;
fSize = string.Empty;
fTotalWeight = string.Empty;
fSheetKey = 0;
fStructType = string.Empty;
}
public Member(string Piecemark, string MemberType, string Description, string Size, string TotalWeight, string StructType, string MemberSheetIndex, int SheetID)
{
this.Piecemark = Piecemark;
this.MemberType = MemberType;
this.Description = Description;
this.Size = Size;
this.TotalWeight = TotalWeight;
this.StructType = StructType;
this.MemberSheetIndex = MemberSheetIndex;
this.SheetKey = SheetID;
if (!MbrSheet.mSheet.ContainsKey(SheetID))
{
MbrSheet.mSheet.Add(SheetID, new MbrSheet(SheetID));
}
MbrSheet.mSheets[SheetID].Members.Add(this);
}
#endregion
#region "Properties"
public string Piecemark
{
get { return fPiecemark; }
set { fPiecemark = value; }
}
public string MemberType
{
get { return fMemberType; }
set { fMemberType = value; }
}
public string TotalWeight
{
get { return fTotalWeight; }
set { fTotalWeight = value; }
}
public string Size
{
get { return fSize; }
set { fSize = value; }
}
public int SheetKey
{
get { return fSheetKey; }
set { fSheetKey = value; }
}
public string Description
{
get { return fDescription; }
set { fDescription = value; }
}
public string StructType
{
get { return fStructType; }
set { fStructType = value; }
}
public string MemberSheetIndex
{
get { return fMemberSheetIndex; }
set { fMemberSheetIndex = value; }
}
#endregion
}
MbrSheet class:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Globalization;
public class MbrSheet
{
public static Dictionary<int, MbrSheet> mSheets = new Dictionary<int, MbrSheet>();
public int mSheet { get; set; }
public List<Member> Members { get; set; }
public MbrSheet(int MbrSheet)
{
Members = new List<Member>();
this.mSheet = MbrSheet;
}
public static decimal WeightByType(string MemberType)
{
var subset = mSheets.Where(kvp => kvp.Value.Members.Where(m => m.MemberType == MemberType).Count() > 0);
decimal wbt = 0;
wbt += mSheets
.Where(kvp => kvp.Value.Members.Where(m => m.MemberType == MemberType).Count() > 0)
.Sum(kvp => kvp.Value.Members.Sum(m => Convert.ToDecimal(m.TotalWeight, CultureInfo.InvariantCulture)));
return wbt;
}
}
I get error but don't know why
An object reference is required for the non-static field, method, or property for MbrSheet.mSheet, but both worked in VB.net
if (!MbrSheet.mSheet.ContainsKey(SheetID)) // Error on !MbrSheet.mSheet
{
MbrSheet.mSheet.Add(SheetID, new MbrSheet(SheetID)); // Error on MbrSheet.mSheet
}

I think you should use this:
if (!MbrSheet.mSheets.ContainsKey(SheetID))
{
MbrSheet.mSheets.Add(SheetID, new MbrSheet(SheetID));
}
Pay attention to mSheets you are using mSheet.
You can also use tools to convert codes:
http://www.developerfusion.com/tools/convert/csharp-to-vb/
http://codeconverter.sharpdevelop.net/SnippetConverter.aspx

c# BindingList read-only error

I keep trying to look for the possible cause of the problem but I cant seem to find it:
Error:
System.NotSupportedException: Collection is read-only. at
System.ThrowHelper.ThrowNotSupportedException(ExceptionResource
resource) at System.Collections.ObjectModel.Collection`1.Add(T
item) at
WindowsFormsApplication1.Form1.Btn_CSVSEATINGPLAN_Click(Object sender,
EventArgs e) in C:\Users\aRJiJon\Documents\Visual Studio
2010\Projects\WindowsFormsApplication_1\WindowsFormsApplication1\Form1.cs:line
72
this.dataGridView1.DefaultCellStyle.Font = new Font("Tahoma", 11);
bindingCSVSP.DataSource = CSV_Seating_Plan;
bindingCSVSP.AllowNew = true;
CSV_Seating_Plan.AllowNew = true;
CSV_Seating_Plan.AllowRemove = true;
CSV_Seating_Plan.RaiseListChangedEvents = true;
CSV_Seating_Plan.AllowEdit = true;
this.dataGridView1.DataSource = bindingCSVSP;
this.btn_Process_SP.Enabled = true;
CSV_Seating_Plan.Add(new csv_SeatingPlan());
public string examperiod;
[FieldConverter(ConverterKind.Date, "dd/mm/yyyy")]
public DateTime date_Exam;
public string time;
public string exam_Code;
public string id_Student;
public string name_Student;
public string candidatenum_Student;
public string seat_num;
public string _WSS_EXEC;
public string exam_loc;
#region getsetmethods.
public string EXAMPERIOD
{ get { return this.examperiod; } }
public DateTime DATE_TIME
{ get { return this.date_Exam; } }
public string TIME
{ get { return this.time; } }
public string EXAM_CODE
{ get { return this.exam_Code; } }
public string ID_STUDENT
{ get { return this.id_Student; } }
public string NAME_STUDENT
{ get { return this.name_Student; } }
public string CANDIDATE_NUMBER
{ get { return this.candidatenum_Student; } }
public string SEAT_NUM
{ get { return this.seat_num; } }
public string WSS_EXEC
{ get { return this._WSS_EXEC; } }
public string EXAM_LOC
{ get { return this.exam_loc; } }
#endregion
public csv_SeatingPlan()
{
}
Can anyone tell me what I'm missing?

This means that the underlying implementation of IList for you generic collection class is returning true for the IsReadOnly property.