When accessing the property using the getter i'm getting a NULL. I've changed it to public to test if everything else is working and yeah nothing else is wrong.
HTProvince Class
public string provinceCode;
public string ProvinceCode
{
get; set;
}
Form
public Form1()
{
//HTGetProvinces() returns a list of provinces
InitializeComponent();
List<HTProvince> provinceList =
HTProvince.HTGetProvinces();
foreach (HTProvince x in provinceList)
{
//Works. Adds items the province code property of for each item to my list
provincesListBox.Items.Add(x.provinceCode);
//throws null exception. Doesn't work
provincesListBox.Items.Add(x.ProvinceCode);
}
}
That is a bad practice. You have to make your field 'provinceCode' to private
private string provinceCode;
Your property has to be only public
Which can only be access.
public string ProvinceCode
{
get
{
return provinceCode;
}
set
{
provinceCode = value;
}
}
public Form1()
{
//HTGetProvinces() returns a list of provinces
InitializeComponent();
List<HTProvince> provinceList =
HTProvince.HTGetProvinces();
foreach (HTProvince x in provinceList)
{
//Works. Adds items the province code property of for each item to my list
provincesListBox.Items.Add(x.ProvinceCode);
}
}
That is right behaviour, you have not return any value for this property or set value so it is null.
public string ProvinceCode
{
get; set;
}
if you want to return the provinceCode
private string provinceCode;
public string ProvinceCode
{
get
{
return provinceCode;
}
set
{
provinceCode = value;
}
}
If you want to have some default value if ProvinceCode is not set you could use lazy loading:
private string _provinceCode;
public string ProvinceCode
{
get
{
if(string.IsNullOrEmpty(_provinceCode)) {
_provinceCode = "CODE";
}
return _provinceCode;
}
set
{
_provinceCode = value;
}
}
This is auto-properties introduced in C# 3.0 and later
Change the property to:
private string provinceCode { get; set; }
Instead of a separate method:
public string ProvinceCode
{
get; set;
}
Related
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.
I want to populate a combobox with two different objects using an interface. This is what I currently got. This works but now I would like to have a display member and value member for each object, how would I do so?
In Controller.cs
public List<IMusic> Populate()
{
List<IMusic> newList = new List<IMusic>();
foreach(Track t in tr.GetAllTracks()){
newList.Add(t);
}
foreach (Artist a in ar.GetAllArtists())
{
newList.Add(a);
}
return newList;
}
IMusic.cs
interface IMusic
{
}
The combobox with DataSource:
cBMainScreen_Search.DataSource = controller.Populate();
GetAllTracks() :
public List<Track> GetAllTracks()
{
return db.Track.ToList();
}
GetAllArtists() :
public List<Artist> GetAllArtists()
{
return db.Artist.ToList();
}
Just setup some properties in your interface:
interface IMusic
{
string Display { get; set; }
string Value { get; set; }
}
Then in your Track class (which should implement IMusic):
public string Display
{
get
{
return this.TrackName;
}
set
{
this.TrackName= value;
}
}
public string Value
{
get
{
return this.TrackID;
}
set
{
this.TrackID= value;
}
}
And in your Artist class (also implements IMusic):
public string Display
{
get
{
return this.ArtistName;
}
set
{
this.ArtistName= value;
}
}
public string Value
{
get
{
return this.AritstID;
}
set
{
this.AritstID= value;
}
}
please tell me best way to implement many duplicate INotifyPropertyChanged.
I have a MainClass that has 10 children, every child has six field and every field must fired property change when own value changed.
this my code but not work:
public class BaseModel
{
public string S1 { get; set; }
public string S2 { get; set; }
public string S3 { get; set; }
public string S4 { get; set; }
public string S5 { get; set; }
public string S6 { get; set; }
}
and I use a class named ViewModelBase to implement INotifyPropertyChanged.
in second step use a class to implement duplicate INotifyPropertyChanged:
public class ImplementBaseModel : ViewModelBase
{
private readonly BaseModel _baseModel;
public ImplementBaseModel()
{
_baseModel = new BaseModel();
}
public string S1
{
get { return _baseModel.S1; }
set
{
if (_baseModel.S1 == value)
return;
_baseModel.S1 = value;
base.OnPropertyChanged("S1");
}
}
public string S2
{
get { return _baseModel.S2; }
set
{
if (_baseModel.S2 == value)
return;
_baseModel.S1 = value;
base.OnPropertyChanged("S2");
}
}
// other code...
}
then a model has 10 of this class:
public class MidClass
{
public ImplementBaseModel ImplementBaseModel1 { get; set; }
public ImplementBaseModel ImplementBaseModel2 { get; set; }
// other field
public ImplementBaseModel ImplementBaseModel10 { get; set; }
public MidClass()
{
ImplementBaseModel1 = new ImplementBaseModel();
ImplementBaseModel2 = new ImplementBaseModel();
// ....
ImplementBaseModel10 = new ImplementBaseModel();
}
}
OK finish code! now please tell me why some property not fired when value change? is a best way to implement this code?
In your setters, you never actually set the value. Use:
public string S1
{
get { return _baseModel.S1; }
set
{
if (_baseModel.S1 == value)
return;
baseModel.S1 = value;
OnPropertyChanged("S1");
}
}
Note that I removed the base from OnPropertyChanged. It isn't normal to invoke the PropertyChanged event in this way.
All NotifyPropertyChanged does is cause every binding to perform a "get" on their bound property. If the backing field is never updated, they will just get the same data.
as a shortcut, you could also create a local method like
bool UpdateAndRaiseIfNecessary( ref string baseValue, string newValue, [CallerMemberName] string propertyName = null)
{
if (baseValue != newValue)
{
baseValue = newValue;
OnPropertyChanged( propertyName );
return true;
}
return false;
}
and then all of the setters would be like this:
set
{
this.UpdateAndRaiseIfNecessary( ref _baseModel.S1, value );
}
Please help, I'm confused I do not know why the error logs
System.StackOverflowException was unhandled.
I keep getting an error on set LekID.
How would I that fix?
Here is the code:
public Lager(long lekID, string lek, string proizvojdac, int kolicina, double cena)
{
LekID = lekID;
Lek = lek;
Proizvodjac = proizvojdac;
Kolicina = kolicina;
Cena = cena;
}
public long LekID
{
get { return LekID; }
set { LekID = value; }
}
public string Lek
{
get { return Lek; }
set { Lek = value; }
}
public string Proizvodjac
{
get { return Proizvodjac; }
set { Proizvodjac = value; }
}
public int Kolicina
{
get { return Kolicina; }
set { Kolicina = value; }
}
public double Cena
{
get { return Cena; }
set { Cena = value; }
}
public long LekID
{
get { return LekID; }
set { LekID = value; }
}
This (and the other properties) cause a StackOverflowException, since you are assigning value to LekID over and over again.
You should add a field to the property and store the value there:
private long _lekID;
public long LekID
{
get { return _lekID; }
set { _lekID = value; }
}
You should give different names to your private variables and to your properties. Otherwise, your property is calling itself when you access it.
Example:
long _lekID;
public long LekID
{
get { return _lekID; }
set { _lekID = value; }
}
Or simply:
public long LekID { get; set; }
The properties are calling themself. Try changing your properties like this:
public string Lek
{
get;
set;
}
You're calling the Lek property recursively in both the setter and the getter
Either introduce a backing field:
private string lek;
public string Lek
{
get { return this.lek; }
set { this.lek = value; }
}
or use an Automatic Property:
public string Lek
{
get; set;
}
Marking this community wiki as it is only an aside, but none of this would have happened if you'd been sufficiently lazy (that is often a virtue in programming, not a vice):
public long LekID {get;set;}
public string Lek {get;set;}
public string Proizvodjac {get;set;}
public int Kolicina {get;set;}
public double Cena {get;set;}
less typing; no errors; and you've correctly exposed the API as properties so you can add validation / side-effects later if you need, and it'll work with binding APIs (which don't usually love fields).
Try using code snippet like prop/ propfull,
the snippets will create the properties code automaticly
This is the working class:
namespace Lite
{
public class Spec
{
public int ID { get; set; }
public string Name { get; set; }
public string FriendlyName { get; set; }
public int CategoryID { get; set; }
public int Width { get; set; }
public int Height { get; set; }
public string UOM { get; set; }
public int Pagination { get; set; }
public int ColoursFront { get; set; }
public int ColoursBack { get; set; }
public string Material { get; set; }
public int GSM { get; set; }
public string GSMUOM { get; set; }
public bool Seal { get; set; }
public Spec(int ID)
{
using (CrystalCommon.MainContext db = new CrystalCommon.MainContext())
{
var q = (from c in db.tblSpecifications where c.id == ID select c).SingleOrDefault();
if (q != null)
loadByRec(q);
}
}
public Spec(CrystalCommon.tblSpecification Rec)
{
loadByRec(Rec);
}
public void loadByRec(CrystalCommon.tblSpecification Rec)
{
this.ID = Rec.id;
this.Name = Rec.Title;
this.Width = Convert.ToInt32(Rec.FinishedSizeW.Value);
this.Height = Convert.ToInt32(Rec.FinishedSizeL.Value);
this.UOM = Rec.FlatSizeUOM;
this.Pagination = Rec.TxtPagination.Value;
this.ColoursFront = Convert.ToInt32(Rec.TxtColsF.Value);
this.ColoursBack = Convert.ToInt32(Rec.TxtColsB.Value);
this.Material = Rec.TxtMaterial;
this.GSM = Rec.TxtGSM.Value;
this.GSMUOM = Rec.txtGsmUnit;
this.Seal = Rec.TxtSeal.Value == 1;
}
public string displayDimensions()
{
return Width + " x " + Height + " " + UOM;
}
}
}
Then I try and modify the Name getter and setter:
namespace Lite
{
public class Spec
{
public int ID { get; set; }
// User friendly name if available otherwise fall back on spec name
public string Name { get {
if (null != FriendlyName)
return FriendlyName;
else
return Name;
}
set
{
Name = value;
}
}
public string FriendlyName { get; set; }
public int CategoryID { get; set; }
public int Width { get; set; }
public int Height { get; set; }
public string UOM { get; set; }
public int Pagination { get; set; }
public int ColoursFront { get; set; }
public int ColoursBack { get; set; }
public string Material { get; set; }
public int GSM { get; set; }
public string GSMUOM { get; set; }
public bool Seal { get; set; }
public Spec(int ID)
{
using (CrystalCommon.MainContext db = new CrystalCommon.MainContext())
{
var q = (from c in db.tblSpecifications where c.id == ID select c).SingleOrDefault();
if (q != null)
loadByRec(q);
}
}
public Spec(CrystalCommon.tblSpecification Rec)
{
loadByRec(Rec);
}
public void loadByRec(CrystalCommon.tblSpecification Rec)
{
this.ID = Rec.id;
this.Name = Rec.Title;
this.Width = Convert.ToInt32(Rec.FinishedSizeW.Value);
this.Height = Convert.ToInt32(Rec.FinishedSizeL.Value);
this.UOM = Rec.FlatSizeUOM;
this.Pagination = Rec.TxtPagination.Value;
this.ColoursFront = Convert.ToInt32(Rec.TxtColsF.Value);
this.ColoursBack = Convert.ToInt32(Rec.TxtColsB.Value);
this.Material = Rec.TxtMaterial;
this.GSM = Rec.TxtGSM.Value;
this.GSMUOM = Rec.txtGsmUnit;
this.Seal = Rec.TxtSeal.Value == 1;
}
public string displayDimensions()
{
return Width + " x " + Height + " " + UOM;
}
}
}
On my computer this compiles fine, but the server seems to crash when it runs. (First version works fine). My colleague compiled it on his machine and it threw a "Stack overflow error" apparently, but he's not around for me to get specifics on that right now.
Am I applying the getter correctly here?
This is an endless loop:
public string Name { get {
...
set
{
Name = value;
}
}
The setter will call itself repeatedly until you get the Stack overflow exception.
usually you have a backing variable, so it ends up like this
private string name;
public string Name {
get {
if (null != FriendlyName)
return FriendlyName;
else
return name;
}
set {
name = value;
}
}
Your set is referencing the property itself, and your get is referencing the property itself, both of these will cause a potentially endless loop leading to a StackOverflowException (no more stack space to push the current call into). You need to use a backing field:
private string _name;
public string Name
{
get
{
if (null != FriendlyName)
return FriendlyName;
else
return _name;
}
set
{
_name = value;
}
}
It looks as though you tried to turn an auto-property into a manual one. Auto-properties (public string Name { get; set; }) work because the compiler will create the backing field itself.
As a learning exercise, if you step through with the debugger and step into return Name or Name = value you will see first hand the code going back into the property you are already in.
This is much better.
string _name = "";
public string Name
{
get { return FriendlyName ?? _name; }
set { _name = value; }
}
One of your properties gets and sets itself, see:
public string Name
{
get {
if (null != FriendlyName)
return FriendlyName;
else
return Name; //<-- StackOverflow
}
set
{
Name = value; //<-- StackOverflow
}
}
You have a getter for Name, that calls the property Name, which will call the getter for Name, etc. You need a private field to back the property, and you need to access that backing field in your getter instead.
public string Name { get {
if (null != FriendlyName)
return FriendlyName;
else
return Name;
}
set
{
Name = value;
}
}
Name in the get/set refers to the property. You will need to define a backing field and use that.
If FriendlyName is null then the Name getter attempts to get the value from the Name getter - i.e. it loops. This is what causes the stack overflow.
No you should use a backing field. The error is in the else
public string Name { get {
if (null != FriendlyName)
return FriendlyName;
else
return Name;//error, you're calling the property getter again.
}