C# Namespace communication - c#

may I ask (as a novice) how do I call a method of a namespace, from another? Thank you for setting up an example if possible..
For example: (1) how do I set the properties of the MY_PRIMARY class to use them and (2) how do I call the AddNumbers method while in the MY_SECONDARY namespace? Thank you..
using.. etc
namespace MY_PRIMARY
{
public partial class SomethingHere
{
public Boolean holiday { get; set; } = false;
public int age { get; set; } = 18;
//etc...
}
class Program
{
private static void Main()
{
// some code here.. and..
public int AddNumbers(int number1, int number2)
{
int result = number1 + number2;
return result;
}
}
};
namespace MY_SECONDARY
{
public partial class SomethingElseHere
{
public Boolean holiday { get; set; } = false;
public int age { get; set; } = 18;
//etc...
}
class Program
{
static void Main()
{
// some code here..
}
// and..
Program outer = new Program();
outer.AddNumbers(3, 18); // <--- this is failing..
}
}
;

Namespaces are meant to group objects semantically. I'm kind of confused why you have 2 program classes. It would make more sense to have one class library, and one program. Anyway...
Suppose you have an Object1 in namespace Program.First,
And an Object2 in Program.Second
Object2 has a method named someMethod.
What you would do to call this method is
a) either add "using Program.Second", on you first class.
b) make an instance of Program.Second.Object2, and call the method on that.
https://www.programiz.com/csharp-programming/namespaces
So suppose you want to make an object of Program() do this:
using System;
namespace MY_PRIMARY
{
public partial class SomethingHere
{
public Boolean holiday { get; set; } = false;
public int age { get; set; } = 18;
//etc...
}
public class Program
{
public int AddNumbers(int number1, int number2)
{
int result = number1 + number2;
return result;
}
}
}
namespace MY_SECONDARY
{
public partial class SomethingElseHere
{
public Boolean holiday { get; set; } = false;
public int age { get; set; } = 18;
//etc...
}
class Program
{
static void Main()
{
MY_PRIMARY.Program outer = new MY_PRIMARY.Program();
outer.AddNumbers(3, 18);
}
}
}
(EDIT) updated my answer, i copied your code and saw that your namespaces were not closed off, therefor, you had nested namespaces, and classes in there. plus, some of the code was directly in your class instead of in a function.
Also, don't define 2 Main() methods, that's the entrypoint of the application.

...A little modification in POSITIONS of functions and classes... please, see:
using Alias = MY_PRIMARY.Program;
namespace MY_PRIMARY
{
public partial class SomethingHere
{
public Boolean holiday { get; set; } = false;
public int age { get; set; } = 18;
//etc...
}
public class Program
{
private static void Main()
{
// some code here.. and..
}
public int AddNumbers(int number1, int number2)
{
int result = number1 + number2;
return result;
}
};
namespace MY_SECONDARY
{
public partial class SomethingElseHere
{
public Boolean holiday { get; set; } = false;
public int age { get; set; } = 18;
//etc...
}
class Program
{
static void Main()
{
// some code here..
// and..
Alias outer = new Alias();
outer.AddNumbers(3, 18); // <--- OKAY...
}
}
}
}
See more:
Using namespaces (C# Programming Guide)

Related

How to create a structure with embedded fields?

I am looking for information about that in the internet but with no success. The goal is to realize a sort of dataset of 10 subject (sub_1, sub_2... sub_10), each of them has done 3 kind of activities (walk, run, jump) for three time each (trial_1... trial_3) with relative scores. I would like to access these information like:
variable = dataset.sub_1.jump.trial_2.score;
or, at least:
variable = dataset.sub[0].task[2].trial[1].score;
So, the structure would be a tree structure. Until now I only realized a structure with "parallel fields":
struct dataset
{
public string[] sub; // 1 to 10 subjects
public string[] task; // 1 to 3 tasks
public string[] trial; // 1 to 3 trials
public int score; // the score of the above combination
}
Any idea?
This problem can be solved in many ways.
My solution has one drawback, there is no check if user exceeded Score arrays capacity.
I guess database tag has nothing to do with this question
using System;
using System.Linq;
namespace ConsoleApp
{
public abstract class Task
{
public string Name { get; set; }
public int TotalScore { get { return Score.Sum(); } }
public int[] Score { get; set; } = new int[3];
}
public class Walk : Task { }
public class Run : Task { }
public class Jump : Task { }
public class Subject
{
public Walk Walk { get; set; } = new();
public Run Run { get; set; } = new();
public Jump Jump { get; set; } = new();
public int TotalScore { get { return Walk.TotalScore + Run.TotalScore + Jump.TotalScore; }}
}
class Program
{
static void Main(string[] args)
{
var subject = new Subject();
// Adding score to specific trials
subject.Run.Score[0] = 50;
subject.Run.Score[1] = 40;
subject.Run.Score[2] = 60;
subject.Jump.Score[0] = 40;
subject.Jump.Score[1] = 80;
subject.Jump.Score[2] = 100;
// Output score of 1. trial for Walk task
Console.WriteLine(subject.Walk.Score[0]);
// Output total score as a sum of all trials for Jump task
Console.WriteLine(subject.Jump.TotalScore);
// Output total score as a sum of all trials in all tasks
Console.WriteLine(subject.TotalScore);
// ERROR CASE: this will be exception
subject.Jump.Score[3] = 100;
}
}
}
using System;
using System.Collections.Generic;
namespace ConsoleApp
{
public class Trial
{
public Trial(int score)
{
Score = score;
}
public int Score { get; set; }
}
public class Task
{
public List<Trial> Trials { get; } = new List<Trial>();
}
public class Subject
{
public Dictionary<string, Task> Tasks { get; } = new Dictionary<string, Task>();
public Subject()
{
Tasks.Add("walk", new Task());
Tasks.Add("run", new Task());
Tasks.Add("jump", new Task());
}
}
class Program
{
static void Main(string[] args)
{
Subject player1 = new Subject();
player1.Tasks["run"].Trials.Add(new Trial(score: 3));
Console.WriteLine(player1.Tasks["run"].Trials[0].Score);
}
}
}
Maybe a class for everything is too much, but maybe you want to add a description property for tasks one day or a timestamp for the trial. Then it's ok.
public class Subject
{
private Dictionary<string,Activity> _activities { get; }= new Dictionary<string, Activity>();
public Activity this[string activity]
{
get
{
if (!_activities.Keys.Contains(activity))
_activities[activity] = new Activity();
return _activities[activity];
}
set
{
_activities[activity] = value;
}
}
public int Score => _activities.Values.Sum(x => x.Score);
}
public class Activity
{
private Dictionary<int, Trial> _trials { get; } = new Dictionary<int, Trial>();
public Trial this[int trial]
{
get
{
if (!_trials.Keys.Contains(trial))
_trials[trial] = new Trial();
return _trials[trial];
}
set
{
_trials[trial] = value;
}
}
public int Score => _trials.Values.Sum(x => x.Score);
}
public class Trial
{
public int Score { get; set; }
}
public class Answer
{
public void DoSomething()
{
Subject Mindy = new Subject();
Mindy["curling"][1].Score = 5;
Mindy["bowling"][1].Score = 290;
Console.WriteLine(Mindy.Score);
}
}
This is what I would guess you think you need... but from your question I think you're still new to C# and might want to rethink your concept. It looks like a very database-oriented way of looking at the problem, so maybe you might want to take a look at dapper to more closely match your database.
Also, avoid using the classname Task, this can imo only cause confusion if you ever start using multithreading (System.Threading.Task is a .NET framework component)

instance access to class members of inherited abstract

This is theory Thursday I guess.
Shouldn't Main() have access to _XLocal & _YLocal?
using System;
namespace HelloGoodbyeOperator {
public abstract class HGOperator {
public string _greeting { get; set; }
public bool _x { get; internal set; }
public bool _y { get; internal set; }
public static implicit operator HGOperator(bool mode) {
object ret = new object();
if (mode)
ret = new HGOperator_Hello { _greeting = "hello", _XLocal = 10 };
else
ret = new HGOperator_Goodbye { _greeting = "goodbye", _YLocal = 20 };
return (HGOperator)ret;
}
}
public class HGOperator_Hello : HGOperator {
public int _XLocal { get; set; }
public HGOperator_Hello() { _x = true; Console.WriteLine("HGOperator_Hello //" + _XLocal.ToString() + "\\\\"); }
}
public class HGOperator_Goodbye : HGOperator {
public int _YLocal { get; set; }
public HGOperator_Goodbye() { _y = false; Console.WriteLine("HGOperator_Goodbye //", _YLocal, "\\\\"); }
}
class Program {
static void Main(string[] args) {
HGOperator hg = true;
Console.WriteLine(hg._greeting);
test(hg);
Console.WriteLine("");
hg = false;
Console.WriteLine(hg._greeting);
test(hg);
Console.ReadKey();
}
static void test(HGOperator hg) {
if (hg is HGOperator_Hello) {
Console.WriteLine(hg._x);
//Console.WriteLine(hg._XLocal);
} else {
Console.WriteLine(hg._y);
//Console.WriteLine(hg._YLocal);
}
}
}
}
Here is the output
HGOperator_Hello //0\
hello
True
HGOperator_Goodbye //
goodbye
False
I can understand how trying to access hg._YLocal of a HGOperator_Hello type would be a nightmare & vise-versa. But would still think I could get to the respective members with caution.
Also and I will bet this is realted. The two concrete constructors do not have a value for _XLocal & _YLocal on the Console.Writeline()s. Without the .ToString() just a "" is printed. Why not?
Thanks.
The issue is that the compiler doesn't know that hg is a derived type of HGOperator_Hello or HGOperator_Goodbye. So inside your if you need to create another variable and cast it:
if (hg is HGOperator_Hello)
{
var helloHg = (HGOperator_Hello)hg;
Console.WriteLine(helloHg._x);
Console.WriteLine(helloHg._XLocal);
}
else
{
var goodbyeHg = (HGOperator_Goodbye)hg;
Console.WriteLine(goodbyeHg._y);
Console.WriteLine(goodbyeHg._YLocal);
}

Categorizing class functions in groups

Imagine a class as follows.. It's a class provided to me to work with.. I cannot change its source..
public class MyClass
{
object _Object { get; set; }
public void FuncA1() { _Object = new object(); }
public void FuncA2() { _Object = new List<object>(); }
public int FuncB1() { _Object = 0; return 0; }
public int FuncB2() { _Object = 123; return 123; }
public string FuncC1() { _Object = null; return null; }
public string FuncC2() { _Object = "Hello"; return "Hello"; }
}
Im trying to create a wrapper for this class, such that I can group its many functions into categories..
MyWrapper.Voids.FuncA1();
MyWrapper.Voids.FuncA2();
MyWrapper.Integers.FuncB1();
MyWrapper.Integers.FuncB2();
MyWrapper.Strings.FuncC1();
MyWrapper.Strings.FuncC2();
The only solution I can think of for this scenario is to design the wrapper like this:
public class MyWrapper
{
MyClass _Instance { get; set; }
public _Void Voids { get; private set; }
public _Integer Integers { get; private set; }
public _String Strings { get; private set; }
public class _Void
{
MyWrapper _Parent { get; set; }
public void FuncA1() { _Parent._Instance.FuncA1(); }
public int FuncA2() { return _Parent._Instance.FuncA2(); }
}
public class _Integer
{
...
}
public class _String
{
...
}
public MyWrapper()
{
_Instance = new MyClass();
Voids = new _Voids(this);
Integers = new _Integer(this);
Strings = new _String(this);
}
}
This solution works, but has a number of problems:
- The inner classes are forced to be public, which allows them to be instantiated by the user..
- I am forced to maintain a reference of the parent object in the child classes..
Is there a better way of doing this?
EDIT: The code posted initially was a bit confusing, in the sense that it was diverting attention away from the core issue and more into the issues of whether a function would cause exceptions or not if they all work on the same object..
NOTE: This is not actual code.. I hacked together this example to show what I'm trying to do.. CREATE A WRAPPER AROUND AN OBJECT (I cannot change the original object's code) AND GROUP FUNCTIONS INTO CATEGORIES..
FINAL EDIT: following suggestion by Juharr.. here's what ive done to accomplish what i wanted.. for the betterment of others..
public interface IVoid
{
void FuncA1();
void FuncA2();
}
public interface IInteger
{
int FuncB1();
int FuncB2();
}
public class MyWrapper
{
public MyClass Instance { get; private set; }
public IVoid Voids { get; private set; }
public IInteger Integers { get; private set; }
private abstract class MyBase
{
protected MyWrapper Parent { get; set; }
protected MyClass Instance { get { return Parent.Instance; } }
public MyBase(MyWrapper oParent) { Parent = oParent; }
}
private class MyVoid : MyBase, IVoid
{
public MyVoids (MyWrapper oParent) : base(oParent) { }
public void FuncA1() { Instance.FuncA1(); }
public void FuncA2() { Instance.FuncA2(); }
}
private class MyInteger : MyBase, IInteger
{
public MyInteger (MyWrapper oParent) : base(oParent) { }
public int FuncB1() { return Instance.FuncB1(); }
public int FuncB2() { return Instance.FuncB2(); }
}
public MyWrapper()
{
Instance = new MyClass();
Voids = new MyVoid(this);
Integers = new MyInteger(this);
}
}
You could write public interfaces instead. Then your inner classes don't have to be public. So something like this.
public interface IIntger
{
void Set(int iValue);
int Get();
}
public class MyWrapper
{
MyClass _Instance { get; set; }
public IInteger Integer { get; private set; }
private class _Integer : IInteger
{
MyWrapper _Parent { get; set; }
public void Set(int iValue) { _Parent._Instance.IntegerSet(iValue); }
public int Get() { return _Parent._Instance.IntegerGet(); }
}
public MyWrapper()
{
_Instance = new MyClass();
Integer = new _Integer(this);
}
}
EDIT:
To answer the second part of your question you will either need the reference to the parent class or a reference to the class you are wrapping. So you could have this instead.
public class MyWrapper
{
public IInteger Integer { get; private set; }
private class _Integer : IInteger
{
MyClass _Instance { get; set; }
public _Integer(MyClass myClass) { _Instance = myClass; }
public void Set(int iValue) { _Instance.IntegerSet(iValue); }
public int Get() { return _Instance.IntegerGet(); }
}
public MyWrapper(MyClass instance)
{
Integer = new _Integer(instance);
}
}

C# Avoid Multiple SWITCH Statements .net

Please excuse bursts of stupidity as I learn the intricacies of C# / .NET
Say I have three classes with multiple static properties (more than three but for arguments sake..)
CLASS FOO
public static A
{
get / set A;
}
public static B
{
get / set B;
}
public static C
{
get / set C;
}
CLASS BAR
{
get / set A;
}
public static B
{
get / set B;
}
public static C
{
get / set C;
}
CLASS YOO
{
get / set A;
}
public static B
{
get / set B;
}
public static C
{
get / set C;
}
And from another class I need to update one or several static properties in each class multiple times... How do I keep from writing multiple SWITCH statments like this...
public void updateVarx(string class, string varx)
{
string y = 'class'
SWITCH (y)
{
case FOO:
FOO.A = Varx;
break;
case BAR:
BAR.A = Varx;
break;
case YOO:
YOO.A = Varx;
break;
}
}
And then another one when I want to update B varY:
public void updateVary(string class, string vary)
{
string y = 'class'
SWITCH (y)
{
case FOO:
FOO.B = Vary;
break;
case BAR:
BAR.B = Vary;
break;
case YOO:
YOO.B = Vary;
break;
}
}
Since you are learning .net/c#, I guess i should warn you, using static properties is probably not the way to go in object oriented programming.
Static is global state and is dangerous. If you end up using multi-threaded code, you have to be super careful. If you need only one instance, just instantiate one, but don't go creating static properties on a class, unless you have a pretty good reason to add them (And I can't think of any right now).
In fact, in well designed, object oriented code you sould probably not have many if, switch, getters or setters either.
Let's say you need different behaviors on your classes, you can do it this way.
Interface ISecurity {
void UpdateVarX(int value);
void UpdateVarY(int value);
int GetValueX();
int GetValueX();
}
class Foo:ISecurity {
// Implement methods of the interface
}
class Bar:ISecurity {
// Implement methods of the interface
}
class Yoo:ISecurity {
// Implement methods of the interface
}
// This class is the class that uses your other classes
class Consumer
{
private ISecurity sec;
public Consumer(ISecurity sec) {
sec.UpdateVarX(25);
}
}
Or if as in your example, all your static classes have the same properties:
public class Settings {
public int A {get; set;}
public int B {get; set;}
public int C {get; set;}
}
public class NeedsToUseOtherClass {
public NeedsToUseOtherClass() {
Settings foo = new Settings();
Settings bar = new Settings();
Settings yoo = new Settings();
foo.setA(25);
}
}
Maybe I am not understanding the problem but if all your classes have the same exact properties then you can just pass the object (FOO, BAR, or YOO) into UpdateVarx or UpdateVary methods and just implement an interface? Something along these lines:
public class FOO : IHasStatus
{
public A
{
get / set A;
}
public B
{
get / set B;
}
public C
{
get / set C;
}
}
public void updateVarx(IHasStatus someObject, string varx)
{
someObject.A = varx;
}
public void updateVary(IHasStatus someObject, string vary)
{
someObject.B = vary;
}
If you don't need the concrete classes, you can abstract out the logic like so:
public class Status {
public string A {
get; set;
}
public string B {
get; set;
}
public string C {
get; set;
}
}
public static class StatusManager {
private static Dictionary<string, Status> statusMap = new Dictionary<string,Status>();
public static Status GetStatus(string name) {
Status status;
if (!statusMap.TryGetValue(name, out status))
statusMap[name] = status = new Status();
return status;
}
public static void SetStatus(string name, Status status) {
statusMap[name] = status;
}
public static void UpdateVarx(string name, string varx) {
GetStatus(name).A = varx;
}
// ...
}
If you are a fan of the javascript way of solving multiple switch cases like this
you can always wrap up the switch handlers as Actions and toss them in a Dictionary.
For example : (Source obtained from here)
public class SwitchCase : Dictionary<string,Action>
{
public void Eval(string key)
{
if (this.ContainsKey(key))
this[key]();
else
this["default"]();
}
}
//Now, somewhere else
var mySwitch = new SwitchCase
{
{ "case1", ()=>Console.WriteLine("Case1 is executed") },
{ "case2", ()=>Console.WriteLine("Case2 is executed") },
{ "case3", ()=>Console.WriteLine("Case3 is executed") },
{ "case4", ()=>Console.WriteLine("Case4 is executed") },
{ "default",()=>Console.WriteLine("Default is executed") },
};
mySwitch.Eval(c);
Below code uses all kinds of hacks, not really recommended in production code unless you have a very good reason.
using System;
using System.Linq;
namespace ConsoleApplication1
{
static class Program
{
private static void SetStaticProperty(string className, string propName, string varx)
{
//This sucks, I couldnt find the namespace with easily through reflection :(
string NAMESPACE = "ConsoleApplication1";
Type t = Type.GetType(NAMESPACE + "." + className);
t.GetProperties().Where(p => p.Name == propName).First().SetValue(null, varx, null);
}
public static void updateVarx(string className, string varx)
{
SetStaticProperty(className, "A", varx);
}
public static void updateVary(string className, string vary)
{
SetStaticProperty(className, "B", vary);
}
static void Main(string[] args)
{
updateVarx("Foo", "FooAstring");
updateVarx("Bar", "BarAstring");
updateVarx("Yod", "YodAstring");
updateVary("Foo", "FooBstring");
updateVary("Bar", "BarBstring");
updateVary("Yod", "YodBstring");
Console.WriteLine(Foo.A);
Console.WriteLine(Foo.B);
Console.WriteLine(Bar.A);
Console.WriteLine(Bar.B);
Console.WriteLine(Yod.A);
Console.WriteLine(Yod.B);
Console.ReadLine();
}
}
class Foo
{
public static string A { get; set; }
public static string B { get; set; }
public static string C { get; set; }
}
class Bar
{
public static string A { get; set; }
public static string B { get; set; }
public static string C { get; set; }
}
class Yod
{
public static string A { get; set; }
public static string B { get; set; }
public static string C { get; set; }
}
}
You can use dictionary as configuration and remove the switch statement
Create a dictionary and add append data as below for mapping
//Have dictionary setted up
Dictionary<string, dynamic> m_Dictionary = new Dictionary<string, dynamic>();
m_xmlDictionary.Add("classA",FOO);
m_xmlDictionary.Add("classB",BAR);
m_xmlDictionary.Add("classC",BAR);
//Have dictionary setted up
//change the function as below
public void updatevarx(string class, string varx)
{
m_Dictionary[class].A=varx // Replaced switch statement
}
//while calling use
updatevarx("classC","abc!");// This will assign BAR.A with abc!

Get the index in a multidimensional class

Sorry for the title i will put here an example of what i want to accomplish:
namespace mdclass
{
class pClass
{
static void Main()
{
tiles<int> tl = new tiles<int>();
tl[0].X = 0;
}
}
class tiles<T> : List<T>
{
public int X
{
//get/set the X-coordonate
}
public int Y
{
//get/set the Y-coordonate
}
}
}
how can i transfer the [0] from the tl[0] in the public int X and work with it?
Create a class for x and y coordinates:
public sealed class Point {
public int X { get; set; }
public int Y { get; set; }
}
Use the Point class to store the coordinates into the list:
public sealed class Program {
public static void Main() {
var tiles = new List<Point>();
tiles.Add(new Point { X = 5, Y = 10 });
tiles[0].X = 15;
}
}
Could you not just make tl public?
Then myInt = mypClass.tl[0].X
A data heirachy like this might work for you (no time to add actual code, sorry!). Then you could implement appropriate getters and setters.
Public class Grid {
List<Row>
}
Public class Row{
List<Point>
}
Public Class Point{
public int X { get; set; }
public int Y { get; set; }
}

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