>Digital-flame

C#. Attributes

Posted on 31.08.2017 by Stanislav_Panteleev

Definition

Attributes – descendants of System.Attribute, some kind of annotations of code, applied for some object.

Standart attributes are

[CLSCompliant] – Common Language Specification

[DLLImport]

[Obsolete] – deprecated

[Serializable]

[NonSerialized]

[WebMethod]

Self made attributes also possible

Attribute consumers

Compiler,

some methods of .NET – for example BinaryFormatter,

CLR

SimpleExample

    // one attribute
    [Serializable]
    public class Motorcycle {

        [NonSerialized]
        float weightOfCurrentPassengers;
        bool hasRadioSystem;
        bool hasHeadSet;
        bool hasBar;

        
    }

    // many attributes
    [Serializable,Obsolete("Use another vehicle")]
    public class Horse {
        //...
    }

// one attribute

[Serializable]

public class Motorcycle {

[NonSerialized]

float weightOfCurrentPassengers;

bool hasRadioSystem;

bool hasHeadSet;

bool hasBar;

}

// many attributes

[Serializable,Obsolete("Use another vehicle")]

public class Horse {

//...

}

Writing like this will add errors to Error list because we used Obsolete

   static void Main(string[] args)
        {
            Horse h = new Horse();
        }

static void Main(string[] args)

{

Horse h = new Horse();

}

ShortNames of Attributes

[SerializableAttribute] and [Serializable] the same in C#

Attributes may recieve params in constructor

public sealed class ObsoleteAttribute : Attribute
{
public ObsoleteAttribute();
public ObsoleteAttribute(string message);
public ObsoleteAttribute(string message, bool error);
public bool IsError { get; }
public string Message { get; }
}

public sealed class ObsoleteAttribute : Attribute

{

public ObsoleteAttribute();

public ObsoleteAttribute(string message);

public ObsoleteAttribute(string message, bool error);

public bool IsError { get; }

public string Message { get; }

}

CustomAttributes

AttributedCarLibrary.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

[assembly: CLSCompliant(true) ] // <<< assembly level attributes

namespace AttributedCarLibrary
{
    [AttributeUsage(AttributeTargets.Class| AttributeTargets.Struct,Inherited =false)]
    public sealed class VehicleDescriptionAttribute:System.Attribute
    {
        public string Description { get; set; }
        public VehicleDescriptionAttribute(string ADescription)
        {
            Description = ADescription;
        }
        public VehicleDescriptionAttribute() { }

    }


    // one attribute
    [Serializable, VehicleDescription(Description = "My Rocking Harley")]
    public class Motorcycle
    {

        [NonSerialized]
        float weightOfCurrentPassengers;
        bool hasRadioSystem;
        bool hasHeadSet;
        bool hasBar;


    }

    // many attributes
    [SerializableAttribute]
    [Obsolete("Use another vehicle")]
    [VehicleDescription("The old gray mare")]
    public class Horse
    {
        //...
    }

    [VehicleDescription("A very long, slow auto")]
    public class Winnebago
    {
        //...
    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

[assembly: CLSCompliant(true) ] // <<< assembly level attributes

namespace AttributedCarLibrary

{

[AttributeUsage(AttributeTargets.Class| AttributeTargets.Struct,Inherited =false)]

public sealed class VehicleDescriptionAttribute:System.Attribute

{

public string Description { get; set; }

public VehicleDescriptionAttribute(string ADescription)

{

Description = ADescription;

}

public VehicleDescriptionAttribute() { }

}

// one attribute

[Serializable, VehicleDescription(Description = "My Rocking Harley")]

public class Motorcycle

{

[NonSerialized]

float weightOfCurrentPassengers;

bool hasRadioSystem;

bool hasHeadSet;

bool hasBar;

}

// many attributes

[SerializableAttribute]

[Obsolete("Use another vehicle")]

[VehicleDescription("The old gray mare")]

public class Horse

{

//...

}

[VehicleDescription("A very long, slow auto")]

public class Winnebago

{

//...

}

use of custom attributes

    // many attributes
    [SerializableAttribute]
    [Obsolete("Use another vehicle")]
    [VehicleDescription("The old gray mare")]
    public class Horse
    {
        //...
    }

    [VehicleDescription("A very long, slow auto")]
    public class Winnebago
    {
        //...
    }

// many attributes

[SerializableAttribute]

[Obsolete("Use another vehicle")]

[VehicleDescription("The old gray mare")]

public class Horse

{

//...

}

[VehicleDescription("A very long, slow auto")]

public class Winnebago

{

//...

}

AttributeLimitations

we can use class AttributeTargets like this

    [AttributeUsage(AttributeTargets.Class| AttributeTargets.Struct,Inherited =false)]
    public sealed class VehicleDescriptionAttribute:System.Attribute
    {
        public string Description { get; set; }
        public VehicleDescriptionAttribute(string ADescription)
        {
            Description = ADescription;
        }
        public VehicleDescriptionAttribute() { }

    }

[AttributeUsage(AttributeTargets.Class| AttributeTargets.Struct,Inherited =false)]

public sealed class VehicleDescriptionAttribute:System.Attribute

{

public string Description { get; set; }

public VehicleDescriptionAttribute(string ADescription)

{

Description = ADescription;

}

public VehicleDescriptionAttribute() { }

}

Assembly level attributes

Solution Explorer – > Properties – > AssemblyInfo.cs – fill attributes right in assembly
Also you can write in code before namespace

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

[assembly: CLSCompliant(true) ] // <<< assembly level attributes

namespace AttributedCarLibrary
{
    [AttributeUsage(AttributeTargets.Class| AttributeTargets.Struct,Inherited =false)]
    public sealed class VehicleDescriptionAttribute:System.Attribute
    {
        public string Description { get; set; }
        public VehicleDescriptionAttribute(string ADescription)
        {
            Description = ADescription;
        }
        public VehicleDescriptionAttribute() { }

    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

[assembly: CLSCompliant(true) ] // <<< assembly level attributes

namespace AttributedCarLibrary

{

[AttributeUsage(AttributeTargets.Class| AttributeTargets.Struct,Inherited =false)]

public sealed class VehicleDescriptionAttribute:System.Attribute

{

public string Description { get; set; }

public VehicleDescriptionAttribute(string ADescription)

{

Description = ADescription;

}

public VehicleDescriptionAttribute() { }

}

Reflection Attributes with EarlyBinding

      private static void ReflectOnAttributesUsingEarlyBinding()
        {
            Type t = typeof(Winnebago); // Knowing type Winnebago, so early binding
            object[] customAtts = t.GetCustomAttributes(false);
            foreach (VehicleDescriptionAttribute v in customAtts)
            Console.WriteLine("->{0}\n",v.Description);
        }

private static void ReflectOnAttributesUsingEarlyBinding()

{

Type t = typeof(Winnebago); // Knowing type Winnebago, so early binding

object[] customAtts = t.GetCustomAttributes(false);

foreach (VehicleDescriptionAttribute v in customAtts)

Console.WriteLine("->{0}\n",v.Description);

}

full example

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using AttributedCarLibrary;

namespace ApplyingAttributes
{
    class Program
    {
        static void Main(string[] args)
        {
            // Horse h = new Horse(); // << Obsolete example
            ReflectOnAttributesUsingEarlyBinding();
            Console.ReadLine();


        }

        private static void ReflectOnAttributesUsingEarlyBinding()
        {
            Type t = typeof(Winnebago);
            object[] customAtts = t.GetCustomAttributes(false);
            foreach (VehicleDescriptionAttribute v in customAtts)
            Console.WriteLine("->{0}\n",v.Description);
        }

    }



}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using AttributedCarLibrary;

namespace ApplyingAttributes

{

class Program

{

static void Main(string[] args)

{

// Horse h = new Horse(); // << Obsolete example

ReflectOnAttributesUsingEarlyBinding();

Console.ReadLine();

}

private static void ReflectOnAttributesUsingEarlyBinding()

{

Type t = typeof(Winnebago);

object[] customAtts = t.GetCustomAttributes(false);

foreach (VehicleDescriptionAttribute v in customAtts)

Console.WriteLine("->{0}\n",v.Description);

}

Reflection Attributes with lateBinding

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;

namespace AttrReaderLateBinding
{
    class Program
    {
        static void Main(string[] args)
        {
            ReflectAttsLateBinding();
            Console.ReadLine();
        }

        private static void ReflectAttsLateBinding()
        {
            try
            {
                Assembly asm = Assembly.LoadFrom("AttributedCarLibrary.dll");
                Type vehicleDesc = asm.GetType("AttributedCarLibrary.VehicleDescriptionAttribute");
                PropertyInfo pDesc = vehicleDesc.GetProperty("Description");
                Type[] types = asm.GetTypes();
                foreach (Type t in types)
                {
                    object[] objs = t.GetCustomAttributes(vehicleDesc, false);
                    foreach (object o in objs)
                    {
                        Console.WriteLine("->{0}:{1}\n", t.Name, pDesc.GetValue(o, null));
                    }
                }
            }

            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }

        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Reflection;

namespace AttrReaderLateBinding

{

class Program

{

static void Main(string[] args)

{

ReflectAttsLateBinding();

Console.ReadLine();

}

private static void ReflectAttsLateBinding()

{

try

{

Assembly asm = Assembly.LoadFrom("AttributedCarLibrary.dll");

Type vehicleDesc = asm.GetType("AttributedCarLibrary.VehicleDescriptionAttribute");

PropertyInfo pDesc = vehicleDesc.GetProperty("Description");

Type[] types = asm.GetTypes();

foreach (Type t in types)

{

object[] objs = t.GetCustomAttributes(vehicleDesc, false);

foreach (object o in objs)

{

Console.WriteLine("->{0}:{1}\n", t.Name, pDesc.GetValue(o, null));

}

catch (Exception ex)

{

Console.WriteLine(ex.Message);

}

Posted in C# | Comments Off

С#. LateBindingExamples

Posted on 30.08.2017 by Stanislav_Panteleev

Late binding means – we can create instance not in compilation time but in execution and call methods with or without params

-invoke methods with / without params

-setting private fields

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;
using System.IO;

namespace LateBindingApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("***Fun with Late Binding***");
            Assembly a = null;
            try { a = Assembly.LoadFrom("C:\\C#\\MyC#StudyProjects\\07_DifferentMains\\LateBindingApp\\LateBindingApp\\bin\\Debug\\CarLibrary2.dll"); }
            catch (FileNotFoundException ex) { Console.WriteLine(ex.Message); return; }

            if (a != null) CreateUsingLateBinding(a);
            Console.ReadLine();

        }

        static void CreateUsingLateBinding(Assembly asm)
        {
            try
            {
                Type miniVan = asm.GetType("CarLibrary.MiniVan");
                object obj = Activator.CreateInstance(miniVan);

                // call method with reflection
                MethodInfo mi = miniVan.GetMethod("TurboBoost"); // invoke method without params
                mi.Invoke(obj, null);

                // call method with reflection with params
                MethodInfo mi1 = miniVan.GetMethod("TurnOnRadio"); // invoke method with params
                //object[] paramsArray=new object[] {true, "someRadioMessage"}
                mi1.Invoke(obj, new object[] { true, "someRadioMessage" });

                // setting private field
                // typeof(Foo).GetField("_bar", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(objectForFoocClass, "newValue");
                miniVan.GetField("SomeField", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(obj, "SomeValue");

                // getting private field
                // var _barVariable = typeof(Foo).GetField("_bar", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(objectForFooClass);
                var fieldValue =miniVan.GetField("SomeField", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(obj);
                Console.WriteLine(fieldValue);


                Console.WriteLine("Created a {0} using late binding!", obj);
            }
            catch (Exception e) { Console.WriteLine(e.Message); }
        }
    }



}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Reflection;

using System.IO;

namespace LateBindingApp

{

class Program

{

static void Main(string[] args)

{

Console.WriteLine("***Fun with Late Binding***");

Assembly a = null;

try { a = Assembly.LoadFrom("C:\\C#\\MyC#StudyProjects\\07_DifferentMains\\LateBindingApp\\LateBindingApp\\bin\\Debug\\CarLibrary2.dll"); }

catch (FileNotFoundException ex) { Console.WriteLine(ex.Message); return; }

if (a != null) CreateUsingLateBinding(a);

Console.ReadLine();

}

static void CreateUsingLateBinding(Assembly asm)

{

try

{

Type miniVan = asm.GetType("CarLibrary.MiniVan");

object obj = Activator.CreateInstance(miniVan);

// call method with reflection

MethodInfo mi = miniVan.GetMethod("TurboBoost"); // invoke method without params

mi.Invoke(obj, null);

// call method with reflection with params

MethodInfo mi1 = miniVan.GetMethod("TurnOnRadio"); // invoke method with params

//object[] paramsArray=new object[] {true, "someRadioMessage"}

mi1.Invoke(obj, new object[] { true, "someRadioMessage" });

// setting private field

// typeof(Foo).GetField("_bar", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(objectForFoocClass, "newValue");

miniVan.GetField("SomeField", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(obj, "SomeValue");

// getting private field

// var _barVariable = typeof(Foo).GetField("_bar", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(objectForFooClass);

var fieldValue =miniVan.GetField("SomeField", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(obj);

Console.WriteLine(fieldValue);

Console.WriteLine("Created a {0} using late binding!", obj);

}

catch (Exception e) { Console.WriteLine(e.Message); }

}

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C#. Dynamically loaded assembly

Posted on 30.08.2017 by Stanislav_Panteleev

Load and LoadFrom commands…

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;
using System.IO;

namespace ExternalAssemblyReflector2
{
    class Program
    {

        static void DisplayTypesInAsm(Assembly asm) {
            Console.WriteLine("***Types in assembly***");
            Console.WriteLine("->{0}",asm.FullName);
            Type[] types = asm.GetTypes();
            foreach (Type t in types) Console.WriteLine("Type :{0}",t);
            Console.WriteLine("");
        }

        static void Main(string[] args)
        {

            Console.WriteLine("***External Assembly Viewer");
            string asmName = "";
            Assembly asm = null;
            do {
                Console.WriteLine("\nEnter assembly to evaluate");
                Console.WriteLine("or enter Q to quit");
                asmName = Console.ReadLine();
                if (asmName.ToUpper() == "Q") { break; }
                try { asm = Assembly.LoadFrom(asmName); // Load also possible but LoadFrom has more wide context
                    DisplayTypesInAsm(asm);
                } catch { Console.WriteLine("Sorry can't find assembly");  }

            }

            while(true);

        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Reflection;

using System.IO;

namespace ExternalAssemblyReflector2

{

class Program

{

static void DisplayTypesInAsm(Assembly asm) {

Console.WriteLine("***Types in assembly***");

Console.WriteLine("->{0}",asm.FullName);

Type[] types = asm.GetTypes();

foreach (Type t in types) Console.WriteLine("Type :{0}",t);

Console.WriteLine("");

}

static void Main(string[] args)

{

Console.WriteLine("***External Assembly Viewer");

string asmName = "";

Assembly asm = null;

do {

Console.WriteLine("\nEnter assembly to evaluate");

Console.WriteLine("or enter Q to quit");

asmName = Console.ReadLine();

if (asmName.ToUpper() == "Q") { break; }

try { asm = Assembly.LoadFrom(asmName); // Load also possible but LoadFrom has more wide context

DisplayTypesInAsm(asm);

} catch { Console.WriteLine("Sorry can't find assembly"); }

}

while(true);

}

This will give

***External Assembly Viewer

Enter assembly to evaluate
or enter Q to quit
CarLibrary.dll
***Types in assembly***
->CarLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=6a9228aea5de13fa
Type :CarLibrary.EngineState
Type :CarLibrary.Car
Type :CarLibrary.SportsCar
Type :CarLibrary.MiniVan

***External Assembly Viewer

Enter assembly to evaluate

or enter Q to quit

CarLibrary.dll

***Types in assembly***

->CarLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=6a9228aea5de13fa

Type :CarLibrary.EngineState

Type :CarLibrary.Car

Type :CarLibrary.SportsCar

Type :CarLibrary.MiniVan

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C#. Reflection

Posted on 30.08.2017 by Stanislav_Panteleev

Reflection – getting info about type during execution.

using System.Reflection;

1	using System.Reflection;

#1 Need instance and info about type, before getting type

   SportsCar viper = new SportsCar("Viper",240,40);
            Type t = viper.GetType();
            Console.WriteLine("Type of viper is: "+t);
            Console.ReadLine();

SportsCar viper = new SportsCar("Viper",240,40);

Type t = viper.GetType();

Console.WriteLine("Type of viper is: "+t);

Console.ReadLine();

#2 Need info about type before getting type

SportsCar viper = new SportsCar("Viper",240,40);
            Type t = typeof(SportsCar);

1 2	SportsCar viper = new SportsCar("Viper",240,40); Type t = typeof(SportsCar);

#3 in current assembly with string param

//in current assembly
 Type t = Type.GetType("CarLibrary.SportsCar",false,true);

1 2	//in current assembly Type t = Type.GetType("CarLibrary.SportsCar",false,true);

#4 in external assembly GAC

//in external assembly GAC
Type t = Type.GetType("CarLibrary.SportsCar,CarLibrary");

1 2	//in external assembly GAC Type t = Type.GetType("CarLibrary.SportsCar,CarLibrary");

#5 for generic types

Type t = Type.GetType("System.Collections.Generic.List`1", false, true);
            Console.WriteLine(t);
            Console.ReadLine();

Type t = Type.GetType("System.Collections.Generic.List`1", false, true);

Console.WriteLine(t);

Console.ReadLine();

Type t = Type.GetType("System.Collections.Generic.Dictionary`2", false, true);
            Console.WriteLine(t);
            Console.ReadLine();

Type t = Type.GetType("System.Collections.Generic.Dictionary`2", false, true);

Console.WriteLine(t);

Console.ReadLine();

Reflection of methods, fields, properties,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;

namespace ReflectionExample
{
    class Program
    {
        static void Main(string[] args)
        {
    

            Console.WriteLine("***Welcome to MyTypeViewer");
            string typeName = "";
            do {
                Console.WriteLine("\nEnter a type name to evaluate");
                Console.WriteLine("Or Enter Q to quit");
                typeName = Console.ReadLine();
                if (typeName == "Q") { break; }
                try {
                    Type t = Type.GetType(typeName);
                    Console.WriteLine("");
                    ListVariousStats(t);
                    ListFieldsLinq(t);
                    ListPropertiesLinq(t);
                    ListMethodsLinqOnlyNames(t);
                    ListInterfacesLinq(t);
                } catch { Console.WriteLine("Sorry, can't find type"); }


            } while (true);

        }

        //--- reflection of methods with paramInfo
        static void ListMethods(Type t) {
            Console.WriteLine("***ListMethods***");
            MethodInfo[] mi = t.GetMethods();
            foreach (MethodInfo m in mi) //Console.WriteLine("->{0}", m.Name);
            {
                string retVal = m.ReturnType.FullName;
                string paramInfo = "(";
                foreach (ParameterInfo pi in m.GetParameters())
                { paramInfo += string.Format("{0} {1}",pi.ParameterType,pi.Name); }
                paramInfo += ")";
                Console.WriteLine("{0} {1} {2}", retVal,m.Name, paramInfo);

            }
            Console.WriteLine();
        }

        static void ListMethodsLinq(Type t)
        {
            Console.WriteLine("***ListMethods***");
            MethodInfo[] mi = t.GetMethods(); // << for what?
            var subset = from n in t.GetMethods() select n;
            foreach (var name in subset) Console.WriteLine("->{0}", name);
            Console.WriteLine();

        }


        static void ListMethodsLinqOnlyNames(Type t)
        {
            Console.WriteLine("***ListMethods***");
            var subset = from n in t.GetMethods() select n.Name;
            foreach (var name in subset) Console.WriteLine("->{0}",name);
          

            Console.WriteLine();            
            
        }


        //--- reflection of fields
        static void ListFieldsLinq(Type t)
        {
            Console.WriteLine("***ListFields***");
            var subset = from f in t.GetFields() select f.Name;
            foreach (var name in subset) Console.WriteLine("->{0}", name);
            Console.WriteLine();
        }

        //--- reflection of properties
        static void ListPropertiesLinq(Type t)
        {
            Console.WriteLine("***ListProperties***");
            var subset = from p in t.GetProperties() select p.Name;
            foreach (var name in subset) Console.WriteLine("->{0}", name);
            Console.WriteLine();
        }

        //--- reflection of interfaces
        static void ListInterfacesLinq(Type t)
        {
            Console.WriteLine("***ListInterfaces***");
            var subset = from i in t.GetInterfaces() select i;
            // foreach (var name in subset) Console.WriteLine("->{0}", name);
            foreach (var i in subset) Console.WriteLine("->", (i as Type).Name);
            Console.WriteLine();
        }

        static void ListVariousStats(Type t) {
            Console.WriteLine("***Various stats***");
            Console.WriteLine("Base class is: {0}",t.BaseType);
            Console.WriteLine("Is type abstract?: {0}", t.IsAbstract);
            Console.WriteLine("Is sealed: {0}", t.IsSealed);
            Console.WriteLine("Is generic: {0}", t.IsGenericTypeDefinition);
            Console.WriteLine("Is type a class type: {0}", t.IsClass);
            Console.WriteLine();

        }

    }
}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Reflection;

namespace ReflectionExample

{

class Program

{

static void Main(string[] args)

{

Console.WriteLine("***Welcome to MyTypeViewer");

string typeName = "";

do {

Console.WriteLine("\nEnter a type name to evaluate");

Console.WriteLine("Or Enter Q to quit");

typeName = Console.ReadLine();

if (typeName == "Q") { break; }

try {

Type t = Type.GetType(typeName);

Console.WriteLine("");

ListVariousStats(t);

ListFieldsLinq(t);

ListPropertiesLinq(t);

ListMethodsLinqOnlyNames(t);

ListInterfacesLinq(t);

} catch { Console.WriteLine("Sorry, can't find type"); }

} while (true);

}

//--- reflection of methods with paramInfo

static void ListMethods(Type t) {

Console.WriteLine("***ListMethods***");

MethodInfo[] mi = t.GetMethods();

foreach (MethodInfo m in mi) //Console.WriteLine("->{0}", m.Name);

{

string retVal = m.ReturnType.FullName;

string paramInfo = "(";

foreach (ParameterInfo pi in m.GetParameters())

{ paramInfo += string.Format("{0} {1}",pi.ParameterType,pi.Name); }

paramInfo += ")";

Console.WriteLine("{0} {1} {2}", retVal,m.Name, paramInfo);

}

Console.WriteLine();

}

static void ListMethodsLinq(Type t)

{

Console.WriteLine("***ListMethods***");

MethodInfo[] mi = t.GetMethods(); // << for what?

var subset = from n in t.GetMethods() select n;

foreach (var name in subset) Console.WriteLine("->{0}", name);

Console.WriteLine();

}

static void ListMethodsLinqOnlyNames(Type t)

{

Console.WriteLine("***ListMethods***");

var subset = from n in t.GetMethods() select n.Name;

foreach (var name in subset) Console.WriteLine("->{0}",name);

Console.WriteLine();

}

//--- reflection of fields

static void ListFieldsLinq(Type t)

{

Console.WriteLine("***ListFields***");

var subset = from f in t.GetFields() select f.Name;

foreach (var name in subset) Console.WriteLine("->{0}", name);

Console.WriteLine();

}

//--- reflection of properties

static void ListPropertiesLinq(Type t)

{

Console.WriteLine("***ListProperties***");

var subset = from p in t.GetProperties() select p.Name;

foreach (var name in subset) Console.WriteLine("->{0}", name);

Console.WriteLine();

}

//--- reflection of interfaces

static void ListInterfacesLinq(Type t)

{

Console.WriteLine("***ListInterfaces***");

var subset = from i in t.GetInterfaces() select i;

// foreach (var name in subset) Console.WriteLine("->{0}", name);

foreach (var i in subset) Console.WriteLine("->", (i as Type).Name);

Console.WriteLine();

}

static void ListVariousStats(Type t) {

Console.WriteLine("***Various stats***");

Console.WriteLine("Base class is: {0}",t.BaseType);

Console.WriteLine("Is type abstract?: {0}", t.IsAbstract);

Console.WriteLine("Is sealed: {0}", t.IsSealed);

Console.WriteLine("Is generic: {0}", t.IsGenericTypeDefinition);

Console.WriteLine("Is type a class type: {0}", t.IsClass);

Console.WriteLine();

}

Posted in C# | Comments Off

C#. Shared assembly

Posted on 30.08.2017 by Stanislav_Panteleev

Lets use Carlib.dll from One file Assembly

1. Strong name

Properties – > Signing – > Sign the assembly -> New – > SomeName (for ex. myKeyPair.snk)

2. Install assembly to GAC (Global Assembly Cache)

go to

C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Visual Studio 2015\Visual Studio Tools\Developer Command Prompt for VS2015

start Developer Command Prompt for VS2015 with Admin rights

write something like

C:\C#\MyC#StudyProjects\07_DifferentMains\CarLibrary\CarLibrary\bin\Debug>gacutil -i CarLibrary.dll

and receive

Сборка успешно добавлена в кэш

check if assembly in GAC

C:\C#\MyC#StudyProjects\07_DifferentMains\CarLibrary\CarLibrary\bin\Debug>gacutil -l CarLibrary

and receive

В глобальном кэше сборок содержатся следующие сборки:
CarLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=6a9228aea5de13fa, processorArchitecture=MSIL

Число элементов = 1

3. Use assembly

In MS Visual Studio – Class View – right click add Reference – > Browse

add assembly to solution… go to…

C:\Windows\Microsoft.NET\assembly\GAC_MSIL\CarLibrary\v4.0_1.0.0.0__6a9228aea5de13fa

and add CarLib.dll

4. Use it in project – now assembly not copied to location of program

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using CarLibrary; // <<

namespace SharedCarClient
{
    class Program
    {
        static void Main(string[] args)
        {
            SportsCar c = new SportsCar();
            c.TurboBoost();
            Console.ReadLine();
        }
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using CarLibrary; // <<

namespace SharedCarClient

{

class Program

{

static void Main(string[] args)

{

SportsCar c = new SportsCar();

c.TurboBoost();

Console.ReadLine();

}

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С#. Assembly theory

Posted on 29.08.2017 by Stanislav_Panteleev

Assembly – versioned (for ex. 1.0.0.0), self described( has manifest, links to other external assemblies, info about all types) binary, supported by CLR (Common Language Runtime). One EXE is divided in may exe, dll files.

Assembly defines type borders. Example. Both MyCars.dll and YourCars.dll has CarLibrary that has SportsCar class. It will be 2 different classes.

Private assembly – in the same catalogue with client app.

Shared Assembly – in Global Assembly Cache

Assembly consists of:

Windows headers file
CLR headers file
CIL code
Types metadata
Manifest
Additional resources

Windows headers file

(

how to open it?

C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Visual Studio 2015\Visual Studio Tools\Developer Command Prompt for VS2015

for example

Dump of file C:\C#\MyC#StudyProjects\07_DifferentMains\nameSpaceExamples\nameSpaceExamples\bin\Debug\nameSpaceExamples.exe

)

CLR Headers file

dumpbin /clrheader C:\C#\MyC#StudyProjects\07_DifferentMains\nameSpaceExamples\nameSpaceExamples\bin\Debug\nameSpaceExamples.exe

CIL code compiled on current platform with JIT (Just in time compiler)

Type metadata – where in binary types ?

Manifest – list of modules, version, all external assemblies

Additional resources for pics and other files. Also satellite assemblies possible.

One file and many files assemblies

module – binary file of .NET

One file assembly Carlibrary.dll

Many files assembly – many files with *.netmodule extension and one main file (*.exe or *.dll) and one version number. Main file and *.netmodules have manifests. it is one logically, but on physics level – many files

Advantage – can be loaded when needed (dynamically), allows use different programming languages (like dll in Delphi).

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C#. Creating one file assembly. Example

Posted on 29.08.2017 by Stanislav_Panteleev

Lets create CarLibrary.dll assembly

File NewProject ClassLibrary

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CarLibrary
{
    public enum EngineState {EngineAlive, engineDead}

    public abstract class Car
    {
        public string PetName { get; set; }
        public int CurrentSpeed { get; set; }
        public int MaxSpeed { get; set; }
        protected EngineState egnState = EngineState.EngineAlive;
        public EngineState EngineState {get { return egnState; }}
        public abstract void TurboBoost();
        public Car(){}
        public Car(string name, int maxSp, int currSp) {
            PetName = name; MaxSpeed = maxSp; CurrentSpeed = currSp;
        }
    }


}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace CarLibrary

{

public enum EngineState {EngineAlive, engineDead}

public abstract class Car

{

public string PetName { get; set; }

public int CurrentSpeed { get; set; }

public int MaxSpeed { get; set; }

protected EngineState egnState = EngineState.EngineAlive;

public EngineState EngineState {get { return egnState; }}

public abstract void TurboBoost();

public Car(){}

public Car(string name, int maxSp, int currSp) {

PetName = name; MaxSpeed = maxSp; CurrentSpeed = currSp;

}

In other file Derived.cs 2 derived classes

ClassView – addReference – System.Windows.Forms

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using CarLibrary;
using System.Windows.Forms;

namespace CarLibrary
{
    public class SportsCar : Car
    {
                                  
        public SportsCar() { }
        public SportsCar(string name, int maxSp, int currSp) : base(name, maxSp, currSp) { }
        public override void TurboBoost() { MessageBox.Show("Turbo Boost Sports Car"); }
   
}

    public class MiniVan : Car
    {

        public MiniVan() { }
        public MiniVan(string name, int maxSp, int currSp) : base(name, maxSp, currSp) { }
        public override void TurboBoost() { MessageBox.Show("Turbo Boost MiniVan"); }

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using CarLibrary;

using System.Windows.Forms;

namespace CarLibrary

{

public class SportsCar : Car

{

public SportsCar() { }

public SportsCar(string name, int maxSp, int currSp) : base(name, maxSp, currSp) { }

public override void TurboBoost() { MessageBox.Show("Turbo Boost Sports Car"); }

}

public class MiniVan : Car

{

public MiniVan() { }

public MiniVan(string name, int maxSp, int currSp) : base(name, maxSp, currSp) { }

public override void TurboBoost() { MessageBox.Show("Turbo Boost MiniVan"); }

}

Now lets create new project CarClient

ClassView – addReference – Browse – CarLibrary.dll

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using CarLibrary;

namespace CarClient
{
    class Program
    {
        static void Main(string[] args)
        {
            SportsCar viper = new SportsCar("Viper",240,40);
            viper.TurboBoost();

            MiniVan mv = new MiniVan();
            mv.TurboBoost();
            Console.ReadLine();

        }

    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using CarLibrary;

namespace CarClient

{

class Program

{

static void Main(string[] args)

{

SportsCar viper = new SportsCar("Viper",240,40);

viper.TurboBoost();

MiniVan mv = new MiniVan();

mv.TurboBoost();

Console.ReadLine();

}

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C#. Namespace examples

Posted on 28.08.2017 by Stanislav_Panteleev

123

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MyShapes;
using The3DHexagon=My3DShapes.Hexagon; // alias for class with same name

namespace CustomNameSpace
{
    class Program
    {
        static void Main(string[] args)
        {
            // one way
            Hexagon h = new Hexagon();
            Circle c = new Circle();
            Square s = new Square();

            //another, no need to write using MyShapes
            MyShapes.Hexagon h1 = new Hexagon();
            MyShapes.Circle c1 = new Circle();
            MyShapes.Square s1 = new Square();

            //
            The3DHexagon h2 = new The3DHexagon();
        }
    }

    namespace someEmbedded {

        public class SomeClass {
            Hexagon h = new Hexagon();
        }
    }    

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using MyShapes;

using The3DHexagon=My3DShapes.Hexagon; // alias for class with same name

namespace CustomNameSpace

{

class Program

{

static void Main(string[] args)

{

// one way

Hexagon h = new Hexagon();

Circle c = new Circle();

Square s = new Square();

//another, no need to write using MyShapes

MyShapes.Hexagon h1 = new Hexagon();

MyShapes.Circle c1 = new Circle();

MyShapes.Square s1 = new Square();

The3DHexagon h2 = new The3DHexagon();

}

namespace someEmbedded {

public class SomeClass {

Hexagon h = new Hexagon();

}

Circle.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MyShapes
{
    class Circle
    {
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace MyShapes

{

class Circle

{

}

Hexagon.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MyShapes
{
    class Hexagon
    {
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace MyShapes

{

class Hexagon

{

}

Square.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MyShapes
{
    class Square
    {
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace MyShapes

{

class Square

{

}

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C#. Delegates, Func, Action

Posted on 27.08.2017 by Stanislav_Panteleev

Ну, есть ключевое слово delegate — это описание сигнатуры функции, т. е., её списка параметров и типа возвращаемого значения. Используется так:

public delegate bool MyPredicate(int x);

1	public delegate bool MyPredicate(int x);

Им можно пользоваться так:

private bool IsOdd(int i) { return i % 2 != 0; }

private Analyze(MyPredicate p, int x)
{
    bool result = p(x);
    if (result)
        Console.WriteLine("found!");
}

Analyze(IsOdd, 1); // печатает "found!"

private bool IsOdd(int i) { return i % 2 != 0; }

private Analyze(MyPredicate p, int x)

{

bool result = p(x);

if (result)

Console.WriteLine("found!");

}

Analyze(IsOdd, 1); // печатает "found!"

С другой стороны, есть готовые, предопределённые сигнатуры функций (Func<TArg1, TArg2, ..., TResult> с возвращаемым значением, Action<TArg1, Targ2, ...> без). То есть, можно не определять делегат самому, а воспользоваться готовыми Func и Action. Аналогичный пример:

private bool IsOdd(int i) { return i % 2 != 0; }

private Analyze(Func<int, bool> p, int x)
{
    bool result = p(x);
    if (result)
        Console.WriteLine("found!");
}

Analyze(IsOdd, 1); // печатает "found!"

private bool IsOdd(int i) { return i % 2 != 0; }

private Analyze(Func<int, bool> p, int x)

{

bool result = p(x);

if (result)

Console.WriteLine("found!");

}

Analyze(IsOdd, 1); // печатает "found!"

Если для вашей сигнатуры подходит Func или Action, особого смысла определять свой делегат нету. Или есть, если вы хотите дать своему делегату более подходящее имя, чем просто Func, и хотите подчеркнуть его семантику.

Существуют случаи, когда свой делегат всё же необходимо объявлять. Например, наличие out– и ref-параметров:

public delegate Updater(ref int x); // невозможно выразить через Func

1	public delegate Updater(ref int x); // невозможно выразить через Func

Для полноты, вот (надеюсь, полный) список вариантов, когда вам придётся объявлять делегат:

Когда список аргументов чересчур длинный (для .NET 4+ более 16 аргументов, для .NET 3.5 больше 4 аргументов)
Когда ваши аргументы содержат ref, out или params.
Если ваш делегат рекурсивен (например delegate D D(D d)). Как ни странно, такие штуки иногда нужны.

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C#. Func template for delegates

Posted on 27.08.2017 by Stanislav_Panteleev

123

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace FuncExample
{
    // what is Func - is prepared delegate - no need to define own delegate

    class Program
    {
        static void Main(string[] args)
        {
            Calc c = new Calc();
            Console.WriteLine(c.Execute(Add,1,2));
            Console.ReadLine();
        }


        public static double Add(int a1, int a2) { return a1 + a2; }
    }

    class Calc {
        
        public double Execute(Func<int,int, double> function, int arg1, int arg2) {
               return function(arg1,arg2);            
        }

        
    }
}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace FuncExample

{

// what is Func - is prepared delegate - no need to define own delegate

class Program

{

static void Main(string[] args)

{

Calc c = new Calc();

Console.WriteLine(c.Execute(Add,1,2));

Console.ReadLine();

}

public static double Add(int a1, int a2) { return a1 + a2; }

}

class Calc {

public double Execute(Func<int,int, double> function, int arg1, int arg2) {

return function(arg1,arg2);

}

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C#. Attributes

Definition

Attribute consumers

SimpleExample

ShortNames of Attributes

CustomAttributes

AttributeLimitations

Assembly level attributes

Reflection Attributes with EarlyBinding

Reflection Attributes with lateBinding

С#. LateBindingExamples

C#. Dynamically loaded assembly

C#. Reflection

C#. Shared assembly

С#. Assembly theory

Windows headers file

One file and many files assemblies

C#. Creating one file assembly. Example

C#. Namespace examples

C#. Delegates, Func, Action

C#. Func template for delegates

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