A Simple Tutorial on using a Class Library and C# application in one Solution.

A Simple tutorial on creating a class library and implementing a class in a C# application in one solution thereof. Just something to get you started no unnecessary detail.

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Closed Caption:

i'm just going to show you guys how to
create a cross librarian and basic
example on your current track and we'll
just use a class library as sort of a
container told all our classes and
created the aisle from that and with the
ll be able to access all the classes and
and the pretty advantage of of DLLs is
that it
it's a form of polymorphism if you
haven't heard about that triggers should
look it up but basically introduced fire
visual studio it didn't work when I was
trying to show you guys during the SI
and murphy's law wasn't with me clearly
but I'm gonna start by creating a new
project from the what I'm going to do
first to create my class library like
that and our name my class lightly
university library i can remember you
think of a universe class library is
sort of like just a container and and
and and nothing else so I'm just gonna
trade this thing in this folder school
2014 create a new folder bit of lag on
my pc because of the screen capture
software and i'm just going to call this
say practical
deal out from there select at fordham
let's just go back quickly and say
select folder select photo
ok so it will be created in that photo
and recorded university library and
selected a class library click ok and
after that it's gonna fire it up
come on
so it creates a default class wanting
you have one class created for you and
it's called class 1 what I'm going to do
is I'm just going to rename this class
and make it to parent dress which is
student remember you can have two other
classes that inherit from the student
class tickets for that ok and creates my
student class from the minute rate maybe
my two other classes i'll click Add
class so you can take new item and go to
class classes the shortcut to wait for
it to load
take its time and I'm not a very patient
person but probably because of the
screen capture software it's making my
pc leg anyway once you've created the
relative got into this window I just
want to create a boxer
click Add and the next one will be
another class create another trust and I
want to call this class offer and
something that we did last term is that
we did a bit of inheritance you didn't
write that in your test but you just use
a semicolon and then you write the the
class where you would like to hear it
often hear from student meaning that all
the information that's fine and student
golfer will be able to access the
student will store just general
information about his finger is a golf
balls store more specific information
same thing with box i go to my boxer I
put a semicolon and in the right to
student gavel pretty simple
I'm not going to put any information and
here you guys can throw around that you
know about that coding same thing with
gender I'm not going to put any
information i'm just going to show you
how to create the dr from there what you
can do is you can click sorry you can
click bold sorry
so it for to rebuild
camera once it's done building is right
click over here and you click boat again
and that will create the jello I can
show you the diol that it's created by
right-clicking in and open for din file
explorer what might been my debug and is
the deal that was created this deal out
is the one that holds all the classes
that I'm going to need which is close
that down over there sorry mom and I
want to add a new project now pay
attention to where i'm clicking when i
was adding my classes i right click over
here on the actual trust library project
but now i'm taking the whole solution
and I'm right-clicking I'm saying add
and I'm saying I'm new project now this
time I'm not creating a class library
but i'm creating it could be a windows
forms application a WPF windows
presentation foundation application or
concept occasion we're just going to
create the windows forms application i'm
gonna call it sports bureau sports kill
myself with the spinning row whatever
however you spell genuine once you've
done that i'm not going to fill around
the location or anything i'm just going
to leave it the way it is but you could
have created this somewhere else i'm not
going to fool around with that and i'm
gonna kick him once that is complete
it's going to create for you a a project
name Sports Bureau now you need to bear
in mind that now you have two projects
in this one solution to projects in one
solution your solution is called
university library you can change the
name of the solution over here if you if
you really want to and that's just the
property in the properties window i'm
not going to fool around with that you
guys don't need 24 around with that for
now now a one thing that might be
important and when you try to run this
it it might give you an error is
probably going to give me and gives it a
project with an opera type of class like
we cannot be stored directly which means
that you can't run
you can't run a a class library sorry
about that was my phone so what you need
to do is you need to click the project
that has the form which is this one so
if I click this project in our right
click it and I say sit as starter
project when i run at this time it will
run the windows forms up forms
application that's a common error that
some people sometimes get now the the
big thing that you want to do now is you
you probably want to add the reference i
remember in first year to add a
reference for windows forms same
procedure over him you're right click
and you go ad reference to go to browse
and I'm just going to go right out of
here so that we get to the right project
now remember I called the whole the for
practical d alone and double-click that
I go to the University Library go to
university library I could have been
with bug and I click the dexterity laksa
can add that are added to this holiest
of Els that you may have been using once
you've done that make sure that the
correct one is selected you click OK
again the university library dll would
have been added now let's say we wanted
to use this in our forum so I'm just
gonna be just using a very simple
example I hour and you need the
namespace which is using University
Library little shop immediately if it
doesn't show up you probably created
your files in the incorrect order of
something like that and just start again
from there now I have access to all
those classes within the university
libraries so if i want to create a
student objects are student in me is
encroaching new student and that will
create a a student object now I'm
surprised it's not giving me an error
maybe you find its supposed to give me
an error of the student doesn't have a
constructor that takes zero but it's not
giving me an error
meaning I'm not as smart as I perceive
myself turbulence is bold and see if
it's going to give me an error after
build now it is both succeed so that's
simply how you create a class library
with all audio your classes within it
and and then you implement that in your
your forms application you could do this
with the asp.net application it's all
the same
now the beauty of this is you could use
the same class library for multiple
platforms you can use it for you for
your Windows Phone app or you could use
it for your asp.net app annual interest
for map and or in combination will use
one class that means you don't have to
create new classes
let's say I want to create a boxer
I just say boxer boxer again the box is
not showing up so let's go have a full
around and see what could that the
problem could let the problem maybe it's
try putting public in um so programming
is about getting into trouble and try to
get yourself up without panicking so
let's try that again we have to bow that
one small because i made a change to my
classroom is on board camera and once
it's built it should update Watson you
but just as a precaution that's maybe
both the whole of the whole folder whole
solution can I do that
no let's just put this one as well
and after that we can try and box area
and boxing shows up so there's a sort of
the protection level that is giving me a
problem