public AddLecturesViewModel()
{
foreach (var uniqueGroup in _lecturesStorageModel.UniqueGroups)
{
Audiences.Add(uniqueGroup);
}
foreach (var uniqueTeacher in _lecturesStorageModel.UniqueTeachers)
{
Lecturers.Add(uniqueTeacher);
}
foreach (var combinedLecture in _lecturesStorageModel.CombinedLectures)
{
Lectures.Add(combinedLecture);
}
_lectures = new List <Lecture>(_lecturesStorageModel.Lectures);
if (_lecturesStorageModel.CombinedLectures != null && _lecturesStorageModel.CombinedLectures.Count > 0)
{
FillCombinedLectures();
}
UpdateLists();
UpdateLectures();
}
private CollectionDataService()
{
var xmlRegionCollection = context
.Deserialize <RegionsCollection>("..\\..\\Data_Source\\RegionsData.xml")
.Region;
RegionCollection.AddRange(xmlRegionCollection);
var xmlGendersType = context
.Deserialize <GendersCollection>("..\\..\\Data_Source\\GenderData.xml")
.Gender;
GenderTypes.AddRange(xmlGendersType);
var xmlSubjects = context
.Deserialize <SubjectsCollection>("..\\..\\Data_Source\\SubjectsWithStudentsData.xml")
.Subjects;
SubjWithStudents.AddRange(xmlSubjects);
var users = context
.Deserialize <UsersCollection>("..\\..\\Data_Source\\UniversitySystemData.xml");
List <Lecturer> xmlLecturers = users.Lecturers;
Lecturers.AddRange(xmlLecturers);
List <Student> xmlStudents = users.Students;
Students.AddRange(xmlStudents);
}
public bool AddProject(ProjectModel model, ref string errorMessage)
{
using (SZPNUWContext context = new SZPNUWContext())
{
Lecturers lecturer = context.Lecturers.FirstOrDefault(x => x.Userid == model.UserId);
if (lecturer == null)
{
errorMessage = PortalMessages.UserDoesNotExist;
return(false);
}
if (!context.Projects.Any(x => x.Topic == model.Topic))
{
Projects project = new Projects()
{
Topic = model.Topic,
Active = model.Active,
Description = model.Description,
Lecturerid = lecturer.Id,
Subjectid = model.SubjectId,
};
context.Projects.Add(project);
context.SaveChanges();
return(true);
}
errorMessage = PortalMessages.TopicIsUsed;
return(false);
}
}
public async Task <IActionResult> PutLecturers(int id, Lecturers lecturers)
{
if (id != lecturers.LecturerId)
{
return(BadRequest());
}
var result = await _context.Lecturers.FindAsync(id);
result.Name = lecturers.Name;
result.Birthdate = lecturers.Birthdate;
result.PhoneNumber = lecturers.PhoneNumber;
result.Address = lecturers.Address;
result.Email = lecturers.Email;
result.Password = EncryptPassword(lecturers.Password);
try
{
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!LecturersExists(id))
{
return(NotFound());
}
else
{
throw;
}
}
return(NoContent());
}
/// <summary>
/// изтрива конкретния преподавател
/// </summary>
private void DeleteCurrentLecturer(object obj)
{
// изтриване в базата
databaseService.DeleteUser(selectedLecturer);
// изтриване в xml
XDocument doc = XDocument.Load(XmlDatabase.PathSystData);
doc.Descendants("Users")
.Descendants("Lecturer")
.Where(x => (string)x.Element("PersonalNumber") == selectedLecturer.PersonalNumber)
.Remove();
doc.Save(XmlDatabase.PathSystData);
// изтриване от колекцията
CollectionDataService.Instance.Lecturers.Remove(selectedLecturer);
Lecturers.Remove(selectedLecturer);
if (Lecturers.Count < 1)
{
SelectedLectViewModel.FirstName = string.Empty;
SelectedLectViewModel.LastName = string.Empty;
SelectedLectViewModel.PersonalNumber = string.Empty;
SelectedLectViewModel.Gender = string.Empty;
SelectedLectViewModel.Title = string.Empty;
SelectedLectViewModel.Faculty = string.Empty;
SelectedLectViewModel.Region = string.Empty;
SelectedLectViewModel.BirthDate = string.Empty;
Image = null;
}
}
public async Task <ApiReturnValue <Lecturers> > GetLecturer(int pageSize = 100, int pageNumber = 1)
{
ApiReturnValue <Lecturers> apiReturnValue = new ApiReturnValue <Lecturers>();
try
{
Lecturers lecturers = new Lecturers()
{
TotalCount = await GetLecturerCount(),
PageSize = pageSize,
PageNumber = pageNumber,
Rows = await GetListLecturer(pageSize, pageNumber)
};
apiReturnValue.IsSuccess = true;
apiReturnValue.Object = lecturers;
}
catch (Exception e)
{
apiReturnValue.IsSuccess = false;
apiReturnValue.Object = null;
apiReturnValue.Error = new ApiReturnError()
{
displayMessage = "Error - GetLecturer", errorMessage = e.Message
};
}
return(apiReturnValue);
}
public void AddNewLecturer(Lecturers lec, System.Web.UI.WebControls.Label lblAddedBy)
{
try
{
DatabaseConnection DB = new DatabaseConnection();
DB.openConnection();
vLecturerId = lec.txAddLecturerId.Text;
vPassword = lec.txAddLecturerId.Text;
vAuthorityLevel = 2;
vFirstName = lec.txAddFirstName.Text;
vLastName = lec.txAddLastName.Text;
vAddress = lec.txAddAddress.Text;
vContactNo = lec.txAddContactNo.Text;
vDOB = lec.txAddDOB.Text;
vSalary = Convert.ToDouble(lec.txAddSalary.Text);
vEmailAddress = lec.txAddEmail.Text;
vAddedBy = lblAddedBy.Text;
vAddedDateTime = DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss");
string sqlInsertCmd = "INSERT INTO Employees VALUES('" + vLecturerId + "', '" + vPassword + "', '" + vAuthorityLevel + "', '" + vFirstName + "', '" + vLastName + "', '" + vAddress + "', '" + vContactNo + "', '" + vDOB + "', '" + vSalary + "', '" + vEmailAddress + "', '" + vAddedBy + "', '" + vAddedDateTime + "')";
SqlCommand cmd = new SqlCommand(sqlInsertCmd, DatabaseConnection.dbConnection);
cmd.ExecuteNonQuery();
DB.closeConnection();
}
catch (Exception ex)
{
MessageBox.Show("Error" + ex);
}
}
public InstructorModel GetInstructorByUserId(int id)
{
using (SZPNUWContext context = new SZPNUWContext())
{
Lecturers lecturer = context.Lecturers.Include(x => x.User).FirstOrDefault(s => s.User.Id == id);
if (lecturer == null)
{
return(null);
}
InstructorModel model = new InstructorModel
{
Id = lecturer.Id,
Login = lecturer.User.Login,
FirstName = lecturer.User.Firstname,
LastName = lecturer.User.Lastname,
PESEL = lecturer.User.Pesel,
Address = lecturer.User.Address,
City = lecturer.User.City,
Code = lecturer.Code,
DateOfBirth = lecturer.User.Dateofbirth,
UserId = lecturer.Userid,
UserType = (UserTypes)lecturer.User.Usertype,
};
return(model);
}
}
public void UpdateLecturer(Lecturers lec)
{
try
{
DatabaseConnection DB = new DatabaseConnection();
DB.openConnection();
vLecturerId = lec.txUpdateLecturerId.Text;
vFirstName = lec.txUpdateFirstName.Text;
vLastName = lec.txUpdateLastName.Text;
vAddress = lec.txUpdateAddress.Text;
vContactNo = lec.txUpdateContactNo.Text;
vDOB = lec.txUpdateDOB.Text;
vSalary = Convert.ToDouble(lec.txUpdateSalary.Text);
vEmailAddress = lec.txUpdateEmail.Text;
string sqlUpdateCmd = "Update Employees SET firstName = '" + vFirstName + "', lastName = '" + vLastName + "', address = '" + vAddress + "', contactNo = '" + vContactNo + "', DOB = '" + vDOB + "', salary = '" + vSalary + "', emailAddress = '" + vEmailAddress + "' WHERE employeeId = '" + vLecturerId + "'";
SqlCommand cmd = new SqlCommand(sqlUpdateCmd, DatabaseConnection.dbConnection);
cmd.ExecuteNonQuery();
DB.closeConnection();
}
catch (Exception ex)
{
MessageBox.Show("Error" + ex);
}
}
/*
* private ApiReturnValue<Lecturers> MakeReturnValue(bool isSuccess, List<Lecturer> lstLecturer, ApiReturnError error)
* {
* ApiReturnValue<Lecturers> apiReturnValue = new ApiReturnValue<Lecturers>();
*
* apiReturnValue.IsSuccess = isSuccess;
*
* if (isSuccess)
* {
* Lecturers lecturers = new Lecturers() { TotalCount = lstLecturer.Count, PageSize = 0, PageNumber = 1, Rows = lstLecturer };
* apiReturnValue.Object = lecturers;
* }
* else
* {
* apiReturnValue.Object = null;
* apiReturnValue.Error = error;
* }
*
* return apiReturnValue;
* }
*/
public async Task <ApiReturnValue <Lecturers> > GetLecturer(int pageSize = 100, int pageNumber = 1)
{
return(await Task.Run(() =>
{
ApiReturnValue <Lecturers> apiReturnValue = new ApiReturnValue <Lecturers>();
try
{
var lstLecturer = JsonConvert.DeserializeObject <List <Lecturer> >(System.IO.File.ReadAllText(Path.Combine(CurrentDirectory, "Data", "Lecturer.json")));
Lecturers lecturers = new Lecturers();
lecturers.TotalCount = lstLecturer.Count();
lecturers.PageNumber = pageNumber;
lecturers.PageSize = pageSize;
lecturers.Rows = lstLecturer.Skip((pageNumber - 1) * pageSize).Take(pageSize).ToList();
apiReturnValue.IsSuccess = true;
apiReturnValue.Object = lecturers;
}
catch (Exception e)
{
apiReturnValue.IsSuccess = false;
apiReturnValue.Object = null;
apiReturnValue.Error.displayMessage = "";
apiReturnValue.Error.errorMessage = e.Message;
}
return apiReturnValue;
}));
}
public async Task <ApiReturnValue <Lecturers> > GetLecturer(string lecturerName)
{
return(await Task.Run(() =>
{
ApiReturnValue <Lecturers> apiReturnValue = new ApiReturnValue <Lecturers>();
try
{
var lstLecturer = JsonConvert.DeserializeObject <List <Lecturer> >(System.IO.File.ReadAllText(Path.Combine(CurrentDirectory, "Data", "Lecturer.json")));
//List<Lecturer> lstLecturer = new List<Lecturer>();
Lecturers lecturers = new Lecturers();
lecturers.TotalCount = 70;
lecturers.PageNumber = 1;
lecturers.PageSize = 20;
lecturers.Rows = lstLecturer;
apiReturnValue.IsSuccess = true;
apiReturnValue.Object = lecturers;
}
catch (Exception e)
{
apiReturnValue.IsSuccess = false;
}
return apiReturnValue;
}));
}
private void HandleReviews()
{
var root = this.xDoc.Root;
var courses = Courses.Get();
foreach (var course in courses.Where(x => x.Reviews.Count > 0))
{
root.Add(
new XElement(ns + "url",
new XElement(ns + "loc", string.Concat(baseURL, "Review/Course/", course.Id)),
new XElement(ns + "priority", "0.5"),
new XElement(ns + "changefreq", "daily")
)
);
}
var lecturers = Lecturers.Get(true);
foreach (var lecturer in lecturers.Where(x => x.Reviews.Count > 0))
{
root.Add(
new XElement(ns + "url",
new XElement(ns + "loc", string.Concat(baseURL, "Review/Lecturer/", lecturer.Id)),
new XElement(ns + "priority", "0.5"),
new XElement(ns + "changefreq", "daily")
)
);
}
}
public bool UpdateProject(ProjectModel model, ref string errorMessage)
{
using (SZPNUWContext context = new SZPNUWContext())
{
Lecturers lecturer = context.Lecturers.FirstOrDefault(x => x.Userid == model.UserId);
if (lecturer == null)
{
errorMessage = PortalMessages.UserDoesNotExist;
return(false);
}
if (!context.Projects.Any(x => x.Topic == model.Topic && x.Id != model.Id))
{
Projects project = context.Projects.FirstOrDefault(x => x.Id == model.Id);
if (project != null)
{
project.Topic = model.Topic;
project.Active = model.Active;
project.Description = model.Description;
project.Lecturerid = lecturer.Id;
project.Subjectid = model.SubjectId;
context.SaveChanges();
return(true);
}
errorMessage = PortalMessages.NoSuchElement;
return(false);
}
errorMessage = PortalMessages.TopicIsUsed;
return(false);
}
}
private void DeleteCurrentLecturer(object obj)
{
var view = CollectionViewSource.GetDefaultView(Lecturers);
LecturerModel selectedLecturer = view.CurrentItem as LecturerModel;
Lecturers.Remove(selectedLecturer);
}
public async Task <IActionResult> Edit(int id, [Bind("Id,Name,Surname,Age,Salary")] Lecturers lecturer)
{
if (ModelState.IsValid)
{
await _lecturersService.Update(id);
return(RedirectToAction(nameof(Index)));
}
return(View(lecturer));
}
public ActionResult AssignLecture(int lecID, int acaID)
{
Lecturers new_lec = new Lecturers();
new_lec.UserID = acaID;
new_lec.LecID = lecID;
db.Lecturers.Add(new_lec);
db.SaveChanges();
return(RedirectToAction("AssignLecture", "User"));
}
public void RemoveLecturer(Lecturer lecturer)
{
Lecturers.Remove(lecturer);
foreach (var classRecord in ClassRecords)
{
if (classRecord.Lecturer == lecturer)
{
classRecord.Lecturer = null;
}
}
}
public async Task <ActionResult <Lecturers> > PostLecturers(Lecturers lecturers)
{
var result = await _context.Lecturers
.Where(l => l.Email == lecturers.Email)
.FirstOrDefaultAsync();
if (result != null)
{
return(Conflict("Email has been used"));
}
lecturers.Password = EncryptPassword(lecturers.Password);
_context.Lecturers.Add(lecturers);
await _context.SaveChangesAsync();
return(CreatedAtAction("GetLecturers", new { id = lecturers.LecturerId }, lecturers));
}
public async Task <ApiReturnValue <Lecturers> > GetLecturer(string lecturerName)
{
ApiReturnValue <Lecturers> apiReturnValue = new ApiReturnValue <Lecturers>();
var lstLecturer = await GetLecturerById(lecturerName);
Lecturers lecturers = new Lecturers();
lecturers.TotalCount = 70;
lecturers.PageNumber = 1;
lecturers.PageSize = 20;
lecturers.Rows = lstLecturer;
apiReturnValue.IsSuccess = true;
apiReturnValue.Object = lecturers;
await Task.Delay(1000);
return(apiReturnValue);
}
private void HandleLecturers()
{
var root = this.xDoc.Root;
root.Add(
new XElement(ns + "url",
new XElement(ns + "loc", string.Concat(baseURL, "Lecturer/Register")),
new XElement(ns + "priority", "0.5"),
new XElement(ns + "changefreq", "weekly")
)
);
root.Add(
new XElement(ns + "url",
new XElement(ns + "loc", string.Concat(baseURL, "Lecturer/Login")),
new XElement(ns + "priority", "0.5"),
new XElement(ns + "changefreq", "weekly")
)
);
root.Add(
new XElement(ns + "url",
new XElement(ns + "loc", string.Concat(baseURL, "Search/Lecturers")),
new XElement(ns + "priority", "1.0"),
new XElement(ns + "changefreq", "daily")
)
);
var lecturers = Lecturers.Get(true);
foreach (var lecturer in lecturers)
{
root.Add(
new XElement(ns + "url",
new XElement(ns + "loc", string.Concat(baseURL, "Lecturer/", lecturer.Id)),
new XElement(ns + "priority", "1.0"),
new XElement(ns + "changefreq", "daily")
)
);
}
}
public bool UpdateInstructor(InstructorModel model, ref string errorMessage)
{
using (SZPNUWContext context = new SZPNUWContext())
{
Lecturers lecturer = context.Lecturers.Include(x => x.User).FirstOrDefault(p => p.Id == model.Id);
if (lecturer != null)
{
lecturer.User.Firstname = model.FirstName;
lecturer.User.Lastname = model.LastName;
lecturer.User.Pesel = model.PESEL;
lecturer.User.Address = model.Address;
lecturer.User.City = model.City;
lecturer.Code = model.Code;
lecturer.User.Dateofbirth = model.DateOfBirth;
context.SaveChanges();
return(true);
}
errorMessage = PortalMessages.NoSuchElement;
return(false);
}
}
public bool RegisterInstructor(InstructorModel model, ref string errorMessage)
{
using (SZPNUWContext context = new SZPNUWContext())
{
if (!context.Users.Where(x => x.Login == model.Login).Any())
{
if (!context.Lecturers.Where(x => x.Code == model.Code).Any())
{
using (var transaction = context.Database.BeginTransaction())
{
Users user = new Users {
Login = model.Login, Password = SecurityService.GetSHA256Hash(model.Password), Firstname = model.FirstName, Lastname = model.LastName, Pesel = model.PESEL, City = model.City, Address = model.Address, Dateofbirth = model.DateOfBirth, Usertype = (int)UserTypes.Instructor
};
Lecturers lecturer = new Lecturers {
Code = model.Code
};
user.Lecturers = lecturer;
try
{
context.Add(user);
context.SaveChanges();
transaction.Commit();
}
catch (Exception)
{
transaction.Rollback();
errorMessage = PortalMessages.InsertDBError;
}
}
return(true);
}
}
errorMessage = ValidationMessages.UsedLogin;
return(false);
}
}
public async Task <ActionResult <Lecturers> > Login(Lecturers lecturers)
{
var result = await _context.Lecturers.FirstOrDefaultAsync(l => l.Email == lecturers.Email);
if (result == null)
{
return(Unauthorized("The email or password is incorrect"));
}
var validationStatus = VerifyPassword(lecturers.Password, result.Password);
if (!validationStatus)
{
return(Unauthorized("The email or password is incorrect"));
}
result.LastLogin = DateTime.Now;
result.Status = true;
await _context.SaveChangesAsync();
var filtered = new
{
result.LecturerId,
result.Name,
result.Birthdate,
result.PhoneNumber,
result.Address,
result.Email,
result.LastLogin,
result.Status,
result.CreatedDate,
result.UpdatedDate
};
return(Ok(filtered));
}
public void Update(Lecturers lecturers)
{
}
public void Insert(Lecturers lecturers)
{
context.Lecturers.Add(lecturers);
}
public void Delete(Lecturers lecturers)
{
context.Lecturers.Remove(lecturers);
}
public bool Equals(TimetableEvent other)
{
if (other is null)
{
return(false);
}
if (Department != other.Department)
{
return(false);
}
if (FieldOfStudy != other.FieldOfStudy)
{
return(false);
}
if (Mode != other.Mode)
{
return(false);
}
if (Year != other.Year)
{
return(false);
}
if (Semester != other.Semester)
{
return(false);
}
if (IsFaculty != other.IsFaculty)
{
return(false);
}
if (FacultyGroup != other.FacultyGroup)
{
return(false);
}
if (Degree != other.Degree)
{
return(false);
}
if (Name != other.Name)
{
return(false);
}
if (DayOfWeek != other.DayOfWeek)
{
return(false);
}
if (StartTime != other.StartTime)
{
return(false);
}
if (EndTime != other.EndTime)
{
return(false);
}
if (Building != other.Building)
{
return(false);
}
if (Room != other.Room)
{
return(false);
}
if (!Lecturers.SetEquals(other.Lecturers))
{
return(false);
}
if (Type != other.Type)
{
return(false);
}
if (Remarks != other.Remarks)
{
return(false);
}
if (AcademicYear != other.AcademicYear)
{
return(false);
}
return(true);
}
public void AddLecturer(Lecturer lecturer)
{
Lecturers.Add(lecturer);
}
public async Task Add(Lecturers lecturer)
{
_genericRepository.Add(lecturer);
await _genericRepository.Save();
}
static async Task Main(string[] args)
{
Console.WriteLine("------------------Mutable------------------------");
//Values are mutable
int x = 10;
x = 20;
x = 30;
x = 50;
Console.WriteLine(x);
Console.WriteLine("------------------Dynamically implemented properties------------------------");
Students student = new Students("James", 18, "21/ug-223/BSCS", 3000);
//age mutable
student.age = 28;
//name is readyOnly(immutable); cannot rewrite
//student.name="Job";
//regNo is mutable
student.regNo = "21/ug-335/BSSE-S";
student.tution = 7000;
Console.WriteLine(student.name);
Console.WriteLine(student.age);
Console.WriteLine(student.regNo);
Console.WriteLine(student.tution);
Console.WriteLine("------------------Implicity typing------------------------");
var scores = new[] { 1, 2.5, 3, 4, 5 };
foreach (double element in scores)
{
Console.WriteLine(element);
}
Console.WriteLine("------------------Object and collactions initializers------------------------");
Products phone = new Products {
pPrice = 3000, pName = "Smart Phone", pQuantity = 20, pBrand = "Oppo"
};
phone = new Products();
Console.WriteLine(phone.pName + "" + phone.pPrice);
// List<Products> products = new List<Products>{
// new Products { pPrice = 3000, pName = "Smart Phone", pQuantity = 20, pBrand = "Oppo" },
// new Products { pPrice = 6000, pName = "Smart Tv", pQuantity = 10, pBrand = "Samsung" } ,
// new Products { pPrice = 4000, pName = "Fridge", pQuantity = 5, pBrand = "LG" },
// new Products { pPrice = 5000, pName = "Oven", pQuantity = 2, pBrand = "LG" },
// };
GetProductsDelegate productsDelegate = new GetProductsDelegate(getProducts);
List <Products> products = productsDelegate.Invoke();
Console.WriteLine("------------------Lambda expression ------------------------");
//Lambda expression
//Lambda calculus
//Anything coming after the arrow funtion, should be condition.
List <Products> hightPrices = products.FindAll(value => value.pPrice < 4000);
foreach (Products product in hightPrices)
{
Console.WriteLine(product.pName + " " + product.pPrice);
}
Console.WriteLine("------------------LINQ Expression queries------------------------");
//
IEnumerable <Products> lowPrices =
from product in products where product.pPrice < 5000 orderby product.pName ascending select product;
foreach (Products product in lowPrices)
{
Console.WriteLine(product.pName + " " + product.pPrice);
}
Console.WriteLine("------------------ANONYMOUS DATATYPE------------------------");
// Example in Js
/*
* Example in Js
* var user={
* fristname:'',
* lastname:'',
* nationality:'',
* }
*/
// Example in C#
var user = new
{
firstname = "Victor",
lastname = "Manakana",
nationality = "SA"
};
Console.WriteLine(user.firstname);
Console.WriteLine(user.lastname);
Console.WriteLine(user.nationality);
//Dynamic
Console.WriteLine("--------------------------dynamic typing ----------------------------");
Calculator <double> calculator = new Calculator <double>();
dynamic sum = calculator.sum(10.9, 12.9);
Console.WriteLine("Sum is" + sum);
//Optional parameters
Console.WriteLine("--------------------------Optional parameters ----------------------------");
Lecturers lecturers = new Lecturers(200.0);
Console.WriteLine("Sum is: " + lecturers.name + " " + lecturers.wages);
Lecturers lecturers2 = new Lecturers(name: "James", wages: 200.0);
//Asynchronous
Console.WriteLine("--------------------------Asynchronous----------------------------");
// synchronization , asynchronization
// T1 & T2, waits for t1 to finish
// OS dictionary
Program program = new Program();
await program.checkin();
await fetchUserData();
await fetchResultsData();
//Asynchronous Pending tasks
Console.WriteLine("--------------------------Moving next within Pending tasks----------------------------");
IAsyncEnumerator <int> asyncEnumerator = pendingTasks(1, 4).GetAsyncEnumerator();
while (await asyncEnumerator.MoveNextAsync())
{
Console.WriteLine($"Current task value is :{asyncEnumerator.Current}");
}
//Tasks, threads, Jobs
Console.WriteLine("--------------------------Custom task types revisited----------------------------");
// Thread thread= new Thread(new ThreadStart(thread1));
// thread.Start();
// await doPurchaseJob1();
//Run multiple tasks at the same time
//Tasks, threads, Jobs
Console.WriteLine("--------------------------Run multiple tasks at the same time----------------------------");
List <Task> tasks = new List <Task>();
tasks.Add(Task.Run(async() => {
await Task.Delay(1000);
Console.WriteLine("Task1");
}));
tasks.Add(Task.Run(async() => {
await Task.Delay(2000);
Console.WriteLine("Task2");
}));
tasks.Add(Task.Run(async() => {
//await Task.Delay(3000);
await fetchUserData();
Console.WriteLine("Task3");
}));
tasks.Add(Task.Run(async() => {
await Task.Delay(2000);
Console.WriteLine("Task4");
}));
// Task.WaitAll(tasks.ToArray());
//Convariance and contravariance
Console.WriteLine("-------------------------------------Convariance and contravariance------------------------------");
//------------contravariance
// Cow cow= new Mammars();
Mammars mammars = new Cow();
// Mammars mammars1= new Animal();
Animal animal = new Mammars();
//------------convariance
IEnumerable <Animal> animals = new List <Mammars>();
//out , in
//SmartPhone<PhoneTypes> smartPhones= new List<IApple>();
Console.WriteLine("-------------------------------------Convariance and contravariance------------------------------");
string studentDetails = String.Format(" Hey Mr {0} and {1}", "James", "John");
long workerId = 11100000;
string workerDetails = String.Format(" Hey My ID is {0}", workerId);
// Decimal
//double x= 30.00000000000000000000000000000000E25;
Decimal wages = 5000000000000000.50m;
//5,000,000,000,000,000
string engineerWages = String.Format("James wages is {0:N0}", wages);
Console.WriteLine(studentDetails);
Console.WriteLine(wages);
String[] students = { "Victor", "Faith", "Khoza" };
Decimal[] marks = new Decimal[] { 80000000, 8000000, 90000000 };
String[] positions = new String[] { "Senior softwareEng ", "Senior softwareEng", "Senior softwareEng" };
var stringBuilder = new System.Text.StringBuilder();
stringBuilder.Append(String.Format("{0,5} {1,8} {2,7} \n\n", "Engineers", "Salary", "Position"));
for (int i = 0; i < students.Length; i++)
{
stringBuilder.Append(String.Format("{0,5} {1,8:N0} {2,7} \n\n", students[i], marks[i], positions[i]));
}
Console.WriteLine(stringBuilder);
}
