Create MS Project Files in C#

add-calendar-in-project.cs

// Create a project instance
Project project = new Project();

// Define Calendar
Calendar cal = project.Calendars.Add("Calendar1");

// Add working days monday through thursday with default timings
cal.WeekDays.Add(WeekDay.CreateDefaultWorkingDay(DayType.Monday));
cal.WeekDays.Add(WeekDay.CreateDefaultWorkingDay(DayType.Tuesday));
cal.WeekDays.Add(WeekDay.CreateDefaultWorkingDay(DayType.Wednesday));
cal.WeekDays.Add(WeekDay.CreateDefaultWorkingDay(DayType.Thursday));
cal.WeekDays.Add(new WeekDay(DayType.Saturday));
cal.WeekDays.Add(new WeekDay(DayType.Sunday));

// Set friday as short working day
WeekDay myWeekDay = new WeekDay(DayType.Friday);

// Sets working time. Only time part of DateTime is important
WorkingTime wt1 = new WorkingTime();
wt1.FromTime = new DateTime(1, 1, 1, 9, 0, 0, 0);
wt1.ToTime = new DateTime(1, 1, 1, 12, 0, 0, 0);
WorkingTime wt2 = new WorkingTime();
wt2.FromTime = new DateTime(1, 1, 1, 13, 0, 0, 0);
wt2.ToTime = new DateTime(1, 1, 1, 16, 0, 0, 0);
myWeekDay.WorkingTimes.Add(wt1);
myWeekDay.WorkingTimes.Add(wt2);
myWeekDay.DayWorking = true;
cal.WeekDays.Add(myWeekDay);

// Save project
project.Save("Project_DefineCalendarWeekdays_out.xml", SaveFileFormat.XML);

add-resources.cs

// Create project
Project project = new Project();

// Add resources
Resource resource = project.Resources.Add("Rsc");

// Save project
project.Save("CreateResources_out.xml", SaveFileFormat.XML);

add-task-properties.cs

// Create project
Project project = new Project();

// Add task and set task properties
Task task = project.RootTask.Children.Add("Task1");
task.Set(Tsk.Start, project.RootTask.Get(Tsk.Start).AddDays(1));
task.Set(Tsk.Name, "new name");

assign-tasks-to-resources.cs

// Create project
Project project = new Project("New Project.mpp")
{
    CalculationMode = CalculationMode.Automatic
};

// Set properties
project.Set(Prj.DateFormat, DateFormat.DateDddMmDdYy);
project.Set(Prj.StartDate, new DateTime(2019, 9, 16, 9, 0, 0));
project.Set(Prj.NewTasksAreManual, false);
project.Set(Prj.ActualsInSync, false);

// Add resources
Resource workResource = project.Resources.Add("Servente (Work)");
workResource.Set(Rsc.Name, "Servente (Work)");
workResource.Set(Rsc.Initials, "S");
workResource.Set(Rsc.Type, ResourceType.Work);
workResource.Set(Rsc.StandardRateFormat, RateFormatType.Hour);
workResource.Set(Rsc.Code, "1503");

Resource materialResource = project.Resources.Add("Tijolo (Material)");
materialResource.Set(Rsc.Name, "Tijolo (Material)");
materialResource.Set(Rsc.Initials, "T");
materialResource.Set(Rsc.Type, ResourceType.Material);
materialResource.Set(Rsc.StandardRateFormat, RateFormatType.MaterialResourceRate);
materialResource.Set(Rsc.Code, "21341");

// Add tasks
Task task1 = project.RootTask.Children.Add("Task - 01");
task1.Set(Tsk.IsRollup, new NullableBool(true));
task1.Set(Tsk.IsPublished, new NullableBool(false));
Task task2 = task1.Children.Add("Task - 01.01");
task2.Set(Tsk.IsRollup, new NullableBool(true));
task2.Set(Tsk.IsPublished, new NullableBool(false));
Task task3 = task2.Children.Add("Task - 01.01.001");
task3.Set(Tsk.IsEstimated, new NullableBool(false));
task3.Set(Tsk.Start, new DateTime(2019, 9, 16, 9, 0, 0));
task3.Set(Tsk.Duration, project.GetDuration(10, TimeUnitType.Day));
task3.Set(Tsk.Work, project.GetDuration(10, TimeUnitType.Day));
task3.Set(Tsk.IsRollup, new NullableBool(true));
task3.Set(Tsk.IsPublished, new NullableBool(false));

// Assign tasks
ResourceAssignment assignment1 = project.ResourceAssignments.Add(task3, materialResource);
assignment1.Set(Asn.Delay, project.GetDuration(40, TimeUnitType.Hour));
assignment1.Set(Asn.Start, new DateTime(2019, 9, 23, 9, 0, 0));
assignment1.Set(Asn.Finish, new DateTime(2019, 9, 27, 18, 0, 0));
ResourceAssignment assignment2 = project.ResourceAssignments.Add(task3, workResource);
assignment2.Set(Asn.Work, project.GetDuration(56, TimeUnitType.Hour));
assignment2.Set(Asn.Start, new DateTime(2019, 9, 16, 9, 0, 0));
assignment2.Set(Asn.Finish, new DateTime(2019, 9, 24, 18, 0, 0));

// to match expected MPP fully
assignment2.Set(Asn.WorkContour, WorkContourType.Contoured);
task3.Set(Tsk.IsManual, new NullableBool(true));
task1.Set(Tsk.IsManual, new NullableBool(true));

// Save project
project.Save("Assignment_Dates.mpp", SaveFileFormat.MPP);

create-mpp-file.cs

// Create a new project
Project project = new Project();

// Save it as .mpp file
project.Save("New Project.mpp", SaveFileFormat.MPP);

create-tasks.cs

// Create a new project
Project project = new Project();

// Add task and sub task
Task task = project.RootTask.Children.Add("Summary1");
Task subtask = task.Children.Add("Subtask1");

// Save file
project.Save("CreateTasks_out.xml", SaveFileFormat.XML);

create-xml-file.cs

// Create a new project
Project project = new Project();

// Save it as .xml file
project.Save("EmptyProjectSaveXML_out.xml", SaveFileFormat.XML);

set-resource-properties.cs

// Create project
Project project = new Project();

// Add resources
Resource resource = project.Resources.Add("Rsc");

// Save project
project.Save("CreateResources_out.xml", SaveFileFormat.XML);