It is very easy to work with communications in the .NET API.

Below are the basic code sample to show how to create either an appointment or a new task.

Note: The CreateAppointment() and CreateTask() require you to reference both the WebObject and Data namespaces.

Create an Appointment

CommunicationEntity newAppointment = CreateAppointment();
newAppointment.AddUser(CurrentUser.UserId);
newAppointment.SetField("comm_action", "Meeting");
newAppointment.SetField("comm_note", "This is an example task");
newAppointment.SaveChanges();

Create a Task

CommunicationEntity newTask = CreateTask();
newTask.AddUser(CurrentUser.UserId);
newTask.SetField("comm_action", "ToDo");
newTask.SetField("comm_note", "This is an example task");
newTask.SaveChanges();

A link to a parental cases or opportunity is easy as these are just fields in the main communication table ad can be added using

newTask.SetField("comm_opportunity",int.Parse(GetContextInfo("opportunity", "oppo_opportunityid"));

The detail of the user is added to the comm_link table.

BUT links to the company and person actual belong to the communication link table. If you want to link the newly create Appointment or Task to a company or person then you code will need to update the comm_link record that is implicitly created.

An example is show below

using Sage.CRM.WebObject;
using Sage.CRM.Data;
 
namespace Create_Task
{
public class MyCustomPage : Web
{
public override void BuildContents()
{
CommunicationEntity newTask = CreateTask();
newTask.AddUser(CurrentUser.UserId);
 
newTask.SetField("comm_channelid",CurrentUser.TeamId);
newTask.SetField("comm_action", "ToDo");
newTask.SetField("comm_note", "This is an example task");
newTask.SetField("comm_subject", "This is an example task");
 
newTask.SaveChanges();
 
int companyID = int.Parse(GetContextInfo("company", "comp_companyid"));
Record commlinkRecord = FindRecord("comm_link", "CmLi_Comm_CommunicationId="+newTask.RecordId);//parameters as string values
commlinkRecord.SetField("cmli_comm_companyid", companyID);
commlinkRecord.SaveChanges();
}
}
}

Once the newTask.SaveChanges method is called the unique ID of the communication record can be found and it can be used to retrieve the corresponding comm_link record. This can then be updated.