Design Question: CollectionView for each Object?

Question

Hello, I'm wondering how you guys would solve this problem. I have following class

public class MyTask 
{
    public int CustomerID { get; set; }
    public int ProjectID { get; set; }
}

public List<Project> AllProjects { get; set; }
public class Project 
{
    public string ProjectName { get; set; }
    public int CustomerID { get; set; }
}

Now at program-start, I load all available Projects into "AllProjects". Then I bind the Collection to a ComboBox, where a User first has to enter the CustomerID and depending on that, the ComboBox for Projects changes. What's in your opinion the best way to do that? Using a CollectionView for each MyTask?

What I'm doing right now is have in MyTask a List AvailableProjects, which gets changed each time when the MyTask.CustomerID is changed.. e.g.

public int CustomerID { 
    get { return _customerID; }
    set { _customerID = value; UpdateAvailableProjects(); }
}
private void UpdateAvailableProjects()
{
   //Loop trough static.Main.AllProjects and check if Project.CustomerID == this.CustomerID); 
}

Thanks for any help.

Cheers

Answer 1

Why not make a class Customer and from there get all associated projects which can then be loaded in the combo.

public class Customer
{
    private int customerId = 0;
    public int CustomerId
    {
        get
        {
            return customerId;
        }
        set
        {
            customerId = value;
        }
    }

    public List<Project> availableProjects
    {
        get
        {
            return getCustomerRelatedProjects();
        }
    }

    //you change the accessor here according to the needs
    private List<Project> getCustomerRelatedProjects()
    {
        //do the processing here for Database hit or from the list you load at the program load etc.
        return new List<Project>();
    }

}

public class Project 
{
    int projectId = 0;

    public int ProjectId
    {
        get
        {
            return projectId;
        }
        set
        {
            projectId = value;
        }
    }

    string projName = string.Empty;
    public string ProjectName
    {
        get
        {
            return projName;
        }
        set
        {
            projName = value;
        }
    }
}