Binding class with master/detail into two datagridview

Question

I had made a class in C# Windows form to represent my database. It has a master/detail using List<>

A record with Employee profile with Trainings(master) and TrainingDetails(detail)

Now, how can I display this into 2 datagridview that whenever I select a "Training" from the first datagridview it will display the details on the 2nd datagridview.

Its easy to change the datasource of the 2nd datagridview whenever the user select a new item from the first datagridview. But im wondering how it is done professionally.

Also saving is a pain, Im thingking to iterate through the datarow and save it but It mean I have to know what are the data has been update, inserted and deleted.

Please help me. Im a newbie.

dont forget to mark answer as accepted if you got the info you want.. — Pranay Rana

David Hall David Hall · Accepted Answer · 2012-06-02T14:42:50

BindingSources take care of this for you.

For example say I have two classes, Teachers and Students:

public class Teacher
{
    private List<Student> _students = new List<Student>();
    public string Name { get; set; }
    public string Class { get; set; }
    public List<Student> Students { get { return _students; } }
}

public class Student
{
    public string Name { get; set; }
    public int Age { get; set; }
}

You can then create a list of Teachers which represents the Master/Detail situation:

List<Teacher> teachers = new List<Teacher>();
Teacher t = new Teacher();
t.Name = "Mr. Smith";
t.Class = "A1";
teachers.Add(t);

Student s = new Student();
s.Name = "Jimmy Jones";
s.Age = 6;            
t.Students.Add(s);

s = new Student();
s.Name = "Jane Doe";
s.Age = 5;
t.Students.Add(s);

t = new Teacher();
t.Name = "Ms. Allen";
t.Class = "B3";
teachers.Add(t);

s = new Student();
s.Name = "Sally Student";
s.Age = 7;
t.Students.Add(s);

On my form I have two DataGridViews, teachersDataGridView and studentsDataGridView and two binding sources teachersBindingSource and studentsBindingSource.

I wire everything up like so:

    teachersBindingSource.DataSource = teachers;

    studentsBindingSource.DataSource = teachersBindingSource;
    studentsBindingSource.DataMember = "Students";

    teachersDataGridView.DataSource = teachersBindingSource;
    studentsDataGridView.DataSource = studentsBindingSource;

And as if by magic when running up on the form selecting an item from the teachers grid changes students grid.

For managing inserts, updates and deletes you will need to implement some sort of change tracking yourself (or use an ORM such as Entity Framework or nHibernate). It is a topic that deserves its own question so read up on those technologies (and look at the blog post I like below) and come back when you have some specific problems.

For this answer I borrowed heavily from this excellent post - the example I've given is complete and avoids a lot of the complexity in that authors example's, but eventually you will probably want to at least know about everything he discusses. Download his demos and have a look.

Binding class with master/detail into two datagridview

1 Answers