private void EditAction(object obj)
        {
            var form = new Views.Pages.TambahMahasiswaView(SelectedItem.Clone() as Mahasiswa);

            form.ShowDialog();
            var viewmodel = form.DataContext as TambahMahasiswaViewModel;

            if (viewmodel != null && viewmodel.Model != null)
            {
                var result = DataSource.Where(x => x.IDMahasiswa == SelectedItem.IDMahasiswa).FirstOrDefault();
                if (result != null)
                {
                    result.IdJurusan      = viewmodel.Model.IdJurusan;
                    result.Jurusan        = viewmodel.Jurusan;
                    result.Gelombang      = viewmodel.Model.Gelombang;
                    result.HasilTest      = viewmodel.Model.HasilTest;
                    result.IdProgdi       = viewmodel.Model.IdProgdi;
                    result.IPK            = viewmodel.Model.IPK;
                    result.MasaStudi      = viewmodel.Model.MasaStudi;
                    result.NPM            = viewmodel.Model.NPM;
                    result.Suku           = viewmodel.Model.Suku;
                    result.Nama           = viewmodel.Model.Nama;
                    result.GelombangModel = viewmodel.Model.GelombangModel;
                }
                Source.Refresh();
            }
        }
        private void AddNewItemaction(object obj)
        {
            var form = new Views.Pages.TambahMahasiswaView(SelectedProgdi);

            form.ShowDialog();
            var viewmodel = form.DataContext as TambahMahasiswaViewModel;

            if (viewmodel != null && viewmodel.Model != null)
            {
                viewmodel.Model.Nomor = DataSource.Count + 1;
                DataSource.Add(viewmodel.Model);
                Source.Refresh();
            }
        }