//Searches the Librari for Items by numerous parameters
//and display the results in the DataGrid
private void MultipleSearch()
{
//Base Category parameter (nullable)
//the default value is true for using it in predicate
//if User haven't choose the Base Category
eBaseCategory?eBase =
cmbBaseCategory.SelectedValue is eBaseCategory ?
(eBaseCategory?)cmbBaseCategory.SelectedValue : null;
//Inner Category parameter (nullable)
//the default value is true for using it in predicate
//if User haven't choose the Inner Category
eInnerCategory?eInner =
cmbInnerCategory.SelectedValue is eInnerCategory ?
(eInnerCategory?)cmbInnerCategory.SelectedValue : null;
//Make Multiply Search by numerous parameters
//and display the results in the DataGrid
dataLib.ItemsSource = mainLibrary.MultiSearch(eBase, eInner, txtName.Text);
}
