c# - Filter a DataGrid in WPF

Question

I load a lists of objects in a datagrid with this:

dataGrid1.Items.Add(model);

The model become data from a database. It has a Id(int), Name(string) and Text(string)

In my datagrid I show only the Name of the model. How can I filter the datagrid now, when I enter something in a textbox?

I was at this page: http://msdn.microsoft.com/en-us/library/vstudio/ff407126(v=vs.100).aspx but I don't understand the code from there and I can not explain how I should transpose that for my problem.

Answer 1

there are multiple way's to filter Collection

let's suggesting this is your Item Class

public class Model
{
    public string Name
    {
        get;
        set;
    }
}

and your collection looks like

       var ObColl = new ObservableCollection<Model>();

        ObColl.Add(new Model() { Name = "John" });
        ObColl.Add(new Model() { Name = "Karl" });
        ObColl.Add(new Model() { Name = "Max" });
        ObColl.Add(new Model() { Name = "Mary" });

Way 1 (Predicate):

    public MainWindow()
    {
        InitializeComponent();

        // Collection which will take your ObservableCollection
        var _itemSourceList = new CollectionViewSource() { Source = ObColl };

        // ICollectionView the View/UI part 
        ICollectionView Itemlist = _itemSourceList.View;

        // your Filter
        var yourCostumFilter= new Predicate<object>(item => ((Model)item).Name.Contains("Max"));

        //now we add our Filter
        Itemlist.Filter = yourCostumFilter;

        dataGrid1.ItemsSource = Itemlist;
    }

Way 2 (FilterEventHandler):

    public MainWindow()
    {
        InitializeComponent();

        // Collection which will take your Filter
        var _itemSourceList = new CollectionViewSource() { Source = ObColl };

       //now we add our Filter
       _itemSourceList.Filter += new FilterEventHandler(yourFilter);

        // ICollectionView the View/UI part 
        ICollectionView Itemlist = _itemSourceList.View;

        dataGrid1.ItemsSource = Itemlist;
    }

    private void yourFilter(object sender, FilterEventArgs e)
    {
        var obj = e.Item as Model;
        if (obj != null)
        {
            if (obj.Name.Contains("Max"))
                e.Accepted = true;
            else
                e.Accepted = false;
        }
    }

extended Information to Way 1

if need multiple conditions or some complex Filter you can add a method to your Predicat

    // your Filter
    var yourComplexFilter= new Predicate<object>(ComplexFilter);

    private bool ComplexFilter(object obj)
    {
        //your logic
    }