WPF Datagrid set selected row

Question

How do I use the Datagrid.SelectedItem to select a row programmatically?

Do I first have to create a IEnumerable of DataGridRow

Answer 1

It's a little trickier to do what you're trying to do than I'd prefer, but that's because you don't really directly bind a DataGrid to a DataTable.

When you bind DataGrid.ItemsSource to a DataTable, you're really binding it to the default DataView, not to the table itself. This is why, for instance, you don't have to do anything to make a DataGrid sort rows when you click on a column header - that functionality's baked into DataView, and DataGrid knows how to access it (through the IBindingList interface).

The DataView implements IEnumerable (more or less), and the DataGrid fills its items by iterating over this. This means that when you've bound DataGrid.ItemsSource to a DataTable, its SelectedItem property will be a DataRowView, not a DataRow.

If you know all this, it's pretty straightforward to build a wrapper class that lets you expose properties that you can bind to. There are three key properties:

• Table, the DataTable,
• Row, a two-way bindable property of type DataRowView, and
• SearchText, a string property that, when it's set, will find the first matching DataRowView in the table's default view, set the Row property, and raise PropertyChanged.

It looks like this:

public class DataTableWrapper : INotifyPropertyChanged
{
    private DataRowView _Row;

    private string _SearchText;

    public DataTableWrapper()
    {
        // using a parameterless constructor lets you create it directly in XAML
        DataTable t = new DataTable();
        t.Columns.Add("id", typeof (int));
        t.Columns.Add("text", typeof (string));

        // let's acquire some sample data
        t.Rows.Add(new object[] { 1, "Tower"});
        t.Rows.Add(new object[] { 2, "Luxor" });
        t.Rows.Add(new object[] { 3, "American" });
        t.Rows.Add(new object[] { 4, "Festival" });
        t.Rows.Add(new object[] { 5, "Worldwide" });
        t.Rows.Add(new object[] { 6, "Continental" });
        t.Rows.Add(new object[] { 7, "Imperial" });

        Table = t;

    }

    // you should have this defined as a code snippet if you work with WPF
    private void OnPropertyChanged(string propertyName)
    {
        PropertyChangedEventHandler h = PropertyChanged;
        if (h != null)
        {
            h(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    // SelectedItem gets bound to this two-way
    public DataRowView Row
    {
        get { return _Row; }
        set
        {
            if (_Row != value)
            {
                _Row = value;
                OnPropertyChanged("Row");
            }
        }
    }

    // the search TextBox is bound two-way to this
    public string SearchText
    {
        get { return _SearchText; }
        set
        {
            if (_SearchText != value)
            {
                _SearchText = value;
                Row = Table.DefaultView.OfType()
                    .Where(x => x.Row.Field("text").Contains(_SearchText))
                    .FirstOrDefault();
            }
        }
    }

    public DataTable Table { get; private set; }
}

And here's XAML that uses it:

    
        
    
    
        
        
                
                
            
            Text