Question

This one has me beat;

I have a WPF window with two (important for this case) controls, both from the WPF toolkit available at CodePlex; A DatePicker and a DataGrid.

The DataContext of this window is set to a CLR object that has all the information it needs. This CLR object has a large list of data, and a method called GetDataForDate( DateTime date ) which decides which date we will see data for.

How can I create a ObjectDataProvider (which I assume will be the correct solution) that the datagrid can bind to, which provides access to the data returned by GetDataForDate() called with the selected date of the DatePicker as the parameter?

In other words, I want the user to use the datepicker to choose a date, and the grid should automatically update whenever the date is changed to reflect the correct data.

What kind of black magic do I have to do to achieve something like this – which I would guess should be a relatively common databinding scenario?

Thanks in advance!

Answer 1

Here is my complete code. I hope this will help.

The xaml code:

<Window x:Class='DataGridSort.Window1'     xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'     xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'     xmlns:dg='clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit'     xmlns:System='clr-namespace:System;assembly=mscorlib'     Title='Window1' Height='413' Width='727'         x:Name='_this'>     <Window.Resources>         <ObjectDataProvider ObjectInstance='_this.DataContext'                             MethodName='GetFromDate'                             x:Key='odp'>             <ObjectDataProvider.MethodParameters>                 <System:DateTime>2008-01-01</System:DateTime>               </ObjectDataProvider.MethodParameters>         </ObjectDataProvider>     </Window.Resources>     <Grid>         <Grid.RowDefinitions>             <RowDefinition Height='Auto'/>             <RowDefinition Height='*'/>         </Grid.RowDefinitions>          <dg:DatePicker Grid.Row='0' x:Name='dtpSource' >             <dg:DatePicker.SelectedDate>                 <Binding Source='{StaticResource odp}'                          Path='MethodParameters[0]'                                 BindsDirectlyToSource='True'                               Mode='OneWayToSource'/>             </dg:DatePicker.SelectedDate>         </dg:DatePicker>          <dg:DataGrid x:Name='dtgGrid'                           ItemsSource='{Binding Source={StaticResource odp}}'                           AutoGenerateColumns='True'                           Grid.Row='1'/>     </Grid> </Window> 

The code behind:

public partial class Window1 : Window {     public Window1()     {         InitializeComponent();          LoadData();     }      protected void LoadData()     {         DataContext = new Data();         ObjectDataProvider odp = this.Resources['odp'] as ObjectDataProvider;          odp.ObjectInstance = DataContext;     } } 

and the business object:

public class DataItem {     public string Name { get; set; }     public int BirthYear { get; set; } }  public class Data {     private readonly List<DataItem> data;      public Data()     {         data = new List<DataItem>();         data.Add(new DataItem { Name = 'John', BirthYear = 2007 });         data.Add(new DataItem { Name = 'Mike', BirthYear = 2007 });         data.Add(new DataItem { Name = 'Aaron', BirthYear = 2006 });         data.Add(new DataItem { Name = 'Bill', BirthYear = 2006 });         data.Add(new DataItem { Name = 'Steven', BirthYear = 2005 });         data.Add(new DataItem { Name = 'George', BirthYear = 2004 });         data.Add(new DataItem { Name = 'Britany', BirthYear = 2004 });     }      public List<DataItem> GetFromDate(DateTime dt)     {         return this.data.Where(d => d.BirthYear == dt.Year).ToList();     } }