Example 6

This example illustrates data binding using a vector of .NET objects, in this case DateTime objects.

The XAML

The XAML shown below, describes a Window containing a StackPanel, inside which is a ListBox.

<Window 

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="NetObjects (DateTime) Example"
    SizeToContent="WidthAndHeight" >
    <StackPanel>
         <TextBlock Text="Dates of forthcoming Orthodox Easters"
          FontSize="18" Margin="5"/>
         <ListBox Name="EasterDates" Height="100"
          Margin="5" />
    </StackPanel>
</Window>

The APL Code

The function NetObjects is shown below.

     ∇ NetObjects;⎕USING;win;dt
[1]    ⎕USING←'System'
[2]    win←LoadXAML XAML
[3]    win.dates←win.FindName⊂'EasterDates'
[4]    dt←{⎕NEW DateTime ⍵}¨Easter
[5]    win.dates.ItemsSource←2015⌶'dt'
[6]    sink←win.ShowDialog
     ∇

NetObjects[3] uses FindName to obtain a ref to the ListBox (defined in the XAML) named EasterDates:

[3]    win.dates←win.FindName⊂'EasterDates'

The global variable Easter contains a vector of 3-element numeric vectors representing the dates of forthcoming Orthodox Easter Sundays.

      ↑Easter
2015 4 12
2016 5  1
2017 4 16
2018 4  8
2019 4 28
2020 4 19
2021 5  2
2022 4 24
2023 4 16
2024 5  5

NetObjects[4] creates a vector of DateTime objects from the global variable Easter.

[4]    dt←{⎕NEW DateTime ⍵}¨Easter

Then, NetObjects[5] creates a binding source object from this array and assigns it to the ItemsSource property of the ListBox.

[5]    win.dates.ItemsSource←2015⌶'dt'

Testing the Data Binding

      )LOAD wpfintro
      DataBinding.NETObjects.NETObjects

Figure 1: data binding netobjects1