Databases
StackOverflow2013
Postsdbo
PODependency property re-entrancy (or: why does this work?)
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PODependency property re-entrancy (or: why does this work?)
    primarykey
    data
    text
    <p>Put simply, I can create 2 dependency properties in a WPF control and put code in each property change notification to change the other property (i.e <code>PropA</code> change sets <code>PropB</code> and <code>PropB</code> change sets <code>PropA</code>).</p> <p>I would expect this to disappear up its own backside but WPF seems to handle it nicely. That's actually very handy for my purposes but I can't find this behaviour documented anywhere.</p> <p>So what's going on? Does the WPF dependency property change notification system guard against reentrancy?</p> <p>Representative code follows:</p> <p><strong>XAML</strong>:</p> <pre><code>&lt;Window x:Class="WPFReentrancy1.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="350" Width="525"&gt; &lt;Grid&gt; &lt;TextBox Text="{Binding PropB, UpdateSourceTrigger=PropertyChanged}"/&gt; &lt;/Grid&gt; &lt;/Window&gt; </code></pre> <p><strong>Code behind:</strong></p> <pre><code> public partial class MainWindow : Window { public string PropA { get { return (string)GetValue(PropAProperty); } set { SetValue(PropAProperty, value); } } public static readonly DependencyProperty PropAProperty = DependencyProperty.Register("PropA", typeof (string), typeof (MainWindow),new UIPropertyMetadata("0", PropAChanged)); public string PropB { get { return (string)GetValue(PropBProperty); } set { SetValue(PropBProperty, value); } } public static readonly DependencyProperty PropBProperty = DependencyProperty.Register("PropB", typeof (string), typeof (MainWindow), new UIPropertyMetadata("", PropBChanged)); private static void PropBChanged(DependencyObject lDependencyObject, DependencyPropertyChangedEventArgs lDependencyPropertyChangedEventArgs) { ((MainWindow) lDependencyObject).PropA = (string) lDependencyPropertyChangedEventArgs.NewValue; } private static void PropAChanged(DependencyObject lDependencyObject, DependencyPropertyChangedEventArgs lDependencyPropertyChangedEventArgs) { ((MainWindow) lDependencyObject).PropB = double.Parse((string) lDependencyPropertyChangedEventArgs.NewValue).ToString("0.000"); } public MainWindow() { InitializeComponent(); DataContext = this; PropA = "1.123"; } } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USH.B.
    1. USMarcE
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. PODependency property re-entrancy (or: why does this work?)
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PODependency property re-entrancy (or: why does this work?)
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PODependency property re-entrancy (or: why does this work?)
      1. USEamonn McEvoy
      1. VTFavorite
    1. COdon't have concrete answer, but suppose that: considering the WPF make recursive flow along the element's tree and associated properties too, it just "saves" (for concrete event) which nodes it has already passed and fired notification, so skip them if met them another time again.
      singulars
      1. PODependency property re-entrancy (or: why does this work?)
      1. USTigran
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload