The secret sauce behind {binding} in xaml
- 1. The Secret Sauce Behind {Binding} in XAML Brendon Page
- 2. {Overview} ⢠What is binding ⢠Why is it difficult ⢠Adding some Context ⢠Behind the scenes
- 3. {What Is It} DataUI textBox.Text = Value; Value = textBox.Text; <TextBox Text="{Binding}" /> ⢠Mechanism for interacting with data. ⢠Display, convert, update data
- 4. {Quick Demo}
- 5. {Difficult} ⢠Thereâs a lot of other things you need to know â DependencyObject /DependencyProperty â INotifyPropertyChanged / INotifyCollectionChanged â IValueConverter ⢠Cryptic debugging feedback ⢠Itâs abstract â MSDN (WPF) Overview ⢠More than 7500 words ⢠12 Images ⢠20 Code blocks
- 6. {A lot to know}
- 7. ⢠All errors are shown in the output window ⢠When data source is set â System.Windows.Data Error: 40 : BindingExpression path error: 'Name' property not found on 'object' ''Person' (HashCode=46763000)'. BindingExpression:Path=Name; DataItem='Person' (HashCode=46763000); target element is 'TextBox' (Name=''); target property is 'Text' (type 'String') ⢠When data source isnât set â {Debugging}
- 8. {Quick Demo}
- 9. {Context} <Window> <TextBox Text="{Binding Path=Name}" /> </Window > public sealed partial class MainWindow : Window { public MainPage() { DataContext = new Person { Name = "Brendon" }; } } XAML C# DataContext Binding Uses As itâs default datasource Cascadesdown
- 10. {Just an Object} <TextBox Text="{Binding Path=Name}" /> XAML TextBox textBox = new TextBox(); C# Binding binding = new Binding("Name"); textBox.SetBinding(TextBox.TextProperty, binding); textBox.Text = binding;
- 11. Design Time {But Wait Thereâs More} Runtime ⢠Does the work ⢠Read & writes data between source & target ⢠Subscribes to property changed events ⢠Maintains the relationship ⢠Describes the binding, Source, Target, DataItem, Path, Mode
- 12. {Conclusion} ⢠Interact with data ⢠Binding is tricky, until you understand it ⢠Context is important ⢠Itâs just an object