Set the focus on a textbox in xaml wpf

You can use the FocusManager.FocusedElement attached property for this purpose. Here’s a piece of code that set the focus to TxtB by default. <StackPanel Orientation=”Vertical” FocusManager.FocusedElement=”{Binding ElementName=TxtB}”> <TextBox x:Name=”TxtA” Text=”A” /> <TextBox x:Name=”TxtB” Text=”B” /> </StackPanel> You can also use TxtB.Focus() in your code-behind if you don’t want to do this in XAML.

Interactively validating Entry widget content in tkinter

The correct answer is, use the validatecommand attribute of the widget. Unfortunately this feature is severely under-documented in the Tkinter world, though it is quite sufficiently documented in the Tk world. Even though it’s not documented well, it has everything you need to do validation without resorting to bindings or tracing variables, or modifying the … Read more

Bug With Firefox – Disabled Attribute of Input Not Resetting When Refreshing

This is a “feature” of Firefox which remembers form input values across page refreshes. To fix this behavior, you simply set autocomplete=”off” on the form containing the inputs, or just directly to the input. This stops autocomplete from working and prevents the browser from remembering the state of input fields. Alternatively, you can just “hard-refresh” … Read more

Bind TextBox on Enter-key press

You can make yourself a pure XAML approach by creating an attached behaviour. Something like this: public static class InputBindingsManager { public static readonly DependencyProperty UpdatePropertySourceWhenEnterPressedProperty = DependencyProperty.RegisterAttached( “UpdatePropertySourceWhenEnterPressed”, typeof(DependencyProperty), typeof(InputBindingsManager), new PropertyMetadata(null, OnUpdatePropertySourceWhenEnterPressedPropertyChanged)); static InputBindingsManager() { } public static void SetUpdatePropertySourceWhenEnterPressed(DependencyObject dp, DependencyProperty value) { dp.SetValue(UpdatePropertySourceWhenEnterPressedProperty, value); } public static DependencyProperty GetUpdatePropertySourceWhenEnterPressed(DependencyObject dp) { … Read more