I have some concept question here. I know how to select all text in TextBox or in PasswordBox. Via GotKeyboardFocus and PreviewMouseLeftButtonDown events, you know. This works fine.
XAML:
PreviewMouseLeftButtonDown="PasswordOnPreviewMouseDown"
GotKeyboardFocus="SelectAllPassword"
CodeBehind
private void SelectAllPassword(Object sender, RoutedEventArgs e)
{
var pb = (sender as PasswordBox);
if (pb != null)
pb.SelectAll();
}
private void PasswordOnPreviewMouseDown(Object sender, MouseButtonEventArgs e)
{
var pb = (sender as PasswordBox);
if (pb != null)
if (!pb.IsKeyboardFocusWithin)
{
e.Handled = true;
pb.Focus();
}
}
But question is - why this doesn't work?
XAML:
PreviewMouseLeftButtonDown="PasswordOnPreviewMouseDown"
CodeBehind:
private void PasswordOnPreviewMouseDown(Object sender, MouseButtonEventArgs e)
{
_txtPassword.SelectAll();
e.Handled = true;
}
Where _txtPassword - TextBox or PasswordBox control. So why I'm enforsed to Focus text control?
Actually, the selection is working.
You may feel that the text is not selected because it's not visually highlighted, but that's because the TextBox is not focused.
Try giving focus to your TextBox with the Tab key, you'll see the whole text highlighted.
Related
I have a C# WPF application with a User Control displayed inside a ScrollViewer:
<ScrollViewer HorizontalScrollBarVisibility="Auto" PreviewMouseWheel="ScrollViewer_PreviewMouseWheel" MouseWheel="ScrollViewer_MouseWheel">
<Drawing:DrawingWindow Name="Drawing" MouseWheel="Drawing_MouseWheel" PreviewMouseWheel="Drawing_PreviewMouseWheel"/>
</ScrollViewer>
I've tried putting an event-handler for all scroll-related events both on the contained element and the ScrollViewer itself. Each of the handlers is basically just this:
private void Drawing_MouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
}
private void ScrollViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
}
private void Drawing_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
}
private void ScrollViewer_MouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
}
Even with all this, the vertical scroll-bar still responds to the mouse-wheel when I scroll on top of the Drawing element.
What am I doing wrong? I've seen a lot of posts where setting e.handled appears to be the solution:
Disable mouse wheel scrolling in scrollviewer
I would like to set the focus of a WPF TextBox from codebehind (not the TextBox's codebehind, but some parent control) and select all text in the TextBox from the TextBoxs codebehind when it receives that focus.
I focus the TextBox like this:
var scope = FocusManager.GetFocusScope(txt);
FocusManager.SetFocusedElement(scope, txt);
and listen to the event in the TextBox like this in the TextBoxs codebehind:
AddHandler(GotFocusEvent, new RoutedEventHandler(SelectAllText), true);
and try to select the text like this:
private static void SelectAllText(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
textBox.SelectAll();
}
But the text doesn't get selected. How can I modify this to work as I'd like it to?
You will have to set Keyboard focus on the TextBox before selecting the text
Example:
private static void SelectAllText(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
{
Keyboard.Focus(textBox);
textBox.SelectAll();
}
}
How I can show or hide a groupbox from xaml.cs. I try to do this in the checkbox's event:
private void cbDaily_Checked(object sender, RoutedEventArgs e)
{
gbCalendar.Visibility = Visibility.Visible;
}
But this don't work.
It must be work on checked/unchecked events of checkbox like this way :
private void chkTest_Checked(object sender, RoutedEventArgs e)
{
grpTest.Visibility = System.Windows.Visibility.Visible;
}
private void chkTest_Unchecked(object sender, RoutedEventArgs e)
{
grpTest.Visibility = System.Windows.Visibility.Hidden;
}
It is working fine in my sample application. Can you please give more details of your problem, so I can have better idea. Is event fired properly ? Make sure name of groupbox in code behind is correct or not ?
Working on a TouchScreen application which also has a keyboard attached, I have the following problem:
The WPF window has a TextBox, which should receive ALL keyboard input. There are also Buttons and a ListBox, which are solely used by the TouchScreen(=Mouse).
A very simple example looks like this:
<Window x:Class="KeyboardFocusTest.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1">
<StackPanel>
<TextBox Text="{Binding Input, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
PreviewLostKeyboardFocus="TextBox_PreviewLostKeyboardFocus"/>
<Button Click="Button_Click">Add</Button>
<ListBox ItemsSource="{Binding Strings}" />
</StackPanel>
</Window>
To keep the TextBox always focused, I just do:
private void TextBox_PreviewLostKeyboardFocus(object sender, System.Windows.Input.KeyboardFocusChangedEventArgs e)
{
e.Handled = true;
}
So far so good - the problem now is, that I can't select items from the ListBox anymore. This only seems to work, if the ListBox has the keyboard focus. But if I loose the keyboard focus on the TextBox, I can't enter text anymore without clicking it first.
Any ideas, comments suggestions are welcome!
There might be a more elegant solution for this, but you could always handle the PreviewKeyDown event at the Window level, and pass focus to the TextBox if it doesn't already have it, instead of preventing it from losing focus in the first place. That way, the ListBox can use focus as is normal, but as soon as a key is pressed focus jumps right to the TextBox. In addition, you can filter out keys that you don't want to switch focus - the arrow keys come to mind, which could then be used to move up and down in the ListBox.
Adding an event handler like the following should do the trick:
private void Window_PreviewKeyDown(object sender, KeyEventArgs e)
{
if (!textBox.IsFocused)
{
textBox.Focus();
}
}
Based on Nicholas' suggestion (thx!), here's a markup extension, which is used like:
<TextBox Helpers:KeyboardFocusAttractor.IsAttracted="true" />
It seems to work, and ANTS didn't show any memory leaks. But when it comes to WPF and especially events and bindings, you never know, so use with care!
public static class KeyboardFocusAttractor
{
public static readonly DependencyProperty IsAttracted = DependencyProperty.RegisterAttached("IsAttracted",
typeof (bool), typeof (KeyboardFocusAttractor), new PropertyMetadata(false, OnIsAttracted));
private static void OnIsAttracted(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var isAttracted = (bool) e.NewValue;
var controlWithInputFocus = d as Control;
if (controlWithInputFocus != null)
{
if (isAttracted)
{
new KeyboardInputFocusEventManager(controlWithInputFocus);
}
}
}
public static void SetIsAttracted(DependencyObject dp, bool value)
{
dp.SetValue(IsAttracted, value);
}
public static bool GetIsAttracted(DependencyObject dp)
{
return (bool) dp.GetValue(IsAttracted);
}
private class KeyboardInputFocusEventManager
{
private readonly Control _control;
private Window _window;
public KeyboardInputFocusEventManager(Control control)
{
_control = control;
_control.Loaded += ControlLoaded;
_control.IsVisibleChanged += ControlIsVisibleChanged;
_control.Unloaded += ControlUnloaded;
}
private void ControlLoaded(object sender, RoutedEventArgs e)
{
_window = Window.GetWindow(_control);
if (_window != null)
{
_control.Unloaded += ControlUnloaded;
_control.IsVisibleChanged += ControlIsVisibleChanged;
if (_control.IsVisible)
{
_window.PreviewKeyDown += ParentWindowPreviewKeyDown;
}
}
}
private void ControlUnloaded(object sender, RoutedEventArgs e)
{
_control.Unloaded -= ControlUnloaded;
_control.IsVisibleChanged -= ControlIsVisibleChanged;
}
private void ControlIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (_window != null)
{
_window.PreviewKeyDown -= ParentWindowPreviewKeyDown;
}
if (_control.IsVisible)
{
_window = Window.GetWindow(_control);
if (_window != null)
{
_window.PreviewKeyDown += ParentWindowPreviewKeyDown;
}
}
}
private void ParentWindowPreviewKeyDown(object sender, KeyEventArgs e)
{
Keyboard.Focus(_control);
}
}
}
How can focus the controls when select a tabitem in a tabcontrol?
You should capture the Selection changed event of the TabControl and inside that you focus the control you need. Just as
private void TabControl1_SelectionChanged(object sender, EventArgs e)
{
control1.Focus();
}
Not sure I understand what you're asking completely, but you probably want to capture the SelectionChanged event for the TabControl:
public Window1()
{
InitializeComponent();
TabControl1.SelectionChanged += TabControl1_SelectionChanged;
}
private void TabControl1_SelectionChanged(object sender, EventArgs e)
{
TabItem item = (TabItem)TabControl1.SelectedItem;
// Find the first control in the TabItem content and focus it?
}