I have a UserControl with a number of StackPanel's. I like to hide specific panels depending on the user action. A StackPanel which is visible on startup gives me a number of working buttons. The buttons have click events in the code behind file. After collapsing the panel and then making it visible again the buttons no longer work. Here is a part of my UserControl:
<StackPanel x:Name="buttonPanel" Orientation="Horizontal">
<Button x:Name="ReMindNodeNotes" Content=""
FontFamily="Segoe UI Symbol" FontSize="14" Foreground="#FF292323"
HorizontalAlignment="Left" BorderThickness="1" Padding="0"
UseLayoutRounding="True" Click="NoteClicked" />
<Button x:Name="ReMindNodeRemove" Content=""
FontFamily="Segoe UI Symbol" FontSize="14" Foreground="#FF292323"
HorizontalAlignment="Left" BorderThickness="1" Padding="0"
UseLayoutRounding="True" Click="RemoveClicked" />
</StackPanel>
And here is the code (for now just some text):
private void NoteClicked(object sender, RoutedEventArgs e)
{
System.Diagnostics.Debug.WriteLine("NoteClicked...");
}
private void RemoveClicked(object sender, RoutedEventArgs e)
{
System.Diagnostics.Debug.WriteLine("RemoveClicked...");
}
I have been looking for a solution the last two days. No luck so far. Who can help...?
THX Peter
Follow up 1...
Here is the code for collapsing the panel:
private void MoreClicked(object sender, RoutedEventArgs e)
{
System.Diagnostics.Debug.WriteLine(this.nodeName);
this.buttonPanel.Visibility =
this.buttonPanel.Visibility ==
Visibility.Visible ? Visibility.Collapsed : Visibility.Visible;
}
It works if the buttonPanel has focus. If the focus is on another panel it does not. Furthermore, what I probably should have mentioned... is that users can create multiple instances of the user control.
THX
Follow up 2...
I continue working on a solution of course... ;-) and I found a solution, which however is not the solution I want. Let me explain.
Users can interactively create multiple instances of the user control mentioned before. When a new instance is created, that instance gets focus. Now every instance has its own set of buttons which are on a stackpanel. When the focus goes to another instance I want the panel of the previous instance to collapse. The focus should then be set to the new (or selected existing) instance.
When I do this manually, it works! When I try to achieve this through the GotFocus and LostFocus events however, it does not. Here is the code for the manual solution (which works):
private void MoreClicked(object sender, RoutedEventArgs e)
{
this.buttonPanel.Visibility =
this.buttonPanel.Visibility ==
Visibility.Visible ? Visibility.Collapsed : Visibility.Visible;
}
Here are the LostFocus and GotFocus events:
private void NodeGotFocus(object sender, RoutedEventArgs e)
{
this.buttonPanel.Visibility = Visibility.Visible;
}
private void NodeLostFocus(object sender, RoutedEventArgs e)
{
this.buttonPanel.Visibility = Visibility.Collapsed;
}
I really appreciate your help! THX again...
Thanks for your sample morincer. The problem however is a little more complex. Let me try to explain the solution which I found after some more research. Maybe other developers can benefit from it as well.
I added the GotFocus and LostFocus events to my userconctrol. If I click somewhere inside the usercontrol the focus changes every time. Strange as these events are only defined on the usercontrol itself and not it's children. I have several buttons and a textbox inside the usercontrol and when I for example click on one of the buttons of the usercontrol that has focus the LostFocus and GotFocus events are fired for usercontrol anyway.
The most important event for me in this case is the LostFocus event. When the usercontrol looses focus - for example to another control - I want the button panel to disappear. Since the LostFocus event fires every time a object inside the usercontrol is touched, I cannot distinguish between the situation in which I want to hide and show the buttons.
I got a little closer to a solution by changing the LostFocus event as follows:
private void LostFocus(object sender, RoutedEventArgs e)
{
Object fo = FocusManager.GetFocusedElement();
if (fo.GetType().ToString().Contains("TextBox") ||
fo.GetType().ToString().Contains("ScrollViewer"))
{
this.buttonPanel.Visibility = Visibility.Collapsed;
}
}
This covers most of the situations. When the cursor is positioned in the TextBox the button panel is closed. The button panel is also closed when the user clicks on the background. This seems to be a ScrollViewer (found through debugging the code). Can anyone explain this...?
The situation which is not covered however, is when a user clicks on another usercontrol. It does of course when the user clicks on the TextBox (see the code) but not when the user clicks on a button. I tried to compare sender and FocusManager.GetFocusedElement(). Problem is that the sender returns the usercontrol (which is what I am looking for) but the FocusManager.GetFocusedElement() returns the button that was pressed. Now I could ask for it's parent which is a border then ask for the borders parent which is a stack panel and so on until I arrive at the usercontrol. A code behind file however was introduced with the idea to split design and logic while this solution would tie them together again. If I would change the XAML I would have to change the logic as well. Doesn't seem to be the right solution to me.
I found a solotion by giving every usercontrol a unique name in the constructor. I then give all the buttons unique names as well (I don't use them in my code anyway) starting with the name of the usercontrol. This then gives me the possibility to compare names at runtime and determine whether the focus has changed to another instance of the usercontrol. Here is the code:
private void NodeLostFocus(object sender, RoutedEventArgs e)
{
Object fo = FocusManager.GetFocusedElement();
if (fo.GetType().ToString().Contains("ScrollViewer"))
{
this.buttonPanel.Visibility = Visibility.Collapsed;
}
else if (fo.GetType().ToString().Contains("TextBox"))
{
if (!((TextBox)fo).Name.Contains(this.nodeName))
{
this.buttonPanel.Visibility = Visibility.Collapsed;
}
}
else if (fo.GetType().ToString().Contains("Button"))
{
if (!((Button)fo).Name.Contains(this.nodeName))
{
this.buttonPanel.Visibility = Visibility.Collapsed;
}
}
}
Now this works! But…I don't like the solution. I am depending on names instead of a good architecture. Does anyone hove an idea how to compare the actual sender with the usercontrol that is the parent of the button pressed (FocusManager.GetFocusedElement())? Or any other solution that relies on good programming?
THX again
I have an MVVM setup with a mainwindow that contains a ContentControl.
I set this to a particular viewmodel which then maps to a view.
A view is a usercontrol.
I want to be able to set the default keyboard focus to a default element in the usercontrol(View) when it loads so the application can eventually be driven just by using up, down, left, right and enter.
Some of my failed attempts are setting
FocusManager.FocusedElement="{Binding ElementName=DefaultElement}"
in my content control tag. This sets the logical focus but not the keyboard focus
I'd rather keep the solution in xaml if possable but have tried placing the following in code behind.
Keyboard.Focus(DefaultElement);
This does not work but if I popup a message box first it does. I'm a little confused as to why.
MessageBox.Show(Keyboard.FocusedElement.ToString());
Keyboard.Focus(DefaultElement);
EDIT::::
I just placed this in my onloaded event of my user control. It seems to work but can anyone see any issues that might arrise at this priority level. I.E a circumstance when the action will never run?
Dispatcher.BeginInvoke(
DispatcherPriority.ContextIdle,
new Action(delegate()
{
Keyboard.Focus(DefaultElement);
}));
It seems that this wpf the you have to implement a workaround on a case by case basis. The solution that seemed to work best, most of the time for me was to insert the focus code inside the dispatcher when OnVisible was changed. This sets the focus not only when the View/Usercontrol loads but also if you a changing Views by way of Visibility. If you Hide and then Show a ContentControl that is mapped to your ViewModels then the Loaded event won't fire and you'll be forced to Mouse input, or tabbing (Not so good if you want to navigate your app with a remote control).
VisibilityChanged will always fire however. This is what I ended up with for my listbox.
private void ItemsFlowListBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if ((bool)e.NewValue == true)
{
Dispatcher.BeginInvoke(
DispatcherPriority.ContextIdle,
new Action(delegate()
{
ItemsFlowListBox.Focus();
ItemsFlowListBox.ScrollIntoView(ItemsFlowListBox.SelectedItem);
}));
}
}
I had the same symptom for a WPF UserControl hosted in a Winforms application. Just wanted to note I was about to try this solution when I found a normal TabIndex in the Winforms app fixed it
Per How to set which control gets the focus on application start
"The one with the minimum tab index automatically gets the focus
(assuming the TabStop property is set to true). Just set the tab
indices appropriately."
It's a tricky one with no easy answer. I'm currently doing this, although I'm not sure I like it:
public MyView()
{
InitializeComponent();
// When DataContext changes hook the txtName.TextChanged event so we can give it initial focus
DataContextChanged +=
(sender, args) =>
{
txtName.TextChanged += OnTxtNameOnTextChanged;
};
}
private void OnTxtNameOnTextChanged(object o, TextChangedEventArgs eventArgs)
{
// Setting focus will select all text in the TextBox due to the global class handler on TextBox
txtName.Focus();
// Now unhook the event handler, since it's no longer required
txtName.TextChanged -= OnTxtNameOnTextChanged;
}
And in case you're wondering what the global class handler does, it's this:
protected override void OnStartup(StartupEventArgs e)
{
...
// Register a global handler for this app-domain to select all text in a textBox when
// the textBox receives keyboard focus.
EventManager.RegisterClassHandler(
typeof (TextBox), UIElement.GotKeyboardFocusEvent,
new RoutedEventHandler((sender, args) => ((TextBox) sender).SelectAll()));
which auto selects TextBox text when receiving keyboard focus.
Could you help me find the error in this one: The event triggers before even the windows form is loaded. I start to see the message Box and then I click OK,after that it loads the main screen.After that everything works perfectly, I wonder what triggers the ComboBox SelectionChanged Event before even loading the window.The FillComboBoxFamilyData(SegmentCode) just creates a dataset and puts the values int he ComboBox. Please Refer to this link for complete code.
Not able to make cascading comboboxes work
Any help would be highly appreciated.Thanks.
<ComboBox Height="23" HorizontalAlignment="Left" Margin="35,26,0,0" Name="comboBox1" VerticalAlignment="Top" Width="205" ItemsSource="{Binding Source={StaticResource tblSegmentViewSource}}" DisplayMemberPath="Segment Name" SelectedValuePath="Segment Code" SelectionChanged="comboBox1_SelectionChanged"/>
<ComboBox Margin="304,26,395,93" Name="comboBox2" />
private void comboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
MessageBox.Show(comboBox1.SelectedValue.ToString());
SegmentCode = Convert.ToInt32(comboBox1.SelectedValue.ToString());
FillComboBoxFamilyData(SegmentCode);
}
At the moment the data will be loaded (attached by the binding), SelectionChanged will be fired. Therefore, you have to check in your event-handler if your app is ready and all the data is loaded and attached. If not, return the event-handler without doing anything. This behaviour is by design.
ItemsSource="{Binding Source={StaticResource tblSegmentViewSource}}"
You can use the IsLoaded-property to detect, if the binding already has been evaluated. IsLoaded will not be true unless the databinding-engine has evaluated your xaml-bindings.
private void comboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e) {
if(!IsLoaded){
return;
}
.... your code here
You can use IsLoaded property of the combo box to test whether it is loaded yet. This is the cleanest and easiest solution which I could find:
var comboBox = (ComboBox)sender;
if (!comboBox.IsLoaded)
{
// This is when the combo box is not loaded yet and the event is called.
return;
}
I know this is an old question but I came across it twice trying to fix this in my project and had the same results as the OP. My list is populated after the IsLoaded is true. So, I figured I would post what I figured out for others. Just use the DropDowOpened event to set a bool to true. This way the SelectionChanged event won't fire until the user actually clicks on the dropdown.
private bool UserSeriesChange;
private void comboBox1_DropDownOpened(object sender, EventArgs e)
{
UserSeriesChange = true;
}
private void comboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if(!UserSeriesChange){
return;
}
.... your code here
I had this same problem and I found out that setting the starting-selection-index of the combox using xaml will trigger the selectionchanged event when program is loading which causes the error.
To solve you can either set the selection-index to -1 (the default) OR change the current-selection-index of the combobox using code after the program has loaded.
I have a Window that contains a custom UserControl. The UserControl needs to know when the Window containing it has been closed so that it can terminate a thread.
My best guess as to how to accomplish this is to handle the UserControl's Unloaded event. However, the Unloaded event only seems to be firing when the user actually clicks to close the window, but not when I programmatically call the Close() method on the window.
For reference sake, here are some of the relevant parts of my code.
MyWindow.xaml:
<Window x:Class="Namespace.MyWindow"
xmlns:controls="clr-namespace:Namespace.Controls">
<controls:MyControl/>
</Window>
MyControl.xaml:
<UserControl x:Class="Namespace.Controls.MyControl"
Unloaded="UserControl_Unloaded"/>
<!-- Stuff -->
</UserControl>
MyControl.xaml.cs:
void UserControl_Unloaded(object sender, RoutedEventArgs e)
{
// Stop the thread.
}
So just to recap, the UserControl_Unloaded() method above is getting called when I close the window "manually" (alt-F4, click the red "X", etc.), but not when from elsewhere in the code I call myWindow.Close(). Any ideas?
Turns out the answer in this question solves the problem for me, too. It still seems strange, though, that the Unloaded event isn't getting fired. Go figure.
In MyWindow class
this.Closing += new System.ComponentModel.CancelEventHandler(Window1_Closing);
void Window1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
call User Control Method()
}
Why just not connect handler to the window.Closed event? Your UserControl can walk through ui tree to find the window.
I have a UserControl which contains a TextBox. When my main window loads I want to set the focus to this textbox so I added Focusable="True" GotFocus="UC_GotFocus" to the UserControls definition and FocusManager.FocusedElement="{Binding ElementName=login}" to my main windows definition. In the UC_GotFocus method i simply call .Focus() on the control i want to focus on but this doesn't work.
All i need to do is have a TextBox in a UserControl receive focus when the application starts.
Any help would be appreciated, thanks.
I recently fixed this problem for a login splash screen that is being displayed via a storyboard when the main window is first loaded.
I believe there were two keys to the fix. One was to make the containing element a focus scope. The other was to handle the Storyboard Completed event for the storyboard that was triggered by the window being loaded.
This storyboard makes the username and password canvas visible and then fades into being 100% opaque. The key is that the username control was not visible until the storyboard ran and therefore that control could not get keyboard focus until it was visible. What threw me off for awhile was that it had "focus" (i.e. focus was true, but as it turns out this was only logical focus) and I did not know that WPF had the concept of both logical and keyboard focus until reading Kent Boogaart's answer and looking at Microsoft's WPF link text
Once I did that the solution for my particular problem was straightforward:
1) Make the containing element a focus scope
<Canvas FocusManager.IsFocusScope="True" Visibility="Collapsed">
<TextBox x:Name="m_uxUsername" AcceptsTab="False" AcceptsReturn="False">
</TextBox>
</Canvas>
2) Attach a Completed Event Handler to the Storyboard
<Storyboard x:Key="Splash Screen" Completed="UserNamePassword_Storyboard_Completed">
...
</Storyboard>
and
3) Set my username TextBox to have the keyboard focus in the storyboard completed event handler.
void UserNamePassword_Storyboard_Completed(object sender, EventArgs e)
{
m_uxUsername.Focus();
}
Note that calling item.Focus() results in the call Keyboard.Focus(this), so you don't need to call this explicitly. See this question about the difference between Keyboard.Focus(item) and item.Focus.
Its stupid but it works:
Pop a thread that waits a while then comes back and sets the focus you want. It even works within the context of an element host.
private void ListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
System.Threading.ThreadPool.QueueUserWorkItem(
(a) =>
{
System.Threading.Thread.Sleep(100);
someUiElementThatWantsFocus.Dispatcher.Invoke(
new Action(() =>
{
someUiElementThatWantsFocus.Focus();
}));
}
);
}
Just recently I had a list-box that housed some TextBlocks. I wanted to be able to double click on the text block and have it turn into a TextBox, then focus on it and select all the text so the user could just start typing the new name (Akin to Adobe Layers)
Anyway, I was doing this with an event and it just wasn't working. The magic bullet for me here was making sure that I set the event to handled. I figure it was setting focus, but as soon as the event went down the path it was switching the logical focus.
The moral of the story is, make sure you're marking the event as handled, that might be your issue.
“When setting initial focus at application startup, the element to
receive focus must be connected to a PresentationSource and the
element must have Focusable and IsVisible set to true. The recommended
place to set initial focus is in the Loaded event handler"
(MSDN)
Simply add a "Loaded" event handler in the constructor of your Window (or Control), and in that event handler call the Focus() method on the target control.
public MyWindow() {
InitializeComponent();
this.Loaded += new RoutedEventHandler(MyWindow_Loaded);
}
void MyWindow_Loaded(object sender, RoutedEventArgs e) {
textBox.Focus();
}
since i tried a fuzquat's solution and found it the most generic one, i thought i'd share a different version, since some complained about it looking messy. so here it is:
casted.Dispatcher.BeginInvoke(new Action<UIElement>(x =>
{
x.Focus();
}), DispatcherPriority.ApplicationIdle, casted);
no Thread.Sleep, no ThreadPool. Clean enough i hope.
UPDATE:
Since people seem to like pretty code:
public static class WpfExtensions
{
public static void BeginInvoke<T>(this T element, Action<T> action, DispatcherPriority priority = DispatcherPriority.ApplicationIdle) where T : UIElement
{
element.Dispatcher.BeginInvoke(priority, action);
}
}
now you can call it like this:
child.BeginInvoke(d => d.Focus());
WPF supports two different flavors of focus:
Keyboard focus
Logical focus
The FocusedElement property gets or sets logical focus within a focus scope. I suspect your TextBox does have logical focus, but its containing focus scope is not the active focus scope. Ergo, it does not have keyboard focus.
So the question is, do you have multiple focus scopes in your visual tree?
I found a good series of blog posts on WPF focus.
Part 1: It’s Basically Focus
Part 2: Changing WPF focus in code
Part 3: Shifting focus to the first available element in WPF
They are all good to read, but the 3rd part specifically deals with setting focus to a UI element in a UserControl.
Set your user control to Focusable="True" (XAML)
Handle the GotFocus event on your control and call yourTextBox.Focus()
Handle the Loaded event on your window and call yourControl.Focus()
I have a sample app running with this solution as I type. If this does not work for you, there must be something specific to your app or environment that causes the problem. In your original question, I think the binding is causing the problem.
I hope this helps.
After having a 'WPF Initial Focus Nightmare' and based on some answers on stack, the following proved for me to be the best solution.
First, add your App.xaml OnStartup() the followings:
EventManager.RegisterClassHandler(typeof(Window), Window.LoadedEvent,
new RoutedEventHandler(WindowLoaded));
Then add the 'WindowLoaded' event also in App.xaml :
void WindowLoaded(object sender, RoutedEventArgs e)
{
var window = e.Source as Window;
System.Threading.Thread.Sleep(100);
window.Dispatcher.Invoke(
new Action(() =>
{
window.MoveFocus(new TraversalRequest(FocusNavigationDirection.First));
}));
}
The threading issue must be use as WPF initial focus mostly fails due to some framework race conditions.
I found the following solution best as it is used globally for the whole app.
Hope it helps...
Oran
I converted fuzquat's answer to an extension method. I'm using this instead of Focus() where Focus() did not work.
using System;
using System.Threading;
using System.Windows;
namespace YourProject.Extensions
{
public static class UIElementExtension
{
public static void WaitAndFocus(this UIElement element, int ms = 100)
{
ThreadPool.QueueUserWorkItem(f =>
{
Thread.Sleep(ms);
element.Dispatcher.Invoke(new Action(() =>
{
element.Focus();
}));
});
}
}
}
I've noticed a focus issue specifically related to hosting WPF UserControls within ElementHosts which are contained within a Form that is set as an MDI child via the MdiParent property.
I'm not sure if this is the same issue others are experiencing but you dig into the details by following the link below.
Issue with setting focus within a WPF UserControl hosted within an ElementHost in a WindowsForms child MDI form
I don't like solutions with setting another tab scope for UserControl. In that case, you will have two different carets when navigating by keyboard: on the window and the another - inside user control. My solution is simply to redirect focus from user control to inner child control. Set user control focusable (because by default its false):
<UserControl ..... Focusable="True">
and override focus events handlers in code-behind:
protected override void OnGotFocus(RoutedEventArgs e)
{
base.OnGotFocus(e);
MyTextBox.Focus();
}
protected override void OnGotKeyboardFocus(KeyboardFocusChangedEventArgs e)
{
base.OnGotKeyboardFocus(e);
Keyboard.Focus(MyTextBox);
}
What did the trick for me was the FocusManager.FocusedElement attribute. I first tried to set it on the UserControl, but it didn't work.
So I tried putting it on the UserControl's first child instead:
<UserControl x:Class="WpfApplication3.UserControl1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Grid FocusManager.FocusedElement="{Binding ElementName=MyTextBox, Mode=OneWay}">
<TextBox x:Name="MyTextBox"/>
</Grid>
... and it worked! :)
I have user control - stack panel with two text boxes.The text boxes were added in contructor, not in the xaml. When i try to focus first text box, nothing happend.
The siggestion with Loaded event fix my problem. Just called control.Focus() in Loaded event and everthing.
Assuming you want to set focus for Username textbox, thus user can type in directly every time it shows up.
In Constructor of your control:
this.Loaded += (sender, e) => Keyboard.Focus(txtUsername);
After trying combinations of the suggestions above, I was able to reliably assign focus to a desired text box on a child UserControl with the following. Basically, give focus to the child control and have the child UserControl give focus to its TextBox. The TextBox's focus statement returned true by itself, however did not yield the desired result until the UserControl was given focus as well. I should also note that the UserControl was unable to request focus for itself and had to be given by the Window.
For brevity I left out registering the Loaded events on the Window and UserControl.
Window
private void OnWindowLoaded(object sender, RoutedEventArgs e)
{
ControlXYZ.Focus();
}
UserControl
private void OnControlLoaded(object sender, RoutedEventArgs e)
{
TextBoxXYZ.Focus();
}
I set it in the PageLoaded() or control loaded, but then I'm calling WCF async service and doing stuff that seems to lose the focus. I have to to set it at the end of all the stuff I do. That's fine and all, but sometimes I make changes to the code and then I forget that I'm also setting the cursor.
I had same problem with setting keyboard focus to canvas in WPF user control.
My solution
In XAML set element to Focusable="True"
In element_mousemove event create simple check:
if(!element.IsKeyBoardFocused)
element.Focus();
In my case it works fine.