Is there Selected Tab Changed Event in the standard WPF Tab Control

Question

In WPF, is there an event that can be used to determine when a TabControl's selected tab changes?

I have tried using TabControl.SelectionChanged but it is getting fired many times when a child's selection within a tab is changed.

score 143 · Accepted Answer · edited Mar 27 '23 at 22:19

143

You need to check the event's source to isolate the outer-most TabControl you are looking for.

I tied this in the handler to make it work:

void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    if (e.Source is TabControl)
    {
        // do work when tab is changed
    }
}

edited Mar 27 '23 at 22:19

Aurumaker72

33
1
7

answered Apr 21 '09 at 14:49

Jon Kragh

4,529
5
26
26

3

I thought this wasn't working but then I realized I was checking for `sender` instead of `e.Source` – Guillermo Ruffino Apr 30 '13 at 19:46
5

or just add `e.Handled = true` to prevent it from bubbling up – Brock Hensley Sep 04 '13 at 12:43
@BrockHensley: That could cause you to have to add a whole lot of event handlers that wouldn't otherwise be necessary. – Ben Voigt Jul 28 '21 at 17:05

score 93 · Answer 2 · edited Dec 24 '12 at 17:56

If you set the x:Name property to each TabItem as:

<TabControl x:Name="MyTab" SelectionChanged="TabControl_SelectionChanged">
    <TabItem x:Name="MyTabItem1" Header="One"/>
    <TabItem x:Name="MyTabItem2" Header="2"/>
    <TabItem x:Name="MyTabItem3" Header="Three"/>
</TabControl>

Then you can access to each TabItem at the event:

private void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    if (MyTabItem1.IsSelected)
    // do your stuff
    if (MyTabItem2.IsSelected)
    // do your stuff
    if (MyTabItem3.IsSelected)
    // do your stuff
}

score 61 · Answer 3 · answered Feb 27 '14 at 08:02

61

If you just want to have an event when a tab is selected, this is the correct way:

<TabControl>
    <TabItem Selector.Selected="OnTabSelected" />
    <TabItem Selector.Selected="OnTabSelected" />
    <TabItem Selector.Selected="OnTabSelected" />
    <!-- You can also catch the unselected event -->
    <TabItem Selector.Unselected="OnTabUnSelected" />
</TabControl>

And in your code

    private void OnTabSelected(object sender, RoutedEventArgs e)
    {
        var tab = sender as TabItem;
        if (tab != null)
        {
            // this tab is selected!
        }
    }

answered Feb 27 '14 at 08:02

MicBig

721
5
2

Unfortunately as nice as this one looks, I don't get the Selected property available to me in xaml, just the IsSelected. Sorry. – PHenry Mar 28 '14 at 21:05
2

I stand corrected....kind of. DOH! When I try to type about the above in VS, it gives me the red squigglies, hence I thought it was wrong. BUT when I cut'n'pasted it in and just blindly F5'd it, to my astonishment, IT WORKED. HUH?! Why did it work THAT way? – PHenry Mar 28 '14 at 21:13
2

How can I access "Selector.Selected" event in code instead of xaml – Ahmed_Faraz Feb 14 '20 at 07:08
2

@Ahmed_Faraz: `someTabItem.AddHandler(Selector.SelectedEvent, ....` – Ben Voigt Jul 28 '21 at 17:03

score 15 · Answer 4 · answered Apr 21 '09 at 14:39

15

You could still use that event. Just check that the sender argument is the control you actually care about and if so, run the event code.

answered Apr 21 '09 at 14:39

Nidonocu

12,476
7
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score 8 · Answer 5 · answered Sep 06 '17 at 11:36

If you're using the MVVM pattern then it is inconvenient (and breaks the pattern) to use the event handler. Instead, you can bind each individual TabItem's Selector.IsSelected property to a dependency property in your viewmodel and then handle the PropertyChanged event handler. That way you know exactly which tab was selected/deselected based on the PropertyName and you have a special handler for each tab.

Example: MainView.xaml

<TabControl>
 <TabItem Header="My tab 1" Selector.IsSelected="{Binding IsMyTab1Selected}"> ... </TabItem>
 <TabItem Header="My tab 2" Selector.IsSelected="{Binding IsMyTab2Selected}"> ... </TabItem>
</TabControl>

Example: MainViewModel.cs

public bool IsMyTab1Selected {
 get { return (bool)GetValue(IsMyTab1SelectedProperty); }
 set { SetValue(IsMyTab1SelectedProperty, value); }
}
public static readonly DependencyProperty IsMyTab1SelectedProperty =
DependencyProperty.Register("IsMyTab1Selected", typeof(bool), typeof(MainViewModel), new PropertyMetadata(true, new PropertyChangedCallback(MyPropertyChanged)));

public bool IsMyTab2Selected {
 get { return (bool)GetValue(IsMyTab2SelectedProperty); }
 set { SetValue(IsMyTab2SelectedProperty, value); }
}
public static readonly DependencyProperty IsMyTab2SelectedProperty =
DependencyProperty.Register("IsMyTab2Selected", typeof(bool), typeof(MainViewModel), new PropertyMetadata(false, new PropertyChangedCallback(MyPropertyChanged)));

private void MyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
 if (e.Property.Name == "IsMyTab1Selected") {
  // stuff to do
 } else if (e.Property.Name == "IsMyTab2Selected") {
  // stuff to do
 }
}

If your MainViewModel is INotifyPropertyChanged rather than DependencyObject, then use this instead:

Example: MainViewModel.cs

public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName) {
 PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}

public MainViewModel() {
 PropertyChanged += handlePropertyChanged;
}

public bool IsMyTab1Selected {
 get { return _IsMyTab1Selected ; }
 set {
  if (value != _IsMyTab1Selected ) {
   _IsMyTab1Selected = value;
   OnPropertyChanged("IsMyTab1Selected ");
  }
 }
}
private bool _IsMyTab1Selected = false;

public bool IsMyTab2Selected {
 get { return _IsMyTab2Selected ; }
 set {
  if (value != _IsMyTab2Selected ) {
   _IsMyTab2Selected = value;
   OnPropertyChanged("IsMyTab2Selected ");
  }
 }
}
private bool _IsMyTab2Selected = false;

private void handlePropertyChanged(object sender, PropertyChangedEventArgs e) {
 if (e.PropertyName == "IsMyTab1Selected") {
  // stuff to do
 } else if (e.PropertyName == "IsMyTab2Selected") {
  // stuff to do
 }
}

score 4 · Answer 6 · answered Dec 12 '09 at 14:39

The event generated is bubbling up until it is handled.

This xaml portion below triggers ui_Tab_Changed after ui_A_Changed when the item selected in the ListView changes, regardless of TabItem change in the TabControl.

<TabControl SelectionChanged="ui_Tab_Changed">
  <TabItem>
    <ListView SelectionChanged="ui_A_Changed" />
  </TabItem>
  <TabItem>
    <ListView SelectionChanged="ui_B_Changed" />
  </TabItem>
</TabControl>

We need to consume the event in ui_A_Changed (and ui_B_Changed, and so on):

private void ui_A_Changed(object sender, SelectionChangedEventArgs e) {
  // do what you need to do
  ...
  // then consume the event
  e.Handled = true;
}

score 4 · Answer 7 · answered Apr 21 '09 at 14:45

That is the correct event. Maybe it's not wired up correctly?

<TabControl SelectionChanged="TabControl_SelectionChanged">
    <TabItem Header="One"/>
    <TabItem Header="2"/>
    <TabItem Header="Three"/>
</TabControl>

in the codebehind....

private void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    int i = 34;
}

if I set a breakpoint on the i = 34 line, it ONLY breaks when i change tabs, even when the tabs have child elements and one of them is selected.

put a grid in the tab, selecting a grid row will bubble up to the tab selected event if not handled before it gets there. — Paul Swetz, Mar 23 '18 at 14:10

score 2 · Answer 8 · answered Dec 05 '11 at 14:15

This code seems to work:

    private void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        TabItem selectedTab = e.AddedItems[0] as TabItem;  // Gets selected tab

        if (selectedTab.Name == "Tab1")
        {
            // Do work Tab1
        }
        else if (selectedTab.Name == "Tab2")
        {
            // Do work Tab2
        }
    }

score 0 · Answer 9 · answered Apr 12 '23 at 17:38

If you're doing mvvm, you can also do this by binding to the SelectedIndex Property of TabControl:

<TabControl SelectedIndex="{Binding SelectedTabIndex}"

Then you get notified of the change when the Property updates, and you immediately get the index of the selected TabItem.

score -2 · Answer 10 · answered May 09 '14 at 07:08

If anyone use WPF Modern UI,they cant use OnTabSelected event.but they can use SelectedSourceChanged event.

like this

<mui:ModernTab Layout="Tab" SelectedSourceChanged="ModernTab_SelectedSourceChanged" Background="Blue" AllowDrop="True" Name="tabcontroller" >

C# code is

private void ModernTab_SelectedSourceChanged(object sender, SourceEventArgs e)
    {
          var links = ((ModernTab)sender).Links;

          var link = this.tabcontroller.Links.FirstOrDefault(l => l.Source == e.Source);

          if (link != null) {
              var index = this.tabcontroller.Links.IndexOf(link);
              MessageBox.Show(index.ToString());
          }            
    }

Using third party arguments are never a solution and should be highly discouraged. — Steven Borges, Aug 25 '16 at 11:42
@steven I wrote this for WPF MUI and this is not answer to question too.but this could be answer wpf mui user.That is why I put this as a answer. thank you — Sandun Harshana, Dec 30 '16 at 03:53

Is there Selected Tab Changed Event in the standard WPF Tab Control

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