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WPF changing several properties one after another

I have a TabControl that contains a TextBox per tab. I need to select a tab programmatically and then set the selection of the TextBox and set the focus to the TextBox.
My problem is, when I first select a new tab in code and then set the focus to the textbox it doesn't work.
When the desired tab is already the selected tab and I set the focus to the textbox inside the tab, it's working.
It seems, that performing several actions on WPF elements does not work.
What is the right way to first switch the tab of a tabcontrol and then set the focus to a child in the newly selected TabItem?
Edit: I've found something on the Internet: Waiting for the render thread to complete:
https://social.msdn.microsoft.com/Forums/vstudio/en-US/693fbedb-efa6-413e-ab66-530c6961d3fb/how-to-wait-for-the-wpf-render-thread-to-catch-up?forum=wpf
Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, new Action(() => { })).Wait();
But is this the right way?
BTW: What is the difference between:
Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, new Action(() => { })).Wait();
Dispatcher.Invoke(DispatcherPriority.ApplicationIdle, new Action(() => { }));

Use the FocusManager.SetFocusedElement() method.
Focus has some nuances, you can learn more here.
XAML
<TabControl>
<TabItem Header="One"
x:Name="tabOne">
<Button HorizontalAlignment="Center"
VerticalAlignment="Center"
Content="Set Focus"
Click="Button_Click" />
</TabItem>
<TabItem Header="Two"
Name="tabTwo">
<StackPanel>
<TextBox Name="txtOne" />
<TextBox Name="txtTwo" />
</StackPanel>
</TabItem>
<TabItem Header="Three"
x:Name="tabThree">
<StackPanel>
<TextBox Name="txtThree" />
<TextBox Name="txtFour" />
</StackPanel>
</TabItem>
</TabControl>
CODE
private void Button_Click(object sender, RoutedEventArgs e)
{
tabTwo.IsSelected = true;
FocusManager.SetFocusedElement(tabTwo, txtTwo);
}

WPF popup wont close even with StaysOpen="false"

I am trying to achieve the following:
User brings up a context menu in a datagrid.
User selects a context menu item which then opens a popup and displays some information.
when the user clicks anywhere else in the application, not in the popup, the popup closes.
Everything works fine until I come to closing the popup.
From searching elsewhere I am aware that I need Staysopen to be set to false ( which it is)
I also read the best way is to bind the IsOpen value to a property in the view model and set its binding to 2 way ( also done )
As a side note I have found that if I add a textbox and click inside the box, when I then click outside the popup it closes as desired.
Another thing I unsuccessfully tried as a workaround was to programmatically set the keyboard focus on the text box to get the "autoclose" functionality I desired.
Here is code:
xaml -
<Popup Name="PredictionsPopup" Height="200" Width="200" AllowsTransparency="false" StaysOpen="False" IsOpen="{Binding DisplaySummaryPopup, Mode=TwoWay}">
<StackPanel Background="{DynamicResource {x:Static SystemColors.ControlBrushKey}}">
<TextBlock Text="here is some stuff" />
<TextBox Name="hiddenBox" Text="moo"/>
</StackPanel>
</Popup>
Codebehind that sets the property on the viewmodel when the menu item is selected.
private void CurrentPredicitions_OnClick(object sender, RadRoutedEventArgs e)
{
PredictionsPopup.Placement = PlacementMode.MousePoint;
ViewModel.DisplaySummaryPopup = true;
}
Viewmodel property
public bool? DisplaySummaryPopup
{
get
{
return this.displaySummaryPopup;
}
set
{
this.displaySummaryPopup = value;
RaisePropertyChanged(() => this.DisplaySummaryPopup);
}
}
Please let me know if you need anymore details.

Here you have a working example:
MainWindow XAML:
<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Popup Name="PredictionsPopup" Height="200" Width="200" AllowsTransparency="false" StaysOpen="False" IsOpen="{Binding DisplaySummaryPopup, Mode=TwoWay}">
<StackPanel Background="Red">
<TextBlock Text="here is some stuff" />
<TextBox Name="hiddenBox" Text="moo"/>
</StackPanel>
</Popup>
<DataGrid AutoGenerateColumns="False" Name="dataGrid1" IsReadOnly="True" >
<DataGrid.Columns>
<DataGridTextColumn Header="Site" Width="150" />
<DataGridTextColumn Header="Subject" Width="310" />
</DataGrid.Columns>
<DataGrid.ContextMenu>
<ContextMenu>
<MenuItem Header="Click Me" Click="ButtonBase_OnClick">
</MenuItem>
</ContextMenu>
</DataGrid.ContextMenu>
</DataGrid>
</Grid>
</Window>
MainWindow cs :
public MainWindow()
{
InitializeComponent();
DataContext = new TestViewModel();
}
private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
{
PredictionsPopup.Placement = PlacementMode.MousePoint;
PredictionsPopup.IsOpen = true;
}
ViewModel:
public class TestViewModel : INotifyPropertyChanged
{
private bool _displaySumarry;
public bool DisplaySummaryPopup
{
get { return _displaySumarry; }
set
{
_displaySumarry = value;
OnPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}
I think that your implementation for INotifyPropertyChanged is the one which causes the problem. I tried myself the code and is working now.

After trying to track this problem down I worked out that the issue is something to do with the context menu. I know this because as per the answer above instead of launching my popup via a context menu I launched it from a test button and all worked as expected.
I still don't know the exact reason for this issue but I think its something to do with the fact that the context menu is itself a subclass of popup and the focus isn't being set correctly on the new popup, so it never detects popup loss and closes.
To get round my problem I have added a close button to the popup, and then whenever the active tab in the control that hosts the popup changes it fires an event that the popup picks up and closes.

Had the same problem. The reason was, that the toggle button's ClickMode property was set to "Press". Setting it back to "Release" solved it :).

For me, the solution was to add this line in the constructor of the popup's code-behind:
LostFocus += delegate { this.IsOpen = false; };
Many hours were spent, when such a quickie line was all it took :)

I faced same problem a few times. Every time it was occuring, when a popup was changing its "isOpen" property to true from an event, which was raised from listview or datagrid element, like selectedItemChanged event, or items mouseUp event. I don't know reason, however resolved it by opening the popup from another task with code as below:
Task.Run(()=> Dispatcher.Invoke( () => myPopup.IsOpen = true));
Dispatcher is used to avoid an exception from changing any GUI object property from another than the main thread.

How to prevent a UserControl from taking focus away from its parent?

I am using MVVM for my application and have a form that allows the user to enter basic personnel information. The form includes a UserControl which is, basically, an ItemsControl that includes textBoxes that can be dynamically created. This is a simplified version:
<ItemsControl x:Name="items" ItemsSource="{Binding MyItemsCollection}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid x:Name="row">
<TextBox x:Name="textBox" Text="{Binding ContactInfo, ValidatesOnExceptions=True}" extensions:FocusExtension.IsFocused="{Binding IsFocused}"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<Button x:Name="NewItemButton" Command="{Binding AddItemToMyCollectionCommand}" />
I want the TextBox that has just been created to receive focus, therefore I added an attached property. This is part of it:
public static readonly DependencyProperty IsFocusedProperty =
DependencyProperty.RegisterAttached("IsFocused", typeof(bool), typeof(FocusExtension), new UIPropertyMetadata(false, OnIsFocusedPropertyChanged));
private static void OnIsFocusedPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var uie = (UIElement)d;
if ((bool)e.NewValue)
{
uie.Focus();
}
}
In the form that contains the UserControl there are several other text boxes before and after. The UserControl has its own ViewModel, which I set as the DataContext of the control through a property in the container's ViewModel. Basically, a simplified version of the container looks like this:
<StackPanel Orientation="Horizontal" />
<TextBox x:Name="firstName" />
<TextBox x:Name="lastName" />
<local:DynamicFormUserControl
x:Name="phones"
DataContext="{Binding PhonesViewModel}" />
<local:DynamicFormUserControl
x:Name="emails"
DataContext="{Binding EmailsViewModel}" />
<TextBox x:Name="address" />
</StackPanel>
My problem is that I want the firstName TextBox to get the focus when the form is loaded for the first time, but the form keeps on placing the focus on the first TextBox of the phones UserControl. I tried to override it by using firstName.Focus() on the Loaded event of the form, but this didn't work, and no matter what I tried the focus is still on the phones userControl instead of the first element in the form that contains it.
Does anybody have any idea how to solve this?
Thanks.

Here you go
add FocusManager.FocusedElement="{Binding ElementName=firstName}" to your stack panel
<StackPanel Orientation="Horizontal"
FocusManager.FocusedElement="{Binding ElementName=firstName}"/>
<TextBox x:Name="firstName" />
<TextBox x:Name="lastName" />
<local:DynamicFormUserControl
x:Name="phones"
DataContext="{Binding PhonesViewModel}" />
<local:DynamicFormUserControl
x:Name="emails"
DataContext="{Binding EmailsViewModel}" />
<TextBox x:Name="address" />
</StackPanel>
also notice that you may need to prevent items control in the user control from focusing itself
<ItemsControl x:Name="items" Focusable="False" >
<ItemsControl.ItemTemplate>

I guess I managed to find a solution. The problem was that the form I created was itself a user control inside a window, and never got focus. I didn't think that would be relevant so I didn't mention it in my previous post- sorry. I found in this solution for forcing focus to a user control.
Basically, when I have a UserControl inside a window it doesn't get focus even if I try to set the focus with either Focus() or FocusedElement. So to overcome this problem I found on a different post a workaround. Basically I added it to the code-behind of the UserControl that contains the firstName TextBox. If we call the UserControl, say, PersonalInfoUserControl, the constructor of the control would look like this:
public PersonalInfoUserControl()
{
InitializeComponent();
this.IsVisibleChanged += new DependencyPropertyChangedEventHandler(UserControl_IsVisibleChanged);
}
I added an event handler to the IsVisibleChanged event of the control. The method would look like this:
void UserControl_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if ((bool)e.NewValue == true)
{
Dispatcher.BeginInvoke(
DispatcherPriority.ContextIdle,
new Action(delegate()
{
firstName.Focus();
}));
}
}

Is this concept of a button containing a textbox possible?

Recently I had been looking for a way to make the tabs in a TabControl editable and came across This example on telerik's website. That did exactly what I wanted but it got me thinking about a similar usage for buttons. I was wondering if it would be possible to use something like that and make a button that would show a textbox instead of the content presenter when say, you right click the button? I tried to make something like this work but so far have only ended up with a blank button.
<Button x:Name="SB" Height="222" Width="222" Click="SB_Click">
<ContentControl.ContentTemplate>
<DataTemplate>
<local:SuperButton Content="{Binding Path=x, Mode=TwoWay}"/>
</DataTemplate>
</ContentControl.ContentTemplate>
</Button>
Where x is a string variable and using the code behind from the link above (with a class name change, of course).
edit: This button will be in an itemscontrol, so I don't think naming the inner elements in xaml will work, but I do like the ease of Wolfgang's answer.

The WPF Content Model is really flexible and allows literally anything inside anything.
This is perfectly valid XAML:
<Button>
<TextBox/>
</Button>
Or even:
<Button>
<MediaElement Source="C:\Videos\WildLife.wmv"/>
</Button>

You can simply host a (e.g.) label (TextBlock) with the text AND a TextBox inside the Button and set their Visiblity properties.
That way, if you right click the button, the TextBox shows up.
<Button>
<Grid>
<TextBox Text=normal button caption" x:Name="label" />
<TextBox
x:Name="textbox"
Text="visible on right click"
MouseRightButtonDown="HandleRightClick"/>
</Grid>
</Button>
And then in your C# code create an event handler to set the Visiblity correctly.
void HandleRightClick(object sender, MouseButtonEventArgs e)
{
label.Visibility = Visibility.Collapsed;
textBlock.Visibility = Visibility.Visible;
}

Open Window Activate not working with button inside menu

I have a really strange behaviour, and I hope someone can help me out.
I have the following XAML layout:
<StackPanel Orientation="Horizontal">
<Menu>
<Menu.Items>
<MenuItem Padding="2,0,2,0">
<MenuItem.Header>
<Button Content="Details"
Click="Details_Click" />
</MenuItem.Header>
</MenuItem>
</Menu.Items>
</Menu>
<Button Content="Details"
Click="Details_Click" />
</StackPanel>
Please notice that both buttons have the same Event registered.
The Details_Click Event looks like this:
private void Details_Click(object sender, RoutedEventArgs e)
{
var viewer = new DictionaryViewer();
viewer.ShowActivated = true;
viewer.Show();
viewer.Topmost = true;
viewer.Topmost = false;
viewer.Activate();
viewer.Focus();
e.Handled = true;
return;
}
Now I am facing the problem, even with all the code from above the Window doesnt show up activated when I press the button inside the Menu but outside of it works with just .Activate();.
(How I know that window isnt activated: need 2 clicks to close/minimize/maximize it)
Why would my XAML Layout ruin the Activation of the DictionaryViewer(); window, with the button inside Menu?
(To your information the DictionaryViewer is totally empty, its a fresh window nothing implemented yet)
Edit:
Yes, I know there is the MenuItem_Click Event that may make it work, but I need/want the button inside the Menu how can I fix this issue?

THe reason this is happening is because the Button inside the MenuItem is gaining Focus after the Window has opened.
If you set the Focusable property of the button inside MenuItem, this fixes the issue.
E.g.
<StackPanel Orientation="Horizontal">
<Menu>
<Menu.Items>
<MenuItem Padding="2,0,2,0">
<MenuItem.Header>
<Button Content="Details"
Click="Details_Click"
Focusable="False" />
</MenuItem.Header>
</MenuItem>
</Menu.Items>
</Menu>
<Button Content="Details"
Click="Details_Click" />
</StackPanel>