Develop Reference

Is there a way a TextBox loses focus when clicking on the background in Caliburn Micro?

When trying to rebuild a WPF Application to use Caliburn Micro I experienced that a TextBox does not loose focus when you click outside of it. Is there a fix for that behaviour?
I am using Caliburn Micro 3.2.0. I tried using older versions but this problem persits.
XAML:
<Window x:Class="WPFUI.Views.ShellView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WPFUI.Views"
xmlns:cal="http://www.caliburnproject.org"
mc:Ignorable="d"
Title="ShellView" Height="450" Width="800">
<Grid>
...
<WrapPanel>
<TextBox x:Name="Name" MinWidth="50"
cal:Message.Attach="[Event LostFocus] = [Action Name_LostFocus()];
[Event PreviewTextInput] = [Action Name_PreviewTextInput($source, $eventArgs)]">
</TextBox>
...
</WrapPanel>
...
</Grid>
</Window>

I assume this is a case where you do not have any other Element in the Window other than the Textbox, which is why it cannot lose focus. One way to achieve this is to make the Window Focusable and setting Focus to it using a behavior.
For Example, assuming your Xaml to be as follows
<Window x:Class="CM.WPFApp2019.Views.ShellView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:cal="http://www.caliburnproject.org"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:CM.WPFApp2019.Views"
xmlns:i = "http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:behaviors="clr-namespace:CM.WPFApp2019.ViewModels"
mc:Ignorable="d" Focusable="True"
Title="ShellView" Height="450" Width="800">
<i:Interaction.Behaviors>
<behaviors:ClearFocusOnClickBehavior ElementToClearFocus="{Binding ElementName=Name}"/>
</i:Interaction.Behaviors>
<Grid>
<WrapPanel>
<TextBox x:Name="Name" MinWidth="50" Focusable="True"
cal:Message.Attach="[Event LostFocus] = [Action Name_LostFocus()];
[Event PreviewTextInput] = [Action Name_PreviewTextInput($source, $eventArgs)]">
</TextBox>
</WrapPanel>
</Grid>
</Window>
Please note I have added a Behavior called ClearFocusOnClickBehavior to the Window. Also you have set the Focusable Property of Window to be true.
Now you can define the behavior as follows
public class ClearFocusOnClickBehavior : Behavior<FrameworkElement>
{
public static readonly DependencyProperty ElementToClearFocusProperty = DependencyProperty.RegisterAttached("ElementToClearFocus", typeof(FrameworkElement),
typeof(ClearFocusOnClickBehavior), new UIPropertyMetadata());
public FrameworkElement ElementToClearFocus
{
get { return (FrameworkElement)GetValue(ElementToClearFocusProperty); }
set { SetValue(ElementToClearFocusProperty, value); }
}
protected override void OnAttached()
{
AssociatedObject.MouseDown += (sender, args) =>
{
FrameworkElement ctrl = ElementToClearFocus;
FrameworkElement parent = (FrameworkElement)ElementToClearFocus.Parent;
while (parent != null && parent is IInputElement
&& !((IInputElement)parent).Focusable)
{
parent = (FrameworkElement)parent.Parent;
}
DependencyObject scope = FocusManager.GetFocusScope(ElementToClearFocus);
FocusManager.SetFocusedElement(scope, parent as IInputElement);
};
base.OnAttached();
}
}
The Behavior would add a MouseDown event for the associated object, where you could trace the Parent of the ElementToClearFocus Control which can be Focused. In this case, since you have set the Window as focusable, it would receive the Focus. The Textbox in turn loses the focus and raises the Name_LostFocus method

How to get C# WPF MVVM Screensaver use dual monitor?

I am looking for an answer howto get a C#-WPF-MVVM-Screensaver-View on dual and more monitors running. I read several tutorials on webpages and answers here. However, never the coding samples worked on wpf.
Have someone a code exmple that works for wpf and Model View ViewModel Pattern?
I appreciate your help and thank you.

Thanks. I did it on Windows 10.
Create new WPF Window project for C#
Remove the startupuri / startuplocation from app.xaml.
Add a startup method to app.xaml.
4.
<Application x:Class="SeveralDisplays.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:SeveralDisplays"
Startup="OnStartup">
<Application.Resources>
</Application.Resources>
</Application>
using System.Drawing;
using System.Windows;
using System.Windows.Forms;
using Application = System.Windows.Application;
namespace SeveralDisplays
{
/// <summary>
/// Interaction logic for App.xaml
/// </summary>
public partial class App : Application
{
private void OnStartup(object sender, StartupEventArgs e)
{
Window mainWindow1 = new MainWindow();
Window mainWindow2 = new MainWindow2();
Screen s1 = Screen.AllScreens[0];
Screen s2 = Screen.AllScreens[1];
Rectangle r1 = s1.WorkingArea;
Rectangle r2 = s2.WorkingArea;
mainWindow1.Top = r1.Top;
mainWindow1.Left = r1.Left;
mainWindow2.Top = r2.Top;
mainWindow2.Left = r2.Left;
mainWindow1.Show();
mainWindow2.Show();
mainWindow2.Owner = mainWindow1;
}
}
}
add two classes and ensure they are window-classes.
First / Main view, do not change here too much
<Window x:Class="SeveralDisplays.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:SeveralDisplays"
mc:Ignorable="d"
Loaded="MainWindow_OnLoaded"
Title="MainWindow" Height="350" Width="525">
<Grid>
</Grid>
</Window>
first window code behind
using System.Windows;
namespace SeveralDisplays
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void MainWindow_OnLoaded(object sender, RoutedEventArgs e)
{
WindowState = WindowState.Maximized;
WindowStyle = WindowStyle.None;
ShowInTaskbar = false;
}
}
}
Second xaml as window
<Window x:Class="SeveralDisplays.MainWindow2"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:SeveralDisplays"
mc:Ignorable="d"
Title="MainWindow2"
WindowStartupLocation="Manual"
WindowStyle="None"
WindowState="Maximized"
Height="300" Width="300">
<Grid>
</Grid>
</Window>
Code behind:
using System.Windows;
namespace SeveralDisplays
{
public partial class MainWindow2 : Window
{
public MainWindow2()
{
InitializeComponent();
}
}
}

you can do this simplified and smart. I use only a method inside app.xaml.cs
/// <summary>
/// Shows the screensaver on every monitor. This is a multi monitor
/// application.
/// </summary>
private void ShowScreenSaver()
{
ClockWindow ownerWindow = null;
// Creates window on other screens.
foreach (System.Windows.Forms.Screen screen in System.Windows.Forms.Screen.AllScreens)
{
ClockWindow window = new ClockWindow(screen.Bounds.Width,
screen.Bounds.Height);
// Primary screen does not have WindowsStartupLocation.
if (screen.Primary)
{
// Maximizes screen.
window.WindowState = WindowState.Maximized;
ownerWindow = window;
}
else
{
// Other screens need a WindowStartupLocation on manual.
window.WindowStartupLocation = WindowStartupLocation.Manual;
System.Drawing.Rectangle location = screen.Bounds;
window.Top = location.Top;
window.Left = location.Left - 480;
window.Width = location.Width;
window.Height = location.Height;
}
window.Show();
}
// Sets every other screen owned to prmary window.
// It closes all windows at once.
foreach (Window window in Current.Windows)
{
if (window != ownerWindow)
{
window.Owner = ownerWindow;
}
}
}
Here I added a View, which I initializes for several displays.
<Window x:Class="Clock_ScreenSaver.Views.ClockWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:Clock_ScreenSaver.Views"
mc:Ignorable="d"
Title="ClockWindow"
Height="{Binding DisplayHeight}"
Width="{Binding DisplayWidth}"
AllowsTransparency="True"
Background="Black"
Cursor="None"
ShowInTaskbar="False"
KeyDown="ClockWindow_KeyDown"
MouseMove="ClockWindow_MouseMove"
MouseDown="ClockWindow_MouseDown"
Closing="ClockWindowClosing"
Loaded="ClockWindowLoaded"
WindowStyle="None"
ResizeMode="NoResize">
<Grid Name="WindowGrid">
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="300"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="300"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Border Grid.Row="1" Grid.Column="1" CornerRadius="360" BorderBrush="#FFDF66" BorderThickness="5" Background="#2D2D30">
<StackPanel>
<Label Foreground="#FFDF66" Margin="0,15,0,0" FontSize="25" FontFamily="Arial" HorizontalAlignment="Center">DIGICLOCK</Label>
<StackPanel Background="#3F3F46" Margin="0,20,0,5" Width="280" Height="100">
<Label Content="{Binding ClockTime}" Name="timelbl" Margin="0,20,0,0" Foreground="#FFDF66" FontSize="40" FontFamily="Arial" HorizontalAlignment="Center"></Label>
</StackPanel>
<StackPanel Background="#3F3F46" Margin="0,0,0,10" Width="280" Height="50">
<Label Content="{Binding ClockDate}" Name="datelbl" Margin="0,8,0,0" Foreground="#FFDF66" FontSize="20" FontFamily="Arial" HorizontalAlignment="Center"></Label>
</StackPanel>
<Button Width="60" Padding="5,5,5,5" Background="#FFDF66" FontSize="10" FontFamily="Arial" Foreground="#333333" BorderThickness="0" Name="QuitBtn" Click="QuitBtn_Click">
Quit
</Button>
</StackPanel>
</Border>
</Grid>
</Window>

WPF data binding is not working for second usage

I'm using GalaSoft.MvvmLight.Messaging for communication between classes.
From my ViewModel I'm asking for an object of type view to use it as the content of my DialogHost ( part of the MaterialDesign Framework ):
ViewModel:
Messenger.Default.Send(new NotificationMessage("dialogFormOpenStaple"));
-
private void DialogReceived(string msg, object param)
{
if (msg == "dialogFormOpenStaple")
{
this.dialogContent = param;
this.isDialogOpen = true;
}
}
View
private void NotificationMessageReceived(string msg)
{
if (msg == "dialogFormOpenStaple")
{
object content = new dialogEditMode();
Messenger.Default.Send(new NotificationMessage<object>(content, "dialogFormOpenStaple"));
}
}
All this is working fine. In my XAML itself I got some button bindings to RelayCommands.
<UserControl x:Class="kati2._0.production.dialogEditMode"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:kati2._0.production"
mc:Ignorable="d"
>
[...]
<Button Margin="8 0 0 0" Style="{DynamicResource MaterialDesignFlatButton}" Foreground="#FF757476" IsDefault="True" Command="{Binding dialogOpenStapleNo}">No</Button>
[...]
</UserControl>
Those RelayCommands are defined in my ViewModel. When I open die Dialog for the first time and click on the button it's working fine. If I try it a second time the dialog also opens up but the click event is not getting triggered.

NullReferenceException loading RenderWindowControl for vtk in WPF

I am trying to load a RenderWindowControl from vtk libraries on my WPF proyect using ActiViz.NET and Visual Studio 2013. The library works fine since I did a new project just to practice on itbut when I tried to integrate it into my work, I got a null RenderWindowControl this time. This is my code:
MainWindow.xaml:
<Window x:Class="myProject.Views.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:VtkTab="clr-namespace:myProject.Views.UITabs.VtkTab"
x:Name="Mainwindow"
MinHeight="600"
MinWidth="800"
Title="{Binding Title}"
Height="720"
Width="1280"
Icon="{StaticResource ApplicationIcon}"
Loaded="OnLoaded"
DataContext="{Binding Main, Source={StaticResource ViewModelLocator}}"
Style="{StaticResource WindowStyle}"
mc:Ignorable="d">
<DockPanel>
<TabControl>
....
....
<VtkTab:VtkTabView />
....
....
</TabControl>
</DockPanel>
</Window>
VtkTabView.xaml:
<UserControl x:Class="myProject.Views.UITabs.VtkTab.VtkTabView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vtk="clr-namespace:Kitware.VTK;assembly=Kitware.VTK"
Loaded="WindowLoaded"
Height="480" Width="640">
<WindowsFormsHost Name="Wfh">
<vtk:RenderWindowControl x:Name="RenderControl" />
</WindowsFormsHost>
</UserControl>
VtkTabView.xaml.cs:
public partial class UITabView
{
protected static Random _random = new Random();
vtkActor actor = vtkActor.New();
public VtkTabView()
{
InitializeComponent();
var sphere = vtkSphereSource.New();
sphere.SetThetaResolution(8);
sphere.SetPhiResolution(16);
var shrink = vtkShrinkPolyData.New();
shrink.SetInputConnection(sphere.GetOutputPort());
shrink.SetShrinkFactor(0.9);
var move = vtkTransform.New();
move.Translate(_random.NextDouble(), _random.NextDouble(), _random.NextDouble());
var moveFilter = vtkTransformPolyDataFilter.New();
moveFilter.SetTransform(move);
moveFilter.SetInputConnection(shrink.GetOutputPort());
var mapper = vtkPolyDataMapper.New();
mapper.SetInputConnection(moveFilter.GetOutputPort());
// The actor links the data pipeline to the rendering subsystem
actor.SetMapper(mapper);
actor.GetProperty().SetColor(1, 0, 0);
}
private void WindowLoaded(object sender, RoutedEventArgs e)
{
var renderer = RenderControl.RenderWindow.GetRenderers().GetFirstRenderer();
renderer.AddActor(actor);
}
}
RenderControl.RenderWindow is null on WindowLoaded (VtkTabView.xaml.cs) and I do not know why. Might it be because I load UITabView from a second xamp and I lose the content of RenderControl?, it is the only difference I see compare to the example I did.

Access the RenderWindow on Load event of the RenderWindowControl.
e.g.
public VtkTabView()
{
InitializeComponent();
// initialize your sphrere and actor
RenderControl.Load += MyRenderWindowControlOnLoad;
}
private void MyRenderWindowControlOnLoad(object sender_in, EventArgs eventArgs_in){
//access the RenderWindow here
}

How to display a pop-up?

I created a pop-up and want to show it when a button has been clicked. But it doesn't work because it waits for finishing button's duty.
I don't want to use "timer, thread and background worker" because I already can do it with that. I am looking for an another solution…
Here is my code:
void btnSearch_Click(object sender, RoutedEventArgs e)
{
LoadingOpen();
if (cmbvideoserver.Text == "Youtube")
SearchInYoutube();
else if (cmbvideoserver.Text == "Vimeo")
SearchInVimeo();
LoadingClose();
}
public void LoadingOpen()
{
myPopup.IsOpen = true;
Common.Popup = true;
window.Opacity = 0.3;
}
public void LoadingClose()
{
myPopup.IsOpen = false;
Common.Popup = false;
window.Opacity = 1;
}
and the XAML:
<Window Name="window" x:Class="youtube.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" Loaded="window_Loaded">
<Canvas Name="main">
<Popup Name="myPopup" IsOpen="False" PopupAnimation="Slide"
Margin="100,10,20,0" Placement="Center" >
<Label Content="Loading..."></Label>
</Popup>
</Canvas>
</Window>
How can I show popup on my main window ? (without any thread,timer and background controls/classes)

You can show Windows as dialogs by useing the ShowDialog() method.