Develop Reference

Binding Errors on collapsed Gui Elements

I have a lot of bindings in a grid which are collapsed or visible based on the selecteditem in a treeview tree. so based on the object, the correct view pops up and the other collapses.
But I get lots of binding errors of the gui elements in the collapsed views. that is so, because I have a "myselecteditem" in the view model that fits to the view which is opened, but not to the collapsed ones.
is my approach stupid? can i suppress bindings for gui elemnts in a collapsed grid?
Code (shorted for lazy readers):
XAML:
<Grid x:Name="G_G_Content" Grid.Column="1">
<Grid x:Name="G_G_Abrechnung_Control" Visibility="Collapsed">
[...]
</Grid>
<Grid x:Name="G_G_Mitglied_Aktion" Visibility="Collapsed">
[...]
</Grid>
<Grid x:Name="G_G_Mitglied_Aktion_Nachweis" Visibility="Visible">
[...]
</Grid>
</Grid>
<TreeView
x:Name="G_tv_explorer"
Grid.Row="1"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
ItemsSource="{Binding TreeViewItemSource, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
SelectedItemChanged="G_tv_explorer_SelectedItemChanged"
TreeViewItem.Expanded="TreeViewItem_Expanded" />
C#:
private void G_tv_explorer_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
//set active treeviewitem
if (G_tv_explorer.SelectedItem != null)
{
//set treeview && ViMo
ViMo.TreeViewSelectedItem = e.NewValue;
RedrawGui();
ViMo.MySelectedItem = ((TreeViewItem)e.NewValue).Tag;
}
}
public void RedrawGui()
{
//redraw gui, dependant on selectedtreeviewitem
if (ViMo.TreeViewSelectedItem != null)
{
if(ViMo.TreeViewSelectedItem is string)
MessageBox.Show("Dummy");
else
{
//this is a placeholder
if (((TreeViewItem)ViMo.TreeViewSelectedItem).Header.ToString() == "Verwaltung")
{
G_G_Mitglied_Aktion_Nachweis.Visibility = System.Windows.Visibility.Collapsed;
G_G_Abrechnung_Control.Visibility = System.Windows.Visibility.Visible;
}
else if (((TreeViewItem)ViMo.TreeViewSelectedItem).Tag is MVVM.Model.Jahresabschluss)
{
G_G_Mitglied_Aktion_Nachweis.Visibility = System.Windows.Visibility.Collapsed;
G_G_Abrechnung.Visibility = System.Windows.Visibility.Visible;
}
}
}
}
Where RedrawGUI only sets the Grids Visible / collapsed based on the Object Type of the SelectedItem

WPF "Hidden" behind a Panel

I am encountering an issue in my project and i don't have much more time to do research.
The goal of this project is to allow attending to tests without being physically present.
You receive a file containing your tests, you attend to them (time limited) and send back the file containing your answers.
I got a TextBox in a StackPanel, itself contained in another StackPanel.
All the controls are created programatically.
The controls are added correctly but the TextBox don't react to mouse input.... (in fact only when the textbox is the ast item and even ther only the little last pixel)
UserControl XAML file :
<UserControl x:Class="DataLibrary.View.Questions.ListQuestionInterface"
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:localization ="clr-namespace:DataLibrary.Resources"
xmlns:convert ="clr-namespace:DataLibrary.View.Converters"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300"
Loaded="ListQuestionInterface_OnLoaded">
<UserControl.Resources>
<localization:LocalizedStrings x:Key="LocalizedStrings"/>
<convert:getVisible x:Key="getVisible"/>
<convert:getText x:Key="getText"/>
</UserControl.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="10*"/>
<RowDefinition Height="40"/>
</Grid.RowDefinitions>
<StackPanel VerticalAlignment="Stretch" Orientation="Horizontal" x:Name="body" Grid.Row="0" FocusManager.IsFocusScope="True"/>
<Label Grid.Row="0" Margin="0,10,0,0" x:Name="explanations"/>
<Button Content="{Binding Path=type, Converter={StaticResource getText}}"
HorizontalAlignment="Right"
Margin="0,0,10,10"
VerticalAlignment="Bottom"
Grid.Row="1"
Width="120"
Height="20"
Click="DisplayAnswerButton_Click"
Visibility="{Binding Path=type, Converter={StaticResource getVisible}}"/>
</Grid>
</UserControl>
Code Behind:
public partial class ListQuestionInterface : UserControl
{
private UIElement _firstElement;
ListQuestion q;
private bool isTest;
public questionType type
{
get
{
return q.Type;
}
set
{
Console.WriteLine("Attempted to write questionType");
}
}
public ListQuestionInterface(ListQuestion question, bool isTest = true)
{
InitializeComponent();
this.explanations.Content = question.Explanation;
this.DataContext = this;
this.q = question;
this.isTest = isTest;
refreshStackPanel();
}
private void refreshStackPanel()
{
bool first = true;
this.body.Children.Clear();
var enumerators = new Hashtable();
foreach (Question subQuestion in this.q.SubQuestions)
{
enumerators.Add(subQuestion, subQuestion.interfaceEnumerator(isTest).GetEnumerator());
((IEnumerator)enumerators[subQuestion]).MoveNext();
}
//If the Alignemnt property has a value we'll want each pair of control to be aligned wit heach other
//if not, we just want them stacked to the left
if (q.Alignment.HasValue)
{
int maxCount = this.q.SubQuestions.Max(x => x.interfaceEnumerator(isTest).Count());
for (int i = 0; i < maxCount; i++)
{
var stack = new StackPanel
{
VerticalAlignment = VerticalAlignment.Stretch,
HorizontalAlignment = HorizontalAlignment.Center
};
foreach (Question subQuestion in this.q.SubQuestions)
{
try
{
var enumerator = (IEnumerator)enumerators[subQuestion];
var control = enumerator.Current as Control;
((Panel)VisualTreeHelper.GetParent(control)).Children.Remove(control);
control.HorizontalAlignment = q.Alignment.Value;
Canvas canvas = null;
if (control.GetType() == typeof(Button) || control.GetType() == typeof(MaskedTextBox))
{
canvas = new Canvas();
if (control.GetType() == typeof(MaskedTextBox))
{
var thick = control.Margin;
thick.Left -= 5;
control.Margin = thick;
}
if (first)
{
this._firstElement = control;
first = false;
}
control.Focusable = true;
canvas.Children.Add(control);
}
if (canvas == null)
{
stack.Children.Add(control);
}
else
{
stack.Children.Add(canvas);
}
enumerator.MoveNext();
}
catch
{
var blank = new Label
{
Content = "BLANK",
Visibility = Visibility.Hidden
};
stack.Children.Add(blank);
Console.WriteLine("No more items to display");
}
}
this.body.Children.Add(stack);
}
}
else
{
var stack = new StackPanel
{
VerticalAlignment = VerticalAlignment.Stretch,
HorizontalAlignment = HorizontalAlignment.Center,
};
foreach (var subQuestion in q.SubQuestions)
{
var subStack = new StackPanel
{
VerticalAlignment = VerticalAlignment.Stretch,
HorizontalAlignment = HorizontalAlignment.Left,
Orientation = Orientation.Horizontal
};
var enumerator = subQuestion.interfaceEnumerator(isTest).GetEnumerator();
while (enumerator.MoveNext())
{
var control = enumerator.Current as Control;
control.HorizontalAlignment = HorizontalAlignment.Left;
if (control.GetType() == typeof(Button) || control.GetType() == typeof(MaskedTextBox))
{
if (first)
{
this._firstElement = control;
first = false;
}
control.Focusable = true;
}
((Panel)VisualTreeHelper.GetParent(control)).Children.Remove(control);
subStack.Children.Add(control);
}
stack.Children.Add(subStack);
}
this.body.Children.Add(stack);
}
}
private void DisplayAnswerButton_Click(object sender, RoutedEventArgs e)
{
foreach (Question question in q.SubQuestions)
{
question.DisplayAnswers();
}
refreshStackPanel();
}
private void ListQuestionInterface_OnLoaded(object sender, RoutedEventArgs e)
{
this._firstElement.Focus();
}
}
}
I don't think the button have somethng to do with the problem so i'll leave the converters code away.
I've checked some things already :
IsHitTestVisible is never set to false
Defining one of the stackpanels as the FocusScope don't change anything
If i place all my controls into canvas and the canvas into the stackpanel i can freely click on my controls but their placement is completely broken.
The Actual Width/height of the control is sufficient to interact with them(60x20)
The problem seems to have appeared just after using the following trick to set a first focused element on other UserControls (which are not in the current VisualTree anymore)
I really do need help since i can't seem to find someone with a similar problem.
And here are two screenshots to illustrate the problem :
The black arrows shows where my i clicked before taking the screenshot (btw if you know of any software that can do a screenshot WITH the mouse i'm taking it :) )

Ok, my fault here -_-'
I was so tired that i didnt't see that my stackpanel was in fact really BEHIND a Label
In my code i only had 2 row definitions, in the first i put the stackpanel AND a Label (who took the entire space).
And because it was declared later, the label was above the stackpanel thus preventing any mouse interaction with it's content.
Here is the corrected XAML :
<UserControl x:Class="DataLibrary.View.Questions.ListQuestionInterface"
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:localization ="clr-namespace:DataLibrary.Resources"
xmlns:convert ="clr-namespace:DataLibrary.View.Converters"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300"
Loaded="ListQuestionInterface_OnLoaded">
<UserControl.Resources>
<localization:LocalizedStrings x:Key="LocalizedStrings"/>
<convert:getVisible x:Key="getVisible"/>
<convert:getText x:Key="getText"/>
</UserControl.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="60*"/>
<RowDefinition Height="20*"/>
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<StackPanel VerticalAlignment="Stretch" Orientation="Horizontal" x:Name="body" Grid.Row="0" FocusManager.IsFocusScope="True"/>
<Label Grid.Row="1" Margin="0,10,0,0" x:Name="explanations"/>
<Button Content="{Binding Path=type, Converter={StaticResource getText}}"
HorizontalAlignment="Right"
Margin="0,0,10,10"
VerticalAlignment="Bottom"
Grid.Row="2"
Width="120"
Height="20"
Click="DisplayAnswerButton_Click"
Visibility="{Binding Path=type, Converter={StaticResource getVisible}}"/>
</Grid>
</UserControl>
So in fact, the control was really hidden behind another one -_-'
I now know that this isn't the WPF way of doing things, but i do not know yet how to DataBind to a Template properly
I'm still taking any advices on a good tutorial/starting point for binding to a DataTemplate in XAML, tho only DataBindings i could find were for binding single values to control properties

How to show tooltip in code behind in WPF

How can I show a tooltip in code-behind? The code below defines my question better. Obviously I don't want the code to check for mouse position etc, just how to display the tooltip.
private void UIElement_OnMouseMove(object sender, MouseEventArgs e)
{
// if mouse position equals certain coordinates show the tooltip
}

Try like this:
if (control.ToolTip != null)
{
// Main condition
if (control.ToolTip is ToolTip)
{
var castToolTip = (ToolTip)control.ToolTip;
castToolTip.IsOpen = true;
}
else
{
toolTip.Content = control.ToolTip;
toolTip.StaysOpen = false;
toolTip.IsOpen = true;
}
}
The Main condition necessary, because ToolTip for Control can be set in two approaches:
First approach
<Button Name="TestButton"
ToolTip="TestToolTip" />
This approach is most common. In this case, the content of the ToolTip will object and not type of ToolTip.
Second approach
<Button Name="TestButton"
Content="Test">
<Button.ToolTip>
<ToolTip>TestToolTip</ToolTip>
</Button.ToolTip>
</Button>
Is the same as this:
<Button Name="TestButton"
Content="Test">
<Button.ToolTip>
TestToolTip
</Button.ToolTip>
</Button>
In this case, the Content type of ToolTip will be Tooltip. Note that in the second case, the object automatically fills ToolTip object on line TestToolTip, hence this approach will work a bit slower.
Therefore, this check is needed to avoid an exception when we try to assign to the ToolTip the content of the ToolTip type here:
toolTip.Content = control.ToolTip;
Below is a full example:
XAML
<Grid>
<Button Name="TestButton"
Width="100"
Height="25"
Content="Test"
ToolTip="TestToolTip" />
<Button Name="ShowToolTip"
VerticalAlignment="Top"
Content="ShowToolTip"
Click="ShowToolTip_Click" />
</Grid>
Code-behind
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void ShowToolTip_Click(object sender, RoutedEventArgs e)
{
var toolTip = new ToolTip();
if (TestButton.ToolTip != null)
{
if (TestButton.ToolTip is ToolTip)
{
var castToolTip = (ToolTip)TestButton.ToolTip;
castToolTip.IsOpen = true;
}
else
{
toolTip.Content = TestButton.ToolTip;
toolTip.StaysOpen = false;
toolTip.IsOpen = true;
}
}
}
}

Is it possible to make a Popup act as a Layered Window

I am wonder if a PopUp can be A LayeredWindow.
I am using Encoder 4 and there is a property that allows the program to not capture layered window.
Here is my code to show the feed in a tooltip
public class MyToolTip : ToolTip
{
protected override void OnTemplateChanged(ControlTemplate oldTemplate, ControlTemplate newTemplate)
{
if (newTemplate != null)
{
this.Visibility = Visibility.Collapsed;
this.IsOpen = true;
Popup popup = GetPopupFromVisualChild(this);
if (popup != null)
{
popup.AllowsTransparency = false;
}
this.IsOpen = false;
this.Visibility = Visibility.Visible;
}
}
private static Popup GetPopupFromVisualChild(Visual child)
{
Visual parent = child;
FrameworkElement visualRoot = null;
while (parent != null)
{
visualRoot = parent as FrameworkElement;
parent = VisualTreeHelper.GetParent(parent) as Visual;
}
Popup popup = null;
if (visualRoot != null)
{
popup = visualRoot.Parent as Popup;
}
//popup.
return popup;
}
}
Wpf :
<Grid>
<Button Width="10" Height="10" Click="Button_Click">
<Button.ToolTip>
<w:MyToolTip Height="500" Width="550" StaysOpen="True">
<WindowsFormsHost x:Name="wrapper" Margin="0,0,0,0" Background="{x:Null}">
<wf:Panel x:Name="previewScreen" BackColor="Transparent" Size="500,500" >
<wf:Panel.Controls>
<wf:Panel x:Name="PreviewScreen2" BackColor="Transparent" Size="500,500"></wf:Panel>
</wf:Panel.Controls>
</wf:Panel>
</WindowsFormsHost>
</w:MyToolTip>
</Button.ToolTip>
</Button>
</Grid>
This issue is Encoder 4, only accept a HandleRef for the preview window.
This is what i DO with Encoder :
MediaSource is a LiveDeviceSource
if (mediaSource != null && mediaSource.PreviewWindow == null)
mediaSource.PreviewWindow =
new PreviewWindow(new HandleRef(PreviewWindow.PreviewScreen2, PreviewWindow.PreviewScreen2.Handle));
What i want is to have a tooltip that shows the webcam preview but not being recorded with the screen.
If I Don't use the Popup, the feed doesn't show. Altought Encoder understand it's a LayeredWindow and doesn't record it.
If I use the popup the feed shows but it's being recorded.
Somehow it's not a layeredWindow anymore even if it's in a tooltip.
Some help would be greatly apprecied, and rewarded =)

Allowing SizeToContent to enlarge the size but not reduce it

I have a window with a tabbed control inside, which contains controls of different sizes in each tab. I'm using SizeToContent="WidthAndHeight" in my Window, but I would like to allow it to only enlarge the window size.
For example, if I move to a 'bigger' tab, I want my control to adapt its size automatically, but if I then go back to the 'smaller' tab, I don't want my control to reduce its size again. I would prefer to not use MinWidth and MinHeight as I would like that my users are able to manually reduce the window size.
Thank you

This is a working example;
The Xaml:
<Window x:Class="WpfApplicationUpper.Window3"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window3" Height="300" Width="300" SizeToContent="WidthAndHeight">
<Grid>
<TabControl Name="MainTabControl"
SelectionChanged="MainTabControl_SelectionChanged"
PreviewMouseDown="MainTabControl_PreviewMouseDown">
<TabItem Header="Small Tab" >
<Border Background="AliceBlue" Width="200" Height="200" />
</TabItem>
<TabItem Header="Medium Tab">
<Border Background="Blue" Width="400" Height="400" />
</TabItem>
<TabItem Header="Large Tab">
<Border Background="Navy" Width="600" Height="600" />
</TabItem>
</TabControl>
</Grid>
</Window>
The code behind:
public partial class Window3 : Window
{
public Window3() {InitializeComponent();}
double _currentWidth;
double _currentHeight;
private void MainTabControl_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
TabItem currentItem = MainTabControl.SelectedItem as TabItem;
FrameworkElement content = currentItem.Content as FrameworkElement;
_currentWidth = content.ActualWidth;
_currentHeight = content.ActualHeight;
}
private void MainTabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
TabItem itemAdded = null;
TabItem itemRemoved = null;
if (e.AddedItems.Count > 0)
itemAdded = e.AddedItems[0] as TabItem;
if (e.RemovedItems.Count > 0)
itemRemoved = e.RemovedItems[0] as TabItem;
if (itemAdded != null && itemRemoved != null)
{
FrameworkElement content = itemAdded.Content as FrameworkElement;
double newWidth = content.Width;
double newHeight = content.Height;
if (newWidth < _currentWidth)
content.Width = _currentWidth;
if (newHeight < _currentHeight)
content.Height = _currentHeight;
}
}
}
I know this is a little ugly, but it is better that nothing :)