Develop Reference

WPF TabControl header issue

I am making an app in WPF that displays an image which can be dragged and zoomed. Bottom, right and upper sides contain some UI elements like buttons and in the center I have a TabControl to which I add TabItems in the code of ViewModel. These TabItems consists of their content (an image) and a header where I have tab buttons. The problem I have is that an image I drag covers the header but not the buttons as you can see on the screenshot. The behavior I expect is to have this image hidden underneath the entire header, not only buttons. It only happens with the bottom side. When I drag the image to the top or right it gets hidden behind the sides like it's supposed to.
Header issue
I tried to change its background, opacity and ZIndex but nothing worked for me.
Here is my code.
XAML:
<TabControl Grid.Row="1" Grid.Column="0" TabStripPlacement="Bottom" Background="LightGray" ItemsSource="{Binding LayoutTabs}"
SelectedIndex="0" SelectedItem="{Binding SelectedTab, Mode=OneWayToSource}"/>
C#:
LayoutTabs = new BindableCollection<TabItem>();
for (int i = 0; i < _content.LayoutImages.Count; i++)
{
DrawingImage drawing = _content.LayoutImages.ElementAt(i);
Image image = new Image() { Source = drawing };
image.MouseMove += OnMouseMove;
var container = new LayoutContainer()
{
Background = Brushes.WhiteSmoke,
Child = image,
Focusable = true,
};
var tabItem = new TabItem()
{
Header = _content.GetLayoutName(i),
Content = container
};
LayoutTabs.Add(tabItem);
}

That behaviour is due to the headerpanels background being set to transparent in the default control template. If you right click the tabcontrol in the Designer window (not xaml editor) and click on Edit Template->Edit a Copy you get a copy of that tempalte and can then modify the headerpanel with your BackgroundColor and if need be increase the Zindex:
[....]
//this is the line to make your changes on:
<TabPanel x:Name="headerPanel" Background="Transparent" Grid.Column="0" IsItemsHost="true" Margin="2,2,2,0" Grid.Row="0" KeyboardNavigation.TabIndex="1" Panel.ZIndex="1"/>
[....]

Resizable dialog window in WPF

I use MetroWindow class from Mahapps to show dialog window of some kind.
My idea was to create auto resizable window, to fit it's content size
<controls:MetroWindow
...
DataContext="{Binding DialogVM, Source={StaticResource ViewModelLocator}}"
Title="{Binding WindowHeader}"
WindowTitleBrush="{StaticResource MainStyleTitleBrush}"
Background="{StaticResource MainStyleBackgroundBrush}"
wpfExtensions:SizeObserver.Observe="True"
wpfExtensions:SizeObserver.ObservedWidth="{Binding xHeight, Mode=OneWayToSource}"
wpfExtensions:SizeObserver.ObservedHeight="{Binding xWidth, Mode=OneWay}"
MaxWidth="1110" MaxHeight="1080"
MinWidth="450" MinHeight="600"
ShowMinButton="False"
ShowMaxRestoreButton="False"
BorderThickness="1"
BorderBrush="{StaticResource MainStyleBorderBrush}"
SizeToContent="Width"
WindowStartupLocation="CenterScreen">
<Grid>
<ContentPresenter Content="{Binding VM}"/>
</Grid>
</controls:MetroWindo>
but I have two issues
First one: My window is affected to user actions (Mouse double click on title, drag window to left or right screen edge, and so on), and I want it to be frozen, but resizable.
Second one: when I reshow the same window again (without recreating it, but with new content which can have new visible size) it show's on it's last position.
How can I solve this problems without code-behind WindowSizeChanged event catching?

put ResizeMode="NoResize" and SizeToContent="WidthAndHeight"

Sometimes custom loading popup doesn't show

In my application loading popup is shown every time when I call It. But some times It just doesn't show and it is same situation. Popup is a custom UserControl object made with WPF.
Popup is in MainWindow.xaml:
<Viewbox Stretch="Fill">
<Grid>
<Grid x:Name="Body" Height="768" Width="1024" Background="{StaticResource SCBPassiveColor}" />
<src:InfoPane x:Name="InfoPaneMaster" Visibility="Collapsed" VerticalAlignment="Top" HorizontalAlignment="Center" />
</Grid>
</Viewbox>
In the Body of the main window application loads selected layout/view. Before new layout is loaded program calls :
LayoutCommands.DisplayInfoPane(msgLoginSuccess, ROPInfo.Info, null);
implementation:
public void DisplayInfoPane(string infoText, ROPInfo infoType, int? displayTime)
{
StopTimer();
SetTimer(displayTime ?? DefaultDisplayTime);
PrepareInfoPane(infoText, infoType);
colCloseIcon.Width = new GridLength(0);
this.Visibility = Visibility.Visible;
}
The popup automatically closes (sets visibility to collapsed) after default time.
Why sometimes this popup just doesn't show? Is this associated with rendering?

Make Child control more Opaque than Parent

I have a Page like in the Xaml below which i want to use like a ModalDialog.
The Problem is that when I Pop the Dialog up, that the Opacity of the second Grid which holds the Content is not changed back to 100% and I see from the Page where it is Popuped the underlying controls. For more Detail see the Screenshot.
Is there a way that I can change back the Opacity of the second Grid to 100% that no control behind it can see through?
For completneness I have added the Code which i'm using to bring up the Popup.
ModalDialog Xaml:
<Page>
<Grid x:Name="RootPanel" Background="{StaticResource LucentBlue}" Opacity=".75">
<Border >
<Grid VerticalAlignment="Center"
Height="300" Background="{StaticResource PremiumBlue}" Opacity="1">
</Grid>
</Border>
</Grid>
</Page>
Code Behind Hosted Page:
private Popup _saveDialog;
private void SaveSettingsCommandLogic(object obj)
{
ModalDialog dlg = new ModalDialog();
dlg.CloseRequested += DlgOnCloseRequested;
_saveDialog = new Popup();
_saveDialog.Child = dlg;
_saveDialog.IsOpen = true;
}

Here's a solution in metro :
Please remove the Opacity property of both the elements and from the code behind of the ModalDialog class use the following code:
public ModalDialog()
{
this.InitializeComponent();
Color color = Color.FromArgb(150,255,0,0);
RootPanel.Background = new SolidColorBrush(color);
}
The method FromArgb is used to specify the transparency red green and blue values respectively and can rancge from 0-255 .. please test according to ur convinience :)

C# WPF add control to main window at run time

My goal is to attach a new image control while the application is running.
img = new System.Windows.Controls.Image();
img.Margin = new Thickness(200, 10, 0, 0);
img.Width = 32;
img.Height = 32;
img.Source = etc;
I've tried
this.AddChild(img);// says must be a single element
this.AddLogicalChild(img);// does nothing
this.AddVisualChild(img);// does nothing
It was never this difficult to add a element with forms.
How can I simply attach this new element to the main window (not another control) so that it will show up.
Solved it, I named the grid main, and from there I was able to access the children attribute and the add function
main.children.add(img);
<Window x:Class="Crysis_Menu.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" AllowsTransparency="False" Background="White" Foreground="{x:Null}" WindowStyle="SingleBorderWindow">
<Grid Name="main">
<Button Content="Run" Height="23" HorizontalAlignment="Left" Margin="12,12,0,0" Name="btnRun" VerticalAlignment="Top" Width="151" Click="btnRun_Click" />
<TextBox Height="259" HorizontalAlignment="Left" Margin="12,40,0,0" Name="tbStatus" VerticalAlignment="Top" Width="151" />
</Grid>
</Window>

You should have only one root element under window. Adding the image using this.AddChilda adds the image as child of window, but you probably have some other child defined(Grid for example). Give a name to this child (Grid in the example) and then in the code behind add the image to the Grid
Example :
<Window>
<Grid x:Name="RootGrid">
</Grid>
</Window>
Then in the code behind use
RootGrid.Children.Add(img);

What is this in your case? You can try this.Content = image; or this.Children.Add(image);
If your this is indeed a Window, you should know that Window can have only a single child, which you put into Content. If you want several items in Window, usually you put some appropriate container (for example, Grid or StackPanel) as Window's content, and add children to it.

Vlad got the solution. I used it :
var grid = this.Content as Grid;
// or any controls
Label lblMessage = new Label
{
Content = "I am a label",
Margin = new Thickness(86, 269, 0, 0)
};
grid.Children.Add(lblMessage);