Develop Reference

WPF: Can't change property of custom control inside other control template (+Pictures)

Let's create an empty WPF project.
Add a very simple UserControl (i named it MyUserControl):
<UserControl x:Class="Delete_This_Test.MyUserControl"
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"
mc:Ignorable="d"
Background="Red"
Height="100">
<Grid>
</Grid>
</UserControl>
As you can see, i have changed only 2 properties: Background and Height to "Red" and "100".
Put our created control in MainWindow:
<Window x:Class="Delete_This_Test.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:Delete_This_Test"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid>
<local:MyUserControl Width="100"
Height="200"
Background="Blue">
</local:MyUserControl>
</Grid>
</Window>
Here, i have changed Width, Height and Background to "100", "200" and "Blue".
And it works: Without ControlTemplate Picture
But if we put MyUserControl in some ControlTemplate, for example of Button:
<Window x:Class="Delete_This_Test.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:Delete_This_Test"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid>
<Button>
<Button.Template>
<ControlTemplate TargetType="Button">
<local:MyUserControl Width="100"
Height="200"
Background="Blue">
</local:MyUserControl>
</ControlTemplate>
</Button.Template>
</Button>
</Grid>
</Window>
This will not work. Only Width property will changed, because we didn't set it in MyUserControl xaml.
Height and Background will be the same as "100" and "Red":
With ControlTemplate Picture
So my question is: Is it bug of WPF, or i'm missing something obvious?
*
Because i need to use one custom control in different templates, and change some properties, e.g. Background of control

How to remove border when WindowStyle="None" AllowsTransparency=“False” and ResizeMode="CanResize"

I have a window with the following properties
WindowState="Maximized"
WindowStyle="None,
AllowsTransparency="False"
ResizeMode="CanResize"
But the problem is a border appears around the window.
How can I fix it without changing any of these properties
When I set AllowsTransparency True some user controls such as PdfViewer,WebBrowser not displaying contents.
<Window x:Class="WpfApplication8.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
WindowStyle="None"
WindowState="Maximized"
AllowsTransparency="False"
ResizeMode="CanResize"
UseLayoutRounding="True"
Title="MainWindow">
<Grid Background="Red"></Grid>
</Window>

You could use a WindowChrome:
<Window x:Class="WpfApplication8.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
WindowStyle="None"
AllowsTransparency="False"
ResizeMode="CanResize"
UseLayoutRounding="True"
Title="MainWindow">
<WindowChrome.WindowChrome>
<WindowChrome CaptionHeight="0" ResizeBorderThickness="5" />
</WindowChrome.WindowChrome>
<Grid Background="Red"></Grid>
</Window>

Get XAML code in WPF

How can I get XAML code of a window as a string, change this string, and upload this string as a xaml-code of window?
For example, I have
<Window x:Class="WpfApplication1.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:WpfApplication1"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<ComboBox Margin="0,0,9,38" Name="button1" Height="82" HorizontalAlignment="Right" VerticalAlignment="Bottom" Width="132"></ComboBox>
</Grid>
</Window>
and I want to have this xaml code in the end
<Window x:Class="WpfApplication1.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:WpfApplication1"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<ComboBox Margin="0,0,9,38" Name="button1" Height="82" HorizontalAlignment="Right" VerticalAlignment="Bottom" Width="132">
<ComboBox.ItemTemplate>
<DataTemplate>
<local:d_dddw_imp_insurance_list />
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
</Grid>
</Window>

If your using wpf/xaml with c#, visual studio generally compile the xaml code to c#, to be as performant as possible. If you want to have some dynamic XAML, you need to use XamlReader to read xaml and display at "on your own".
Just take a look at: Loading XAML XML through runtime
Than you can change or manipulate the xaml and display the result very easily.

WPF - Update static resource value at runtime

I have code similar to the following:
<Application
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Software_Suite_Maker"
xmlns:System="clr-namespace:System;assembly=mscorlib"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d" x:Class="WpfApplication1.App"
StartupUri="MainWindow.xaml">
<Application.Resources>
<FontFamily x:Key="FontFamilyName">./Fonts/#Segoe UI</FontFamily>
</Application.Resources>
and the Window xaml code is:
<Window x:Class="WpfApplication1.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:WpfApplication1"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<TextBox FontFamily="{StaticResource FontFamilyName}" Margin="135,122,187,180" Text="test"/>
<Button FontFamily="{StaticResource FontFamilyName}" Margin="135,144,329,154" Content="test"/>
</Grid>
Now I want to change the value of FontFamilyName from behind code. I wrote this code:
var font = TryFindResource("FontFamilyName") as FontFamily;
font = new FontFamily("./Fonts/#Tahoma");
But nothing happened and did not change.
My question is: How can I change FontFamilyName value from behind code and changes will also be made on the objects?

You have to use a DynamicResource for that :
<TextBox FontFamily="{DynamicResource FontFamilyName}" Margin="135,122,187,180"
Text="test"/>
<Button FontFamily="{DynamicResource FontFamilyName}" Margin="135,144,329,154"
Content="test"/>
Read on MSDN about DynamicResource:
Provides a value for any XAML property attribute by deferring that value to be a reference to a defined resource. Lookup behavior for that resource is analogous to run-time lookup.

Showing a control based on type of databound viewmodel?

I'm learning WPF at the moment. I'm finding xaml quite tough to use. I have MainWindow.xaml defined like this:
<Window x:Class="Compliance.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">
<Window.Resources>
<ResourceDictionary Source="MainWindow.Resources.xaml"></ResourceDictionary>
</Window.Resources>
<Grid>
</Grid>
</Window>
And MainWindow.Resources.xaml like this:
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:Compliance.ViewModel"
xmlns:vw="clr-namespace:Compliance.View">
<DataTemplate DataType="{x:Type vm:Entities.AbstractEntityViewModel}">
<vw:AbstractEntityView></vw:AbstractEntityView>
</DataTemplate>
</ResourceDictionary>
AbstractEntityView is like this:
<UserControl x:Class="Compliance.View.AbstractEntityView"
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"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<StackPanel>
<Label Content="ID:"></Label>
<TextBlock Text="{Binding Path=EntityId}"></TextBlock>
</StackPanel>
</UserControl>
Then in App.xaml.cs I am overriding OnStartup like this:
MainWindow window = new MainWindow();
//Model class
Individual ind = new Individual(1,"Name");
//subclass of AbstractEntityViewModel
var vm = new Entities.IndividualEntityViewModel(ind);
window.DataContext = vm;
window.Show();
However, nothing appears in the window.
I used the answer from this question to get my control to render. However, this requires you to refer to elements in the view from the code, which I don't want to do.
Is it possible to get a window to pick a View to render based on the ViewModel set as its datacontext? Or do I have the wrong idea about how MVVM is supposed to work?

You have the right idea, but you're not actually telling WPF to display your ViewModel anywhere
I usually host a ViewModel in a ContentControl object if I am binding to a single ViewModel
<Window x:Class="Compliance.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">
<Window.Resources>
<ResourceDictionary Source="MainWindow.Resources.xaml"></ResourceDictionary>
</Window.Resources>
<Grid>
<ContentControl Content="{Binding }" />
</Grid>
</Window>
The ContentControl is usually not needed for lists of Models or ViewModels, since the object is automatically inserted as the Content property of the ContentPresenter of each item. For example, no ContentControl is needed when binding a ListBox to a collection of ViewModels
<ListBox ItemsSource="{Binding MyCollectionOfViewModel}" />