CustomControl with TemplateParts - wpf

Question

I created a CustomControl that has two TemplateParts.
using System;
using System.Windows;
using System.Windows.Controls;
namespace WpfCustomControlLibrary1
{
[TemplatePart(Name = "PART_ControlsLayer", Type = typeof (ContentPresenter))]
[TemplatePart(Name = "PART_DisplayLayer", Type = typeof (ContentPresenter))]
public class CustomControl1 : Control
{
public static readonly DependencyProperty ControlsLayerProperty =
DependencyProperty.Register("ControlsLayer", typeof (object), typeof (CustomControl1),
new UIPropertyMetadata(null));
public static readonly DependencyProperty DisplayLayerProperty =
DependencyProperty.Register("DisplayLayer", typeof (object), typeof (CustomControl1),
new UIPropertyMetadata(null));
private ContentPresenter partControlsLayer;
private ContentPresenter partDisplayLayer;
static CustomControl1()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof (CustomControl1),
new FrameworkPropertyMetadata(typeof (CustomControl1)));
}
public object ControlsLayer
{
get { return GetValue(ControlsLayerProperty); }
set { SetValue(ControlsLayerProperty, value); }
}
public object DisplayLayer
{
get { return GetValue(DisplayLayerProperty); }
set { SetValue(DisplayLayerProperty, value); }
}
public override void OnApplyTemplate()
{
ApplyTemplate();
partControlsLayer = GetTemplateChild("PART_ControlsLayer") as ContentPresenter;
partDisplayLayer = GetTemplateChild("PART_DisplayLayer") as ContentPresenter;
if (partControlsLayer == null || partDisplayLayer == null)
{
throw new NullReferenceException("Template parts not available");
}
}
}
}
In the Generic.xaml I defined the ControlTemplate and a Default-Setter for the DisplayLayer (one of the TemplateParts). Finaly I set this as the Template of CustomControl1.
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfCustomControlLibrary1">
<Style TargetType="{x:Type local:CustomControl1}">
<Style.Resources>
<ControlTemplate x:Key="DefaulTemplate" TargetType="{x:Type local:CustomControl1}">
<Grid>
<ContentPresenter x:Name="PART_ControlsLayer"
Content="{TemplateBinding ControlsLayer}" />
<ContentPresenter x:Name="PART_DisplayLayer"
Content="{TemplateBinding DisplayLayer}" />
</Grid>
</ControlTemplate>
</Style.Resources>
<Setter Property="DisplayLayer">
<Setter.Value>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Label Grid.Row="0" Content="{Binding FunctionName, FallbackValue=Functionname}" />
<TextBlock Grid.Row="1" Text="{Binding DisplayValue, FallbackValue=0.0dB}" Foreground="Lime"
Background="Black" />
</Grid>
</Setter.Value>
</Setter>
<Setter Property="Template" Value="{StaticResource DefaulTemplate}"/>
</Style>
<Style TargetType="{x:Type local:CustomControl2}" BasedOn="{StaticResource {x:Type local:CustomControl1}}" />
</ResourceDictionary>
Now I create a CustomControl2 BasedOn CustomControl1.
using System.Windows;
namespace WpfCustomControlLibrary1
{
public class CustomControl2 : CustomControl1
{
static CustomControl2()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomControl2), new FrameworkPropertyMetadata(typeof(CustomControl2)));
}
}
}
Then I put both Controls on a WpfWindow.
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:wpfCustomControlLibrary1="clr-namespace:WpfCustomControlLibrary1;assembly=WpfCustomControlLibrary1"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<wpfCustomControlLibrary1:CustomControl1 Grid.Row="0"/>
<wpfCustomControlLibrary1:CustomControl2 Grid.Row="1"/>
</Grid>
</Window>
The Problem is I see the Defaulttemplate only on the second Control. I can't find a solution for this, please help.
#gomi42 - if I change Generic.xaml to this:
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfCustomControlLibrary1">
<Style x:Key="BaseStyle" TargetType="{x:Type local:CustomControl1}">
<Style.Resources>
<ControlTemplate x:Key="DefaulTemplate" TargetType="{x:Type local:CustomControl1}">
<Grid>
<ContentPresenter x:Name="PART_ControlsLayer"
Content="{TemplateBinding ControlsLayer}" />
<ContentPresenter x:Name="PART_DisplayLayer"
Content="{TemplateBinding DisplayLayer}" />
</Grid>
</ControlTemplate>
</Style.Resources>
<Setter Property="Template" Value="{StaticResource DefaulTemplate}"/>
<Setter Property="DisplayLayer">
<Setter.Value>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Label Grid.Row="0" Content="{Binding FunctionName, FallbackValue=Functionname}" />
<TextBlock Grid.Row="1" Text="{Binding DisplayValue, FallbackValue=0.0dB}" Foreground="Lime"
Background="Black" />
</Grid>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="{x:Type local:CustomControl1}" BasedOn="{StaticResource BaseStyle}" />
<Style TargetType="{x:Type local:CustomControl2}" BasedOn="{StaticResource BaseStyle}" />
</ResourceDictionary>
nothing changes! It's still visible only in the second control.

Answer 1

The style you created only applies to CustomControl1 because of this:
<Style TargetType="{x:Type local:CustomControl1}">
...
You need to create a new style for CustomControl2 e.g. by inheriting:
<Style x:Key="MyBase" TargetType="{x:Type local:CustomControl1}">
...
</Style>
<Style TargetType="{x:Type local:CustomControl1}" BasedOn={StaticResource MyBase} />
<Style TargetType="{x:Type local:CustomControl2}" BasedOn={StaticResource MyBase} />

Answer 2

I found it!
It's the DependencyProperty which causes the problem. I implemented the CustomControl like the examples on this site:
http://www.kunal-chowdhury.com/2011/04/how-to-implement-template-binding-in.html
and what should I say this example is wrong!
Here is how it works.
First CustomControl.cs
using System;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;
using System.Windows.Controls;
using WpfCustomControlLibrary1.Annotations;
namespace WpfCustomControlLibrary1
{
[TemplatePart(Name = "PART_ControlsLayer", Type = typeof (Grid))]
[TemplatePart(Name = "PART_DisplayLayer", Type = typeof(ContentControl))]
public class CustomControl1 : Control
{
private Grid partControlsLayer;
private ContentControl partDisplayLayer;
static CustomControl1()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof (CustomControl1),
new FrameworkPropertyMetadata(typeof (CustomControl1)));
}
public CustomControl1()
{
DataContext = this;
}
public override void OnApplyTemplate()
{
ApplyTemplate();
partControlsLayer = GetTemplateChild("PART_ControlsLayer") as Grid;
partDisplayLayer = GetTemplateChild("PART_DisplayLayer") as ContentControl;
if (partControlsLayer == null || partDisplayLayer == null)
{
//throw new NullReferenceException("Template parts not available");
}
}
}
}
Then Generic.xaml
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfCustomControlLibrary1">
<Style x:Key="DefaultTemplate" TargetType="{x:Type ContentControl}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ContentControl}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Label Grid.Row="0" Content="{Binding FunctionName, FallbackValue=Functionname}" />
<TextBlock Grid.Row="1" Text="{Binding DisplayValue, FallbackValue=0.0dB}" Foreground="Lime"
Background="Black" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="{x:Type local:CustomControl1}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<ContentControl x:Name="PART_DisplayLayer" Style="{StaticResource DefaultTemplate}" />
<Grid x:Name="PART_ControlsLayer" Grid.Row="1">
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Button Grid.Row="0" Content="{Binding FunctionName, FallbackValue=Functionname}" />
<Button Grid.Row="1" Content="{Binding DisplayValue, FallbackValue=0.5dB}" />
</Grid>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="{x:Type local:CustomControl2}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<ContentControl x:Name="PART_DisplayLayer" Style="{StaticResource DefaultTemplate}" />
<Grid x:Name="PART_ControlsLayer" Grid.Row="1">
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Button Grid.Row="0" Content="Depp" />
<Button Grid.Row="1" Content="{Binding DisplayValue, FallbackValue=1.0dB}" />
</Grid>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
CustomControl2.cs as Derived-Class
using System.Windows;
namespace WpfCustomControlLibrary1
{
public class CustomControl2 : CustomControl1
{
static CustomControl2()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomControl2), new FrameworkPropertyMetadata(typeof(CustomControl2)));
}
public CustomControl2()
{
DataContext = this;
}
}
}
MainWindow still the same.
This is working since nothing of content is static.