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Wpf textbox validation controltemplate trigger on text value

I have a textbox:
<TextBox Grid.Row="3"
Grid.Column="1"
Width="200"
TextWrapping="Wrap"
VerticalAlignment="Top"
Margin="5,10,-10,2"
Style="{StaticResource TextBoxValueStyle}"
Validation.ErrorTemplate="{StaticResource ValidationControlTemplate}">
<TextBox.Text>
<MultiBinding StringFormat=" {0} {1}">
<Binding Path="Id" ValidatesOnNotifyDataErrors="True" NotifyOnValidationError="True"/>
<Binding Path="Name" />
</MultiBinding>
</TextBox.Text>
</TextBox>
And here is my controltemplate:
<ControlTemplate x:Key="ValidationControlTemplate">
<DockPanel Visibility="{Binding ElementName=Placeholder, Path=Visibility}">
<Image x:Name="Image"
DockPanel.Dock="Right"
VerticalAlignment="Center"
Margin="0,-2"
Style="{StaticResource InformationImageStyle}">
<Image.ToolTip>
<ItemsControl ItemsSource="{Binding}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding ErrorContent}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Image.ToolTip>
</Image>
<AdornedElementPlaceholder Name="Placeholder" VerticalAlignment="Center"/>
</DockPanel>
<ControlTemplate.Triggers>
<Trigger Property="TextBox.Text" Value="">
<Setter Property="DockPanel.Dock" TargetName="Image" Value="Left"/>
<Setter Property="Margin" TargetName="Image" Value="-20,-2"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
My issue is that when the textbox has a value (and has error)it is NOT taking the original values (DockPanel.Dock=Right and Margin=0,-2)
I am always starting with text empty. The image is always showing to the left, on error.
What am I missing?

Put a Grid around the <AdornedElementPlaceholder /> element and replace the Trigger with a DataTrigger that binds to the adorned TextBox element:
<ControlTemplate x:Key="ValidationControlTemplate">
<DockPanel Visibility="{Binding ElementName=Placeholder, Path=Visibility}">
<Image x:Name="Image"
DockPanel.Dock="Right"
VerticalAlignment="Center"
Margin="0,-2"
Style="{StaticResource InformationImageStyle}">
<Image.ToolTip>
<ItemsControl ItemsSource="{Binding}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding ErrorContent}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Image.ToolTip>
</Image>
<Grid>
<AdornedElementPlaceholder Name="Placeholder" VerticalAlignment="Center"/>
</Grid>
</DockPanel>
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding AdornedElement.Text.Length, ElementName=Placeholder}" Value="0">
<Setter Property="DockPanel.Dock" TargetName="Image" Value="Left"/>
<Setter Property="Margin" TargetName="Image" Value="-20,-2"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>

WPF Changing ListBox background color, enabled and disabled

I'm searching how to change the background color of my WPF Listbox, nothing worked... I don't want to change the background of the Item Template, but of the ListBox himself.
I tried the differents solutions answered here Answers
Here is my Listbox :
<ListBox Name="myListBox" ScrollViewer.VerticalScrollBarVisibility="Visible" SelectionChanged="myListBox_SelectionChanged" Background="#FFC3DDF7" Margin="0,0,0,10">
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Style.Triggers>
<DataTrigger Binding="{Binding Value.IsOk}" Value="True">
<Setter Property="Background" Value="Green"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<StackPanel Width="200">
<TextBlock FontSize="10" FontWeight="Bold" VerticalAlignment="Center" Text="{Binding Path=Key}" />
<TextBlock FontSize="10" VerticalAlignment="Center" TextWrapping="Wrap">
<TextBlock.Text>
<MultiBinding StringFormat="{}{0} {1} {2}">
<Binding Path="Value.TextA" />
<Binding Path="Value.TextB" />
<Binding Path="Value.TextC" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Maybe the item template is on the foreground ?
Tried these codes :
<ListBox.Style>
<Style TargetType="{x:Type ListBox}">
<Style.Resources>
<SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Blue"/>
</Style.Resources>
</Style>
and
<ListBox>
<ListBox.Style>
<Style TargetType="{x:Type ListBox}">
<Style.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Background" Value="Blue" />
</Trigger>
</Style.Triggers>
</Style>
</ListBox.Style>
</ListBox>
Not working. The down right corner, between the two scrollbars, became blue... But that's all !

The reason why your linked answer does not work is because you have the background of the listbox set to #FFC3DDF7 on the element itself. If you wish to change the initial background color of your listbox this would need to be moved into the style. If you do not move this then the rule for "closest" defined value would be the one on the element itself and the style can't override this.
<ListBox Name="myListBox" ScrollViewer.VerticalScrollBarVisibility="Visible" SelectionChanged="myListBox_SelectionChanged" Margin="0,0,0,10">
<ListBox.Style>
<Style TargetType="{x:Type ListBox}">
<Setter Property="Background" Value="#FFC3DDF7"/>
<Style.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Foreground" Value="LightGray" />
<Setter Property="Background" Value="LightGray" />
</Trigger>
</Style.Triggers>
</Style>
</ListBox.Style>
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Style.Triggers>
<DataTrigger Binding="{Binding Value.IsOk}" Value="True">
<Setter Property="Background" Value="Green"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<StackPanel Width="200">
<TextBlock FontSize="10" FontWeight="Bold" VerticalAlignment="Center" Text="{Binding Path=Key}" />
<TextBlock FontSize="10" VerticalAlignment="Center" TextWrapping="Wrap">
<TextBlock.Text>
<MultiBinding StringFormat="{}{0} {1} {2}">
<Binding Path="Value.TextA" />
<Binding Path="Value.TextB" />
<Binding Path="Value.TextC" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>

As Anthony pointed out, your style trigger will never set the Background of your ListBox because you have set a local value. It's called "Dependency Property Precedence". Take a look at this link: https://learn.microsoft.com/en-us/dotnet/framework/wpf/advanced/dependency-property-value-precedence.
"Local" values have higher precedence over "style trigger" values. However, "style trigger" values have higher precedence over "style setter" values. This means that if you want to have an initial value for the property and change it based on a trigger, just set it in the style initially, instead of setting it locally like your code does.

First off all - this msdn link ListBox Styles and Templates will help you the most. You can check this way - what applies where in a ListBox and a ListBoxItem.
If you check the Style of the ListBoxItem you will see that the ContentPresenter gets no Foreground applied.
<Style TargetType="ListBoxItem">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBoxItem">
<Grid Background="{TemplateBinding Background}">
<ContentPresenter x:Name="contentPresenter"
Content="{TemplateBinding Content}"
ContentTemplate="{TemplateBinding ContentTemplate}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
Margin="{TemplateBinding Padding}"/><!-- No foreground gets applied. -->
<Rectangle x:Name="FocusVisualElement" Stroke="#FF6DBDD1" StrokeThickness="1" Visibility="Collapsed" RadiusX="1" RadiusY="1" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Anyway here is your solution:
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal"
Width="200">
<TextBlock VerticalAlignment="Center"
FontSize="10"
TextWrapping="Wrap">
<Run FontWeight="Bold" Text="{Binding Path=Key}" />
<LineBreak />
<Run>
<Run.Text>
<MultiBinding StringFormat="{}{0} {1} {2}">
<Binding Path="Value.TextA" />
<Binding Path="Value.TextB" />
<Binding Path="Value.TextC" />
</MultiBinding>
</Run.Text>
</Run>
<TextBlock.Style>
<Style TargetType="{x:Type TextBlock}">
<Style.Triggers>
<DataTrigger Binding="{Binding IsOk}" Value="True" >
<Setter Property="Foreground" Value="Green"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
The TextBlock now listens to isOk and will applys the Foreground.

Style TreeviewItem layout (MVVM)

I have a TreeView to which I bind a ObservableCollection where TreeView inherits TreeViewItem.
I want to style the header of the tree view to have a image in front of each header. I setted the header to the ItemContainerStyle but it did not chnage its layout. However it works for the ContextMenu.
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="ToolTip" Value="{Binding ID, Mode=TwoWay}"/>
<Setter Property="Header">
<Setter.Value>
<StackPanel Orientation="Horizontal">
<Image Source="Images/Icons/Plus-48.png" Height="10" Width="10" />
<TextBlock Text="{Binding MachinePartName}" Margin="0,0,4,0" />
</StackPanel>
</Setter.Value>
</Setter>
<Setter Property="ContextMenu">
<Setter.Value>
<ContextMenu>
<MenuItem Header="Add" Command="{Binding AddMachinePart_Command}"/>
</ContextMenu>
</Setter.Value>
</Setter>
</Style>
</TreeView.ItemContainerStyle>

You need to use HeaderTemplate instead:
<Setter Property="Header"
Value="{Binding }" />
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Image Source="Images/Icons/Plus-48.png"
Height="10"
Width="10" />
<TextBlock Text="{Binding MachinePartName}"
Margin="0,0,4,0" />
</StackPanel>
</DataTemplate>
</Setter.Value>
</Setter>
Don't forget to bind Header property.

DataBinding ListView creating components if a certain condition is met

I am working on a C# WPF project and I have a list view which uses data binding and a collection view.
Below is how my ListView is currently populated.
<ListView HorizontalAlignment="Left" Margin="547,12,0,41" Name="lstCallLogInformation" Width="320">
<ListView.Style>
<Style TargetType="ListView">
<Style.Triggers>
<Trigger Property="HasItems" Value="False">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListView">
<TextBlock Text="No items in your devices call log" FontWeight="Bold" HorizontalAlignment="Center" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
</ListView.Style>
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Expander IsExpanded="True">
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock FontWeight="Bold" Foreground="Gray" Text="{Binding Name}" VerticalAlignment="Bottom" />
</StackPanel>
</Expander.Header>
<ItemsPresenter />
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</ListView.GroupStyle>
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="Control.HorizontalContentAlignment" Value="Stretch" />
</Style>
</ListView.ItemContainerStyle>
<ListView.ItemTemplate>
<DataTemplate>
<DockPanel Style="{StaticResource onmouseover}">
<StackPanel HorizontalAlignment="Stretch" Orientation="Horizontal" Tag="{Binding logID}">
<Image Height="30" Source="{Binding base64ImageString, Converter={StaticResource ImageConverter}}" Width="30" />
<StackPanel Margin="10" Orientation="Vertical">
<TextBlock FontWeight="Bold" Text="{Binding contactNameOrPhoneNumber}" />
<StackPanel HorizontalAlignment="Stretch" Orientation="Horizontal">
<TextBlock HorizontalAlignment="Left" Text="{Binding dateString}" />
<TextBlock Margin="15, 0, 0, 0" Text="Duration: " />
<TextBlock HorizontalAlignment="Right" Text="{Binding humanReadableCallDuration}" />
</StackPanel>
</StackPanel>
<StackPanel Orientation="Vertical">
<Button Background="Transparent" BorderThickness="0" BorderBrush="Transparent" Tag="{Binding logID}" Name="btnAddAsContact" Click="btnAddAsContact_Click">
<Image Width="15" Height="15" Source="/BoardiesSMSServer;component/images/add.png" Tag="{Binding logID}" />
</Button>
<Button Background="Transparent" BorderThickness="0" BorderBrush="Transparent" Tag="{Binding logID}" Name="btnDeleteContactFromLog" Click="btnDeleteContactFromLog_Click">
<Image Width="15" Height="15" Source="/BoardiesSMSServer;component/images/delete.png" Margin="0,0,0,5" Tag="{Binding logID}" />
</Button>
</StackPanel>
</StackPanel>
</DockPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Within my DockPanel within the DataTemplate I have a StackPanel which contains various TextBlocks from the array that is passed into the binding.
In one of the StackPanels you will see you will see a TextBlock that binds to the element of contactNameOrPhoneNumber.
What I want to be able to do is if another value from the binding is null then I add a TextBlock for the contactNameOrPhoneNumber` element and alongside it have another TextBlock which contains another element of number``, if the other binding value is not null then this extra textblock of number is not added.
So in simple terms, what I want to be able to do is within the DataTemplate have a conditional if statement of if binding value == null add textblock to stackpanel else don't add textblock.

You can do that with Style + Triggers something like this:
<TextBlock>
<TextBlock.Style>
<Style TargetType="TextBlock">
<Style.Triggers>
<DataTrigger Binding="{Binding PropertyName}" Value="{x:Null}">
<Setter Property="Visibility" Value="Collapsed"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
Also you can create IValueConverter say ObjectToVisibilityConverter which will take input your property and if property is null return Visibility.Collapsed else return Visibility.Visible.
You can then bind property with Visibility value of TextBlock via Converter.
<TextBlock Visibility="{Binding PropertyName,
Converter={StaticResource ObjectToVisibilityConverter}}"/>

bind the date of the DatePicker to ConverterParameter

I'm trying to mark Names in a ComboBox based on a Date from a DatePicker using a converter class.
My current problem is I don't know how to bind the date of the DatePicker to the "ConverterParameter". Any suggestions?
(probably more errors in my code but i'm stuck at this point)
<Page.Resources>
<Style TargetType="ComboBoxItem" x:Key="combostyle">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ComboBoxItem">
<ControlTemplate.Resources>
<src:ColorFromMagazijnierIdConverter x:Key="conv" />
</ControlTemplate.Resources>
<Grid ToolTip="{Binding Converter={StaticResource conv}, ConverterParameter={ BIND THIS TO THE DATEPICKER DATE }, Mode=OneWay}">
<Rectangle x:Name="MarkedItemBackground" IsHitTestVisible="False" Fill="#80FF0000" />
<!--...-->
</Grid>
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding Converter={StaticResource conv}}"
Value="{x:Null}">
<Setter TargetName="MarkedItemBackground"
Property="Visibility" Value="Hidden" />
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Page.Resources>
<Grid Margin="10,10,10,0" Name="rootGrid">
<ComboBox Name="collectMagazijnierComboBox"
DisplayMemberPath="User.Name"
ItemContainerStyle="{DynamicResource ResourceKey=combostyle}"/>
<DatePicker Name="collectDatePicker" />
</Grid>

The ConverterParameter property cannot be the target of a binding. Only a DependencyProperty of a DependencyObject can be the target of a binding.
You'll need to use a MultiBinding:
<Grid>
<Grid.ToolTip>
<MultiBinding Converter="{StaticResource conv}" Mode="OneWay">
<Binding /> <!-- this mimics your current binding to the datacontext itself -->
<Binding ElementName="collectDatePicker" Path="SelectedDate" />
</MultiBinding>
</Grid.ToolTip>
<Rectangle x:Name="MarkedItemBackground" IsHitTestVisible="False" Fill="#80FF0000" />
<!--...-->
</Grid>
You'll then need to rewrite your ColorFromMagazijnierIdConverter converter to implement the IMultiValueConverter interface instead, in which you can access both values.
Although, I'm not 100% sure whether you can reference the collectDatePicker by ElementName from within the style resource like that. But sure you can play around with it!