Dependency property not updating usercontrol ui - wpf

Question

I have a usercontrol which has a couple of textblocks on it
<UserControl x:Class="Tester.Messenger"
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"
x:Name="myUserControl"
>
<TextBlock Text="{Binding ElementName=myUserControl,Path=Header,Mode=TwoWay}" Foreground="LightGray" FontSize="11" Margin="3,3,0,-3"/>
<TextBlock Grid.Row="1" Grid.ColumnSpan="2" Text="{Binding ElementName=myUserControl,Path=Message, Mode=TwoWay}" Foreground="White" FontSize="16" Margin="3,-5"/>
In my code behind I have two dependency properties that I'm binding the above textblocks Text property to.
public static readonly DependencyProperty HeaderProperty =
DependencyProperty.Register("HeaderProperty", typeof(string), typeof(UserControl), new PropertyMetadata("header"));
public static readonly DependencyProperty MessageProperty =
DependencyProperty.Register("MessageProperty", typeof(string), typeof(UserControl), new PropertyMetadata(null));
public string Header
{
get
{
return (string)GetValue(HeaderProperty);
}
set
{
SetValue(HeaderProperty, value);
}
}
public string Message
{
get
{
return (string)GetValue(MessageProperty);
}
set
{
SetValue(MessageProperty, value);
}
}
When I create a object of my UserControl and I change the Header and Message properties and place the control in an ItemControls items collection, then these aren't being reflected in the control. The control just displays the default values for the Header and Message.
Messenger m = new Messenger();
m.Header = "colin";
m.Message = "Download File ?";
iControl.Items.Add(m);

Answer 1

The first parameter in your call to DependencyProperty.Register is incorrect:
public static readonly DependencyProperty HeaderProperty =
DependencyProperty.Register("HeaderProperty", typeof(string), typeof(UserControl), new PropertyMetadata("header"));
should be:
public static readonly DependencyProperty HeaderProperty =
DependencyProperty.Register("Header", typeof(string), typeof(UserControl), new PropertyMetadata("header"));
The string should be the name of the property as it will appear in XAML, that is without the "Property" suffix. Same goes for your message DependencyProperty.