StringFormat in WPF XAML

http://www.wpf-tutorial.com/data-binding/the-stringformat-property/

Dependency Property Value Precedence

When you get the value of a dependency property, you are potentially obtaining a value that was set on that property through any one of the other property-based inputs that participate in the WPF property system. Dependency property value precedence exists so that a variety of scenarios for how properties obtain their values can interact in a predictable way.
Consider the following example. The example includes a style that applies to all buttons and their Background properties, but then also specifies one button with a locally set Background value.

Note
The SDK documentation uses the terms "local value" or "locally set value" occasionally when discussing dependency properties. A locally set value is a property value that is set directly on an object instance in code, or as an attribute on an element in XAML.

In principle, for the first button, the property is set twice, but only one value applies: the value with the highest precedence. A locally set value has the highest precedence (except for a running animation, but no animation applies in this example) and thus the locally set value is used instead of the style setter value for the background on the first button. The second button has no local value (and no other value with higher precedence than a style setter) and thus the background in that button comes from the style setter.

 

 

XAML

<StackPanel>
  <StackPanel.Resources>
    <Style x:Key="{x:Type Button}" TargetType="{x:Type Button}">
     <Setter Property="Background" Value="Red"/>
    </Style>
  </StackPanel.Resources>
  <Button Background="Green">I am NOT red!</Button>
  <Button>I am styled red</Button>
</StackPanel>

View Injection

http://www.wpftutorial.net/ReferenceArchitecture.html

Prism Event Aggregator

http://msdn.microsoft.com/en-us/library/ff921122.aspx

Prism Interactivity / Notification

http://msdn.microsoft.com/en-us/library/ff921081%28v=pandp.40%29.aspx

MVVM

http://msdn.microsoft.com/en-us/library/gg405484%28v=pandp.40%29.aspx

DependencyProperties

• Change notification
  Dependency properties have a built-in change notification mechanism. By registering a callback in the property metadata you get notified, when the value of the property has been changed. This is also used by the databinding. 
•  Value inheritance
  When you access a dependency property the value is resolved by using a value resolution strategy. If no local value is set, the dependency property navigates up the logical tree until it finds a value. When you set the FontSize on the root element it applies to all textblocks below except you override the value.
  
• Reduced memory footprint
  It's a huge dissipation to store a field for each property when you think that over 90% of the properties of a UI control typically stay at its initial values. Dependency properties solve these problems by only store modified properties in the instance. The default values are stored once within the dependency property.
   

Here is a very good article for DependancyProperty.

http://wpftutorial.net/DependencyProperties.html

http://wpftutorial.net/DependencyProperties.html

DependencyProperty.Register

DependencyProperty.RegisterReadOnly

DependencyProperty.RegisterAttched