Changing Visual State in Custom Control

Call VisualStateManager.GoToState(control, strStateName, useTransitions)
strStateName is mapped to a TemplateVisualStateAttribute of the control class.

PrintDocument

sample: http://web.archive.org/web/20101128170826/http://silverlightips.net/2010/03/27/multi-page-printing-in-silverlight/
including:
PrintDocument .PrintPage (event) .Print (method)
PrintPageEventArgs .PageVisual (UIElement) .PrintableArea (Size) .HasMorePages

Also usage of Canvas.TopProperty in SetValue

GetTemplateChild vs. FindName

http://msdn.microsoft.com/en-us/library/system.windows.controls.control.gettemplatechild(v=vs.95).aspx

http://social.msdn.microsoft.com/forums/en-US/wpf/thread/eb509920-e2c3-43d7-987b-6f67cbd544c9

OnApplyTemplate, Loaded, and LayoutUpdated

For pros and cons: http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement.loaded(v=vs.95).aspx
http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement.onapplytemplate(v=vs.95).aspx

TemplateBindings

TemplateBindings are special bindings usable only in ControlTemplates (no DataTemplates), whose binding source is the control instance on which the template is applied.

http://forums.silverlight.net/t/158826.aspx/1

Dependency Properties vs. Attached Properties

Attached Properties use an accessor style that XAML parser can use, i.e. SetPropertyName
As opposed to regular dependency properties that use regular Set/Get accessors.

For attached properties see: http://msdn.microsoft.com/en-us/library/cc265152(v=vs.95).aspx

For regular dependency property requirements see Checklist for Defining a Dependency Property
Nice sample of custom dependency object here (bottom)

Silverlight 4 Validation

This two-part series sums it up:
http://www.silverlightshow.net/items/The-validation-story-in-Silverlight-Part-1.aspx
http://www.silverlightshow.net/items/The-validation-story-in-Silverlight-Part-2.aspx

SL 3 supports ValidatesOnExceptions=True, NotifyOnValidationError=True
Throw exceptions in setters. Optionally use validation attributes on model properties: this requires Validator.ValidateProperty(value, new ValidationContext... in setter
Can use CustomValidation attribute and sdk:ValidationSummary tag

SL4 introduces IDataErrorInfo plus ValidatesOnDataErrors=True tag
and INotifyDataErrorInfo plus ValidatesOnNotifyDataErrors=True

Can customize the validation states in Blend: Default transition, Valid, InvalidUnfocused, InvalidFocused

Easing Functions - XAML Syntax

DoubleAnimation...DoubleAnimation.EasingFunction vs. DoubleAnimationUsingKeyFrames...EasingDoubleKeyFrame

Samples here

In the previous example, the easing functions are applied to a From/To/By animation. You can also apply these easing functions to Key-Frame animations using either EasingDoubleKeyFrame, EasingPointKeyFrame, or EasingColorKeyFrame 

Using VisualStateManager in Code

VisualStateManager.GoToState  http://timheuer.com/blog/archive/2008/06/04/silverlight-introduces-visual-state-manager-vsm.aspx

Attached Properties are DependencyProperties

See "Attached Properties" at http://www.wpftutorial.net/dependencyproperties.html

DoubleAnimation, DoubleAnimationUsingKeyFrames

1. DoubleAnimation - Uses a From/To direction.
2. DoubleAnimationUsingKeyFrames - This is a container for a set of key frames that will determine the value at a given set of points along a time line. We will look at this option in our next tip of the day. 

http://blogs.silverlight.net/blogs/msnow/archive/2008/12/01/silverlight-tip-of-the-day-76-animating-objects-with-doubleanimation.aspx

Control, ContentControl, ItemsControl

Differences between when inheriting and the Visual Tree/Leaf paradigm.

DependencyObject/DependencyProperty

DependencyProperty's (e.g. a Canvas' left, right) are assigned to DependencyObjects, e.g. UI elements. http://blog.hackedbrain.com/2004/12/04/understanding-dependencyobject-and-dependencyproperty/

Example usage of DependencyProperty to add second ContentPresenter to a ControlTemplate

For the uncommon cases where a settable property on a DependencyObject is not a dependency property, that property will be unable to support animation, data binding, or FrameworkElement styling.

http://msdn.microsoft.com/en-us/library/cc221408(v=vs.95).aspx

XAML Concepts

See http://msdn.microsoft.com/en-us/library/ms752059.aspx for descriptions of:

XAML Object Elements (represent WPF types)
Property Element Syntax (vs Attribute Syntax)
Markup Extensions - for setting property dynamically at runtime
Type Converters (e.g. Margin/Thickness)

ItemsPanelTemplate with Horizontal Orientation

ControlTemplate, ContentPresenter, & TemplateBinding

See example for these at bottom of http://msdn.microsoft.com/en-us/library/system.windows.controls.contentpresenter(v=vs.95).aspx

Storyboards

http://www.silverlightbuzz.com/2009/10/12/animating-with-storyboards-in-blend/

itemscontrol itemspresenter listbox

http://stackoverflow.com/questions/3723893/itemscontrol-itemspanel-and-itemspresenter-silverlight-xaml
Note, ex on itemspanel "Basically, the ItemPresenter (specified in the Template) will be replaced with whatever is specified in the ItemsPanelTemplate." -mmmmmm