Advanced Expression Blend for Developers: Integrating MVVM and Designability

Just a quick summary:

• The presenter, Pete Brown, went over MVVM real fast. The gist is Model, View, ViewModel. But inreality it is more like View > ViewModel > Model. Where View is the GUI, and Model is the data source, and ViewModel is the stuff in between


• The concept is to seperate the User interface from the intermdiate level and also to seperate the intermediate level from the back end.


• Althopugh he covered many points, the one that I really took away from it was the concept of design time data sources. This is used for development purposes during the design time.


• for example: This shows how one data source can be used at design time and another at run time.


• Then you would use the IsDesignTimeCreateable = True in your binding statement in order to get it to work


• Also, once you have you design time data source, you can drag and drop in Blend and it will create your binding statements for you. This will be useful when there are a lot of binding statements to write.


• You wlould use the DesignerProperties.IsInDesignTool to figure out which datasource should be returned. If the same interface is used for both Deisgn and Run time you can return the same data tyep in your services.


• He also went over Behaviors and Commands in Blend but I will need some time digest that material. Basically a Command is like binding for an action.