[WPF] WPF 4.5 New Features

好久没有来了。看了个微软介绍WPF 4.5 新特性的视频。在这里连同自己理解的部分Memo一下，可能有些地方理解不正确，希望谅解～ 

ps. 发现自己博客里面各种技术杂项都有。。汗。。-_-b

New Features of WPF 4.5

• Conditional compile
• PCL - portable class library 
  • support for many platforms (Desktop / Silverlight / Xbox / Windows app store .etc)
• async and await
  • async fucntion has await sentances (call)
  • normal function has corresponding await function which could be called from client .
  • -> especially useful for web application
  • -> service has a function and generate 1.task 2.async operation (Through dialogue tool)

• New binding expression
  • binding to static properties
• Binding delay -> slide do not fire value change event until it's stable
Live shaping of collections -> 可以针对某一个field排序
• e.g ListCollectionView - class

 

viewObject = new ListCollectionView(AAA) // here AAA is ObservableCollection
viewObject.SortDescriptions.Add
viewObject.LiveSortingProerties.Add("Values")
viewObject.IsLiveSorting = true;

•  Virtualizing panel support for pixel scrolling
  • a large dataset to show - have to use virtualizing and use cache and cache item (page or item)
  • Listbox has properties : VirtualizingPanel.ScrollUnit(Item/Pixel) / CacheLength / CacheLengthUnit(Page)
  • Here “pixel” is new   -> 也就是拉动滚动条的时候， listbox是以pixel为单位滚动。
• Event weak references  -> 貌似可以自动release eventhandler
  • Built-in support for the weak event pattern
  • Use when listener donesn't know when to unhook event handler
  • Helps avoid memory leaks
  • Generic WeakEventManager
• Accessing collections on non-UI threads  -> 在非UI线程中也可以动态同步更新collection
  • BindingOperations.EnableCollectionSyncronization(AAA, lock) ; => AAA is ObservableCollection, lock is an object of Object class

• Others:
  • built-in ribbon and ribbon window
  • INotifyDataErrorInfo
  • ICustomTypeProvider