[UI]抽屜菜單DrawerLayout分析
本文轉載於：http://www.cnblogs.com/avenwu/a
[UI]抽屜菜單DrawerLayout分析（一）
2015-01-05 15:47 862人閱讀 評論(0) 收藏 舉報
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本文轉載於：http://www.cnblogs.com/avenwu/archive/2014/04/16/3669367.html
側拉菜單作爲常見的導航交互控件，最開始在沒有沒有android官方控件時，很多時候都是使用開源的SlidingMenu，一直沒機會分析側拉菜單的實現機理，本文將分析android.support.v4.widget.DrawerLayout的使用及實現。
Device 2014 04 16 191818
官方介紹
DrawerLayout acts as a top-level container for window content that allows for interactive “drawer” views to be pulled out from the edge of the window.
Drawer positioning and layout is controlled using the android:layout_gravity attribute on child views corresponding to which side of the view you want the drawer to emerge from: left or right. (Or start/end on platform versions that support layout direction.)
To use a DrawerLayout, position your primary content view as the first child with a width and height of match_parent. Add drawers as child views after the main content view and set the layout_gravity appropriately. Drawers commonly use match_parent for height with a fixed width.
DrawerLayout.DrawerListener can be used to monitor the state and motion of drawer views. Avoid performing expensive operations such as layout during animation as it can cause stuttering; try to perform expensive operations during the STATE_IDLE state. DrawerLayout.SimpleDrawerListener offers default/no-op implementations of each callback method.
As per the Android Design guide, any drawers positioned to the left/start should always contain content for navigating around the application, whereas any drawers positioned to the right/end should always contain actions to take on the current content. This preserves the same navigation left, actions right structure present in the Action Bar and elsewhere
DrawerLayout直譯的事抽屜佈局的意思，作爲視窗內的頂層容器，它允許用戶通過抽屜式的推拉操作，從而把視圖視窗外邊緣拉到屏幕內，如右圖：
抽屜菜單的擺放和佈局通過android:layout_gravity屬性來控制，可選值爲left、right或start、end。通過xml來佈局的話，需要把DrawerLayout作爲父容器，組界面佈局作爲其第一個子節點，抽屜佈局則緊隨其後作爲第二個子節點，這樣就做就已經把內容展示區和抽屜菜單區獨立開來，只需要分別非兩個區域設置內容即可。android提供了一些實用的監聽器，重載相關的回調方法可以在菜單的交互過程中書寫邏輯業務。下面是一個demo佈局: