July 2014
Intermediate to advanced
248 pages
5h 19m
Chinese
Content preview from Android Developer Tools深入精要
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開發者選項選單
|
121
[Page-126]
開發者選項選單
Android 4.0
包含一個舊有翻新的開發者工具，內含一些非常有趣的功能；要使用該工
具，先打開手機裡的「
Settings
（設定）」
app
，再點選「
Developer Options
（開發者選
項）」。此 程式（ 圖
8-10
）包含許多開發者可以用來理解
UI
以及
app
效能的進階選項：
嚴格模式已啟用（
Strict mode enabled
）
當
app
在
UI
執行緒執行過久的操作時會閃爍整個螢幕。這在驗證
UI
卡住以及調
查
UI
沒有回應的次數時很有用。行動裝置的使用者能察覺到非常細微的延遲，所
以你需要盡可能地減少它。這選項可以更簡單地找到執行過久的處理程序，而可
以將它們從
UI
執行緒移到背景執行緒（而不會造成
app
卡住）。
指標位置（
Pointer location
）
圖
8-11
顯示你可以強調螢幕上的特定位置。你可以透過手指或滑鼠移動到螢幕上
的任意地方來得知該處的確切位置座標；這在你需要辨識出較難點擊的項目，或
是確認最佳的間隔距離，或是要提升觸控的互動性時會很有幫助。你可以根據像
素的測量來得知
UI
上確切的位置座標，這在將
UI
元件對應到一個非常精確的位
置時會很有用（在某些程式裡較嚴格，包括遊戲或其他具高度圖形化需求的
app
）。
顯示螢幕更新（
Show screen updates
）
當畫面上的不同元件被重繪時，這功能會閃爍並強調其不同的區域；這在打算提
升效能時會很有幫助。你可以識別出多數的螢幕重繪，為了試著減少重繪，透過
選擇性地重繪某些元件，而不是重繪整個畫面。 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.