Resource

Android 資源分為以下幾種：

Animation Resources

Define pre-determined animations. Tween animations are saved in res/anim/ and accessed from the R.anim class. Frame animations are saved in res/drawable/ and accessed from the R.drawable class.

Color State List Resource

Define a color resources that changes based on the View state. Saved in res/color/ and accessed from the R.color class.

Drawable Resources

Define various graphics with bitmaps or XML. Saved in res/drawable/ and accessed from the R.drawable class.

Layout Resource

Define the layout for your application UI. Saved in res/layout/ and accessed from the R.layout class.

Menu Resource

Define the contents of your application menus. Saved in res/menu/ and accessed from the R.menu class.

String Resources

Define strings, string arrays, and plurals (and include string formatting and styling). Saved in res/values/ and accessed from the R.string, R.array, and R.plurals classes.

Style Resource

Define the look and format for UI elements. Saved in res/values/ and accessed from the R.style class.

More Resource Types

Tools Attributes

Tools Attributes 也是一個命名空間，不過在編譯打包過程中，並不會把 tools 命名空間的部分打包進去；它的作用主要就是在協助開發過程。

tools:ignore

tools:targetApi

tools:locale

tools:context

這個屬性通常是設定在 Layout XML 的根元素，它的值會是 Activity。設定了之後，IDE 會把此 Layout 跟設定的 Activity 建立關聯。這時，因 Activity 的主題都是在 AndroidManifest.xml 定義，IDE 有了關聯後，Layout Editor 就會自動設定成該 Activity 的 Theme。

它的值跟 AndroidManifest.xml 一樣可以用 . 代表 package。

Example:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              tools:context=".MainActivity">
</LinearLayout>

tools:layout

tools:listitem / listheader / listfooter

Designtime Attributes

String

如果遇到兩個以上的 % 可能需要用 \u0025 再用 utf8 解碼才行

http://stackoverflow.com/questions/9386411/escape-multiple-characters-in-android