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详细说明：Android类库介绍.pdf`Actirity
starts
oncreate(
User navigate
back to the
actvty
nsta
arto
onStar:o
Process is
killed
reSume
Activ ty Is
runin
The act/w’y
ng
comes to the
「 Anothe actvity comes
I in front of the activiry
her applications
cornes fa ihe
rHeed merry
onP
Foreground
(The activity is n longer visible
unstop
deStroy!
lut down
startActivity (Intent intent);
start Activity ForResult(Intent intent, int requestCodey
onActivityResult(int requestCode, int resultCode, Intent intent);
setResult(int result code
resultCode RESULT CANCELED, RESULT_OK, or any custom values starting at
RESULT- FIRST_USER. If a child activity fails for any reason(such as crashing), the parent
activity will receive a result with the code resUjt_canceled
Saving Persistent state
Activity通常需憂处理两种类型的的持续状态( persistent state):共享文档类型数据(典型的
是使用 Content Provider存储在 SQLite数据厍中)和内部状态(如月户徧好, User perferences)
android app. Activity Group extends Activty
Direct Subclass: TabActivity
A screen that contains and runs multiple embedded activities
Android app. ActivityManager extends java. lang Object
Interact with the overall activities lunning in the system
这个类包含了许多内部类。
直接子类: Contextmenu, Submenu
Menu. FIRST
First value for group and item identifier integers
MenuItem add(int titleres );
Menuitem add(int groupld, int itemId, int order, CharSequence title)
MenuItem add(int groupld, int itemId, int order, int title Res);
Menultem add( CharSequence title)
public interface android view Menuitem
char getAlphabeticShortcuto
Int getGroupld(;
Drawable getleono
int getItemldo
int getorder
SubMenu getsubMenuo
Char Sequence getTitle(:
MenuItem
setOnMenultemClickListener(Menultem OnMenulteClickListener menultemClickListener
public boolean android app. Activity. onOptionsltem Selected(MenuItem item
public boolean android app. Activity. on ContextitemSelected(Menultem item
Android资源系统
一些术语
asset
Resource table
Resource
Resource identifier
Primitive resource:所有原始资源均可用一个简单的字符串表示,包括整数、颜色、字符串
和对其它资源的引用等。复杂的資源,比如位图、ⅹML文件等,被存储为个元素字符串
资源,它的值是潜在资源的路径,这个潜在资源持有实际数据。
Bag resource:
系统预留资源
android.r*sals
字符串资源
hello
there,
you/i>
ActivitvClear
resources>
/res/values/strings. xml
String back= getResources(), getString(R string. back). to String
back=get String(R string back).to(; // synonym
颜色资源
/res/values/colors. xml
#80ff0000
+OH
resources>
校式:"gb","#argb,"# rrggbb",or"# aarrggbb"
The alpha channel is Oxff (or0 xf) for opaque(不透明的)and0 for transparent(透明的)
translucent, Semitransparent:半透明的
int red= getResourcesO, get Color(R- color opaque_red)
Drawable资源
res/drawable/my_badge.pny
public void on Start
requestScreen Features (FEATURE_ BADGE_ IMAGE
super. onStarto
setBadgeResource(R drawable. my_badge)
For drawables that are a single solid colof, you can also define them in a resource file very much
like colors shown previously. The only difference is that here we use the tag to create
a drawable resource
#ffff0000
#80ff0000
#0000ff#ofO
android: drawable/theme_background
/resources>
主题属性引用
另一种資源值允许你引用当前主题的属性值,这种类型的属性引用只能用于 style资源和
XML文件中的属性。它允许你根据当前主题的变化来定制U元素的外观,以免提供更多的
具体值
android; textColor=?android: textDisabledColor
样式资源( Style resource)
一个样式资源是一组描述若干相关属性的name/ value对。这类资源有两个主要用途:定义
全局视觉主题和描述一组视觉属性(这些视觉属性用于布局资源中的一个类)。与字符串资
源一样,样式也是通过一个XML资源文件定义。
/res/values/styles.xml
