"8-16" Android Learning Note 01
Last Update:2015-08-16
Source: Internet
Author: User
<span id="Label3"></p>Android Directory tree<p><p></p></p>Activity life cycle<p><p></p></p>Create an Activity<p><p><em id="__mceDel">Create an Activity in Android to write a Java class that inherits from Android.app.Activity and declare it in ANDROIDMANIFEST.XML. Here is an activity example to study the activity life cycle (see download for engineering source):</em></p></p><pre><span style="color: #008080;"><span style="color: #008080;">1</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"></span> public</span> <span style="color: #0000ff;"><span style="color: #0000ff;">class</span></span>EX01<span style="color: #0000ff;"><span style="color: #0000ff;">extends</span></span><span style="color: #000000;"><span style="color: #000000;">Activity {</span></span><span style="color: #008080;"><span style="color: #008080;">2</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">Private</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">Static</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">Final</span></span>String Log_tag = EX01.<span style="color: #0000ff;"><span style="color: #0000ff;">class</span></span><span style="color: #000000;"><span style="color: #000000;">. Getsimplename ();</span></span><span style="color: #008080;"><span style="color: #008080;">3</span></span> <span style="color: #000000;"><span style="color: #000000;">@Override</span></span><span style="color: #008080;"><span style="color: #008080;">4</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"></span> public</span> <span style="color: #0000ff;"><span style="color: #0000ff;">void</span></span><span style="color: #000000;"><span style="color: #000000;">onCreate (Bundle Savedinstancestate) {</span></span><span style="color: #008080;"><span style="color: #008080;">5</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">Super</span></span><span style="color: #000000;"><span style="color: #000000;">. OnCreate (savedinstancestate); </span></span><span style="color: #008080;"><span style="color: #008080;">6</span></span> <span style="color: #000000;"><span style="color: #000000;">Setcontentview (r.layout.main);</span></span><span style="color: #008080;"><span style="color: #008080;">7</span></span>LOG.E (log_tag, "onCreate"<span style="color: #000000;"><span style="color: #000000;">); </span></span><span style="color: #008080;"><span style="color: #008080;">8</span></span> <span style="color: #000000;"><span style="color: #000000;"> } </span></span><span style="color: #008080;"><span style="color: #008080;">9</span></span> <span style="color: #000000;"><span style="color: #000000;">@Override</span></span><span style="color: #008080;"><span style="color: #008080;">Ten</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">protected</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">void</span></span><span style="color: #000000;"><span style="color: #000000;">OnStart () {</span></span><span style="color: #008080;"><span style="color: #008080;"></span> one</span>LOG.E (log_tag, "onStart"<span style="color: #000000;"><span style="color: #000000;">); </span></span><span style="color: #008080;"><span style="color: #008080;"></span> a</span> <span style="color: #0000ff;"><span style="color: #0000ff;">Super</span></span><span style="color: #000000;"><span style="color: #000000;">. OnStart ();</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #000000;"><span style="color: #000000;"> } </span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #000000;"><span style="color: #000000;">@Override</span></span><span style="color: #008080;"><span style="color: #008080;"></span> the</span> <span style="color: #0000ff;"><span style="color: #0000ff;">protected</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">void</span></span><span style="color: #000000;"><span style="color: #000000;">onresume () {</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span>LOG.E (log_tag, "onresume"<span style="color: #000000;"><span style="color: #000000;">); </span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #0000ff;"><span style="color: #0000ff;">Super</span></span><span style="color: #000000;"><span style="color: #000000;">. Onresume ();</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #000000;"><span style="color: #000000;"> } </span></span><span style="color: #008080;"><span style="color: #008080;"></span> +</span> <span style="color: #000000;"><span style="color: #000000;">@Override</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #0000ff;"><span style="color: #0000ff;">protected</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">void</span></span><span style="color: #000000;"><span style="color: #000000;">onPause () {</span></span><span style="color: #008080;"><span style="color: #008080;"></span> +</span>LOG.E (log_tag, "onPause"<span style="color: #000000;"><span style="color: #000000;">); </span></span><span style="color: #008080;"><span style="color: #008080;"></span> a</span> <span style="color: #0000ff;"><span style="color: #0000ff;">Super</span></span><span style="color: #000000;"><span style="color: #000000;">. OnPause ();</span></span><span style="color: #008080;"><span style="color: #008080;"></span> at</span> <span style="color: #000000;"><span style="color: #000000;"> } </span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #000000;"><span style="color: #000000;">@Override</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #0000ff;"><span style="color: #0000ff;">protected</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">void</span></span><span style="color: #000000;"><span style="color: #000000;">onStop () {</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span>LOG.E (log_tag, "onStop"<span style="color: #000000;"><span style="color: #000000;">); </span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #0000ff;"><span style="color: #0000ff;">Super</span></span><span style="color: #000000;"><span style="color: #000000;">. OnStop ();</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #000000;"><span style="color: #000000;"> } </span></span><span style="color: #008080;"><span style="color: #008080;"></span> in</span> <span style="color: #000000;"><span style="color: #000000;">@Override</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #0000ff;"><span style="color: #0000ff;">protected</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">void</span></span><span style="color: #000000;"><span style="color: #000000;">OnDestroy () {</span></span><span style="color: #008080;"><span style="color: #008080;"></span> to</span>LOG.E (log_tag, "ondestroy"<span style="color: #000000;"><span style="color: #000000;">); </span></span><span style="color: #008080;"><span style="color: #008080;"></span> +</span> <span style="color: #0000ff;"><span style="color: #0000ff;">Super</span></span><span style="color: #000000;"><span style="color: #000000;">. OnDestroy ();</span></span><span style="color: #008080;"><span style="color: #008080;"></span> -</span> <span style="color: #000000;"><span style="color: #000000;"> } </span></span><span style="color: #008080;"><span style="color: #008080;"></span> the</span>}</pre><p><p>Androidmanifest.xml in the <activity> node description activity, after installing the APK file, the system according to the instructions here to find read activity, in this example, the instructions are as Follows:</p></p><pre><span style="color: #008080;"><span style="color: #008080;">1</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">Activity</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:name</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">=". EX01 "</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:label</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "@string/app_name"</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span> <span style="color: #008080;"><span style="color: #008080;">2</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">Intent-filter</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span> <span style="color: #008080;"><span style="color: #008080;">3</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">Action</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:name</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "android.intent.action.MAIN"</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">/></span></span> <span style="color: #008080;"><span style="color: #008080;">4</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">category</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:name</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "android.intent.category.LAUNCHER"</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">/></span></span> <span style="color: #008080;"><span style="color: #008080;">5</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"></</span></span><span style="color: #800000;"><span style="color: #800000;">Intent-filter</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span> <span style="color: #008080;"><span style="color: #008080;">6</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"></</span></span><span style="color: #800000;"><span style="color: #800000;">Activity</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span></pre><p><p>SOURCE address: IBM Technical documentation: <span style="background-color: #ff0000;"> <span style="background-color: #ff0000;"> <em id="__mceDel" style="line-height: 1.5;">A detailed description of Android's Activity components</em></span></span></p></p><p><p>"8-16" Android Learning Note 01</p></p></span>
