Android Widget Learning Summary
Last Update:2015-06-15
Source: Internet
Author: User
<span id="Label3"></p><p><p>1.Widget Design steps need to modify three xml, one class:</p></p><p><p>1) the first XML is the layout XML file (for example: main.xml), which is the Widget. In general, If you use this widget to display time, just declare a textview in this layout xml.</p></p><p><p>2) the second XML is widget_provider.xml, which is used primarily to declare a appwidget. Layout is the designation of the Main.xml Above.</p></p><p><p>3) the third XML is androidmanifest.xml, registering Broadcastreceiver Information.</p></p><p><p>4) the last class is used to do some business logic operations. Let it inherit the class Appwidgetprovider. There are many methods in appwidgetprovider, in general we just overwrite the OnUpdate (context,appwidgetmanager,int[]) method.</p></p><p><p>2. Code CASE</p></p><p><p>1) Main.xml</p></p><pre><span style="color: #0000ff;"><span style="color: #0000ff;"><?</span></span><span style="color: #ff00ff;"><span style="color: #ff00ff;">XML version= "1.0" encoding= "utf-8"</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">?></span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">LinearLayout</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">xmlns:android</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "http://schemas.android.com/apk/res/android"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">android:orientation</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "vertical"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:layout_width</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "fill_parent"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:layout_height</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "fill_parent"</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">TextView</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:id</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "@+id/tvcurrtime"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:layout_width</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "wrap_content"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:layout_height</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "wrap_content"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:text</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "@string/hello"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:textcolor</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "@color/black"</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">/></span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"></</span></span><span style="color: #800000;"><span style="color: #800000;">LinearLayout</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span></pre><p><p>2) Hello_widget_provider.xml</p></p><pre><pre><span style="color: #0000ff;"><?</span> <span style="color: #ff00ff;">XML version= "1.0" encoding= "utf-8"</span> <span style="color: #0000ff;">?></span> <span style="color: #0000ff;"><</span> <span style="color: #800000;"></span> <span style="color: #ff0000;">xmlns:android</span><span style="color: #0000ff;">= "http://schemas.android.com/apk/res/android"</span> <span style="color: #ff0000;"> android:minwidth</span> <span style="color: #0000ff;">= "146dip"</span> <span style="color: #ff0000;">Android:minheight</span> <span style="color: #0000ff;">= "72dip"</span> <span style="color: #ff0000;">Android:initiallayout</span> <span style="color: #0000ff;">= "@layout/main"</span> <span style="color: #0000ff;">></span> <span style="color: #0000ff;"></</span> <span style="color: #800000;">Appwidget-provider</span> <span style="color: #0000ff;">></span></pre></pre><p><p>3) Androidmanifest.xml</p></p><pre><span style="color: #0000ff;"><span style="color: #0000ff;"><?</span></span><span style="color: #ff00ff;"><span style="color: #ff00ff;">XML version= "1.0" encoding= "utf-8"</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">?></span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">Manifest</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">xmlns:android</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "http://schemas.android.com/apk/res/android"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;"></span> package</span><span style="color: #0000ff;"><span style="color: #0000ff;">= "com.woody.testWidget"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:versioncode</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "1"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:versionname</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "1.0"</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">Application</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:icon</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "@drawable/icon"</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: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">receiver</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:name</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">=". Hellowidgetprovider "</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: #008000;"><span style="color: #008000;"><!--</span></span><span style="color: #008000;"><span style="color: #008000;">Hellowidgetprovider for that class (business Processing)</span></span><span style="color: #008000;"><span style="color: #008000;"></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: #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.appwidget.action.APPWIDGET_UPDATE"</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">/></span></span> <span style="color: #008000;"><span style="color: #008000;"><!--</span></span><span style="color: #008000;"><span style="color: #008000;">of the specified</span></span><span style="color: #008000;"><span style="color: #008000;"></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: #0000ff;"><span style="color: #0000ff;"><</span></span><span style="color: #800000;"><span style="color: #800000;">Meta-data</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:name</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "android.appwidget.provider"</span></span><span style="color: #ff0000;"><span style="color: #ff0000;">Android:resource</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">= "@xml/hello_widget_provider"</span></span> <span style="color: #0000ff;"><span style="color: #0000ff;">/></span></span> <span style="color: #008000;"><span style="color: #008000;"><!--</span></span><span style="color: #008000;"><span style="color: #008000;">for the widget specified above</span></span><span style="color: #008000;"><span style="color: #008000;"></span> -</span> <span style="color: #0000ff;"><span style="color: #0000ff;"></</span></span><span style="color: #800000;"><span style="color: #800000;">receiver</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"></</span></span><span style="color: #800000;"><span style="color: #800000;">Application</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span> <span style="color: #0000ff;"><span style="color: #0000ff;"></</span></span><span style="color: #800000;"><span style="color: #800000;">Manifest</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">></span></span></pre><p><p>4) Hellowidgetprovider.java</p></p><pre><span style="color: #0000ff;"><span style="color: #0000ff;"></span> public</span> <span style="color: #0000ff;"><span style="color: #0000ff;">class</span></span>Hellowidgetprovider<span style="color: #0000ff;"><span style="color: #0000ff;">extends</span></span><span style="color: #000000;"><span style="color: #000000;">Appwidgetprovider {</span></span><span style="color: #008000;"><span style="color: #008000;">/**</span></span><span style="color: #008000;">Called when the activity is first <span style="color: #008000;">Created.</span></span><span style="color: #008000;"><span style="color: #008000;">*/</span></span><span style="color: #000000;"><span style="color: #000000;">@Override</span></span><span style="color: #0000ff;"><span style="color: #0000ff;"></span> public</span> <span style="color: #0000ff;"><span style="color: #0000ff;">void</span></span>OnUpdate (context context, Appwidgetmanager appwidgetmanager,<span style="color: #0000ff;"><span style="color: #0000ff;">int</span></span><span style="color: #000000;"><span style="color: #000000;">[] Appwidgetids) {timer Timer</span></span>=<span style="color: #0000ff;"><span style="color: #0000ff;">New</span></span><span style="color: #000000;"><span style="color: #000000;">Timer (); Timer.scheduleatfixedrate (</span></span><span style="color: #0000ff;"><span style="color: #0000ff;">New</span></span>MyTime (context, appwidgetmanager), 1, 1000<span style="color: #000000;"><span style="color: #000000;">); }</span></span><span style="color: #0000ff;"><span style="color: #0000ff;"></span> public</span> <span style="color: #0000ff;"><span style="color: #0000ff;">class</span></span>MyTime<span style="color: #0000ff;"><span style="color: #0000ff;">extends</span></span><span style="color: #000000;"><span style="color: #000000;">TimerTask {remoteviews remoteviews; Appwidgetmanager appwidgetmanager; ComponentName thiswidget; DateFormat format</span></span>=<span style="color: #000000;"><span style="color: #000000;">simpledateformat.gettimeinstance (simpledateformat.medium, Locale.getdefault ()); </span></span><span style="color: #0000ff;"><span style="color: #0000ff;"></span> public</span><span style="color: #000000;"><span style="color: #000000;">MyTime (context context, appwidgetmanager appwidgetmanager) {</span></span><span style="color: #0000ff;"><span style="color: #0000ff;"></span> this</span>. Appwidgetmanager =<span style="color: #000000;"><span style="color: #000000;">appwidgetmanager; Remoteviews</span></span>=<span style="color: #0000ff;"><span style="color: #0000ff;">New</span></span><span style="color: #000000;"><span style="color: #000000;">remoteviews (context.getpackagename (), r.layout.main); Thiswidget</span></span>=<span style="color: #0000ff;"><span style="color: #0000ff;">New</span></span>ComponentName (context, Hellowidgetprovider.<span style="color: #0000ff;"><span style="color: #0000ff;">class</span></span><span style="color: #000000;"><span style="color: #000000;">); } @Override</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;">run () {remoteviews.settextviewtext (r.id.tvcurrtime,</span></span>"time =" + format.format (<span style="color: #0000ff;"><span style="color: #0000ff;">New</span></span><span style="color: #000000;"><span style="color: #000000;">Date ())); Appwidgetmanager.updateappwidget (thiswidget, remoteviews); </span>}}}</span></pre><p><p>Code explanation: RemoteView is used to describe a view that is displayed by a collapsed process, which means that the view is displayed in another process. It is inflate in the layout resource File. It also provides some simple basics that can modify the view Content.</p></p><p><p>Appwidget---remoteview,appwidgetprovider is a brocasereceiver, just accept to enable, update,disale,delete these message, The real interface is Appwidgethostview (which is implemented in launcher), which is communicated through REMOTEVIEW. By RemoteView tell launcher what you want Appwidget to look like.</p></p><p><p>Android Widget Learning Summary</p></p></span>
