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widget控件

widget桌面小控件创建步骤：
1 写一个类extends AppWidgetProvider
2 在清单文件件中注册：

1         <receiver android:name=".ExampleAppWidgetProvider" >
2             <intent-filter>
3                 <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
4             </intent-filter>
5             <meta-data android:name="android.appwidget.provider"
6                        android:resource="@xml/example_appwidget_info" />
7         </receiver>

3 在res/xml创建example_appwidget_info.xml

1 <appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
2     android:minWidth="294dp"
3     android:minHeight="72dp"
4     android:updatePeriodMillis="86400000"                    更新时间最少为半个小时,可以不用写,1.6版本以上已经不再使用该属性
5     android:previewImage="@drawable/preview"                 预览图片 不用写 一般是应用程序的默认图标
6     android:initialLayout="@layout/example_appwidget"
7     android:configure="com.example.android.ExampleAppWidgetConfigure"   3.0以上的属性,3.0以下可以不使用
8     android:resizeMode="horizontal|vertical">   默认方向是水平 可以不用写该属性
9 </appwidget-provider>

4 指定布局 example_appwidget.xml

生命周期：
1 添加到桌面：
onEnabled() --> onUpdate()
2 删除
onDeleted()----> onDisabled()

如果桌面已经有一个了widget的实例存在，再次添加onUpdate()
删除之后，如果桌面上还有widget的实例存在，只会调用onDeleted().

更成时间的显示：
1 使用一个Servic来执行时间的更新
Timer TimerTask

示例代码清单文件代码：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.android.hzy.widget"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="16" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.android.hzy.widget.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver android:name=".ExampleAppWidgetProvider" >
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
            </intent-filter>

            <meta-data
                android:name="android.appwidget.provider"
                android:resource="@xml/example_appwidget_info" />
        </receiver>
        <service android:name=".MyService"></service>
    </application>

</manifest>

2.res/xml下的widget的描述信息

1 <?xml version="1.0" encoding="utf-8"?>
2 <appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android" 
3     android:minWidth="294dp"
4     android:minHeight="72dp"
5     android:initialLayout="@layout/example_appwidget"
6      >
7      
8 
9 </appwidget-provider>

3.widget布局代码

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" 
 6     android:background="@android:color/white">
 7     
 8     <TextView 
 9         android:id="@+id/tv_time"
10         android:layout_width="match_parent"
11         android:layout_height="match_parent"
12         android:text="我是widget"
13         android:textColor="#f00"
14         android:textSize="20sp"
15         />
16 
17 </LinearLayout>

4.MainActivity代码：

 1 package com.android.hzy.widget;
 2 
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 
 6 public class MainActivity extends Activity {
 7 
 8     @Override
 9     protected void onCreate(Bundle savedInstanceState) {
10         super.onCreate(savedInstanceState);
11         setContentView(R.layout.activity_main);
12     }
13 
14 }

5.继承AppWidgetProvider

 1 package com.android.hzy.widget;
 2 
 3 import java.text.SimpleDateFormat;
 4 
 5 import android.app.PendingIntent;
 6 import android.appwidget.AppWidgetManager;
 7 import android.appwidget.AppWidgetProvider;
 8 import android.content.Context;
 9 import android.content.Intent;
10 import android.util.Log;
11 import android.widget.RemoteViews;
12 
13 public class ExampleAppWidgetProvider extends AppWidgetProvider {
14 
15     /**
16      * 可用
17      */
18     @Override
19     public void onEnabled(Context context) {
20         // TODO Auto-generated method stub
21         super.onEnabled(context);
22         Log.i("i", "  onEnabled   ");
23         
24         Intent intent = new Intent(context,MyService.class);
25         context.startService(intent);
26     }
27     
28     /**
29      * 更新
30      */
31     @Override
32     public void onUpdate(Context context, AppWidgetManager appWidgetManager,
33             int[] appWidgetIds) {
34         // TODO Auto-generated method stub
35         super.onUpdate(context, appWidgetManager, appWidgetIds);
36         Log.i("i", "  onUpdate   ");
37         
38 /*        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.example_appwidget);
39         long date = System.currentTimeMillis();
40         SimpleDateFormat format = new SimpleDateFormat("yyyy--MM--dd hh:mm:ss");
41         String text = format.format(date);
42         
43         views.setTextViewText(R.id.tv_time, text);
44         
45         Intent intent = new Intent(context,MainActivity.class);
46         PendingIntent pendingIntent = PendingIntent.getActivity(context, 100, intent, 0);
47         views.setOnClickPendingIntent(R.id.tv_time, pendingIntent);
48         // 更新widget
49         appWidgetManager.updateAppWidget(appWidgetIds, views);*/
50     }
51     
52     /**
53      * 删除
54      */
55     @Override
56     public void onDeleted(Context context, int[] appWidgetIds) {
57         // TODO Auto-generated method stub
58         super.onDeleted(context, appWidgetIds);
59         Log.i("i", "  onDeleted   ");
60     }
61     
62     /**
63      * 不可用
64      */
65     @Override
66     public void onDisabled(Context context) {
67         // TODO Auto-generated method stub
68         super.onDisabled(context);
69         Log.i("i", "  onDisabled   ");
70         
71         // 停止服务
72         Intent intent = new Intent(context,MyService.class);
73         context.stopService(intent);
74     }
75 }

6.服务代码：

 1 package com.android.hzy.widget;
 2 
 3 import java.text.SimpleDateFormat;
 4 import java.util.Timer;
 5 import java.util.TimerTask;
 6 
 7 import android.app.PendingIntent;
 8 import android.app.Service;
 9 import android.appwidget.AppWidgetManager;
10 import android.content.ComponentName;
11 import android.content.Intent;
12 import android.os.IBinder;
13 import android.widget.RemoteViews;
14 
15 public class MyService extends Service {
16     
17     private Timer timer;
18     private TimerTask task = new TimerTask(){
19 
20         @Override
21         public void run() {
22             // TODO Auto-generated method stub
23             AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(getApplicationContext());
24             
25             RemoteViews views = new RemoteViews(getPackageName(), R.layout.example_appwidget);
26             long date = System.currentTimeMillis();
27             SimpleDateFormat format = new SimpleDateFormat("yyyy--MM--dd hh:mm:ss");
28             String text = format.format(date);
29             
30             views.setTextViewText(R.id.tv_time, text);
31             
32             Intent intent = new Intent(getApplicationContext(),MainActivity.class);
33             PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 100, intent, 0);
34             views.setOnClickPendingIntent(R.id.tv_time, pendingIntent);
35             
36             ComponentName provider = new ComponentName(getApplicationContext(), ExampleAppWidgetProvider.class);
37             // 更新appWidget
38             appWidgetManager.updateAppWidget(provider, views);
39         }
40         
41     };
42     
43     @Override
44     public void onCreate() {
45         // TODO Auto-generated method stub
46         super.onCreate();
47         
48         // 开启线程
49         timer = new Timer();
50         timer.schedule(task, 1000, 1000);
51         
52     }
53     
54     
55     @Override
56     public IBinder onBind(Intent arg0) {
57         // TODO Auto-generated method stub
58         return null;
59     }
60     
61     @Override
62     public void onDestroy() {
63         // TODO Auto-generated method stub
64         super.onDestroy();
65         timer.cancel();
66         task = null;
67     }
68 
69 }

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原文地址：https://www.cnblogs.com/androidez/p/2908805.html