android api分析22 Service

最新推荐文章于 2023-05-15 23:11:58 发布

原创最新推荐文章于 2023-05-15 23:11:58 发布 · 975 阅读

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本文详细介绍了在Android应用中如何使用Service，并通过代码示例展示了Service的创建、绑定、解绑以及获取Service状态的过程。文章还讨论了Service的生命周期管理和线程操作，帮助开发者更好地理解和掌握Service的使用技巧。

public class MainActivity extends Activity {
	
	Button bind, unbind, getServiceStatus;
	// 保持所启动的Service的IBinder对象
	BindService.MyBinder binder;
	// 定义一个ServiceConnection对象
	
	private ServiceConnection conn = new ServiceConnection() {
		// 当该Activity与Service连接成功时回调该方法
		@Override
		public void onServiceConnected(ComponentName name, IBinder service) {
			Log.e("service02", "MainActivity onServiceConnected");
			// 获取Service的onBind方法所返回的MyBinder对象
			binder = (BindService.MyBinder) service;
		}

		// 当该Activity与Service断开连接时回调该方法
		@Override
		public void onServiceDisconnected(ComponentName name) {
			Log.e("service02", "MainActivity onServiceDisconnected");
		}
	};

	@Override
	public void onCreate(Bundle savedInstanceState) {
		Log.e("service02", "MainActivity onCreate");
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		// 获取程序界面中的start、stop、getServiceStatus按钮
		bind = (Button) findViewById(R.id.bind);
		unbind = (Button) findViewById(R.id.unbind);
		getServiceStatus = (Button) findViewById(R.id.getServiceStatus);
		// 创建启动Service的Intent
		final Intent intent = new Intent();
		// 为Intent设置Action属性
		intent.setAction("org.crazyit.service.BIND_SERVICE");
		bind.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View source) {
				// 绑定指定Serivce
				bindService(intent, conn, Service.BIND_AUTO_CREATE);
			}
		});
		unbind.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View source) {
				// 解除绑定Serivce
					unbindService(conn);
			}
		});
		getServiceStatus.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View source) {
				// 获取、并显示Service的count值
				Toast.makeText(MainActivity.this,
						"Serivce的count值为：" + binder.getCount(), 4000).show();
			}
		});
	}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center_horizontal"
    android:orientation="horizontal" >

    <Button
        android:id="@+id/bind"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="bind" />

    <Button
        android:id="@+id/unbind"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="unbind" />

    <Button
        android:id="@+id/getServiceStatus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="getServiceStatus" />

</LinearLayout>

public class BindService extends Service
{
	private int count;
	private boolean quit;
	// 定义onBinder方法所返回的对象
	private MyBinder binder = new MyBinder();
	// 通过继承Binder来实现IBinder类
	public class MyBinder extends Binder
	{
		public int getCount()
		{
			Log.e("service02", "BindService getCount");
			// 获取Service的运行状态：count
			return count;
		}
	}
	// 必须实现的方法
	@Override
	public IBinder onBind(Intent intent)
	{
		Log.e("service02", "BindService onBind");
		// 返回IBinder对象
		return binder;
	}
	// Service被创建时回调该方法。
	@Override
	public void onCreate()
	{
		super.onCreate();
		Log.e("service02", "BindService onCreate");
		// 启动一条线程、动态地修改count状态值
		new Thread()
		{
			@Override
			public void run()
			{
				while (!quit)
				{
					try
					{
						Thread.sleep(1000);
					}
					catch (InterruptedException e)
					{
					}
					count++;
				}
			}
		}.start();		
	}
	// Service被断开连接时回调该方法
	@Override
	public boolean onUnbind(Intent intent)
	{
		Log.e("service02", "BindService onUnbind");
		return true;
	}
	// Service被关闭之前回调。
	@Override
	public void onDestroy()
	{
		super.onDestroy();
		this.quit = true;
		Log.e("service02", "BindService onDestroy");
	}
	
	@Override
	public void onRebind(Intent intent) 
	{
		super.onRebind(intent);
		this.quit = true;
		Log.e("service02", "BindService onRebind");
	}	
}

<service android:name=".BindService">
			<intent-filter>
				<!-- 为该Service组件的intent-filter配置action -->
				<action android:name="org.crazyit.service.BIND_SERVICE" />
			</intent-filter>	
		</service>

ServiceConnection

监视服务的状态

Binder extends Object implements IBinder

点击bind
BindService onCreate()
BindService onBind()
MainActivity onServiceConnected()

之后 count在新线程中值会一直增加

点击unbind
BindService onUnbind()
BindService onDestroy()
count值停止增加

点击getServiceStatus
BindService getCount()