android开发之service的使用

来源:爱站网时间:2023-01-19编辑:网友分享
小编今天来给大家说说看android开发之service的使用内容,对这方面比较感兴趣的小伙伴可以看看爱站技术频道小编所整理的资料,相信这篇文章一定不会让你失望的。

Service的生命周期 (适用于2.1及以上)

1. 被startService的
无论是否有任何活动绑定到该Service,都在后台运行。onCreate(若需要) -> onStart(int id, Bundle args).  多次startService,则onStart调用多次,但不会创建多个Service实例,只需要一次stop。该Service一直后台运行,直到stopService或者自己的stopSelf()或者资源不足由平台结束。

2. 被bindService的
调用bindService绑定,连接建立服务一直运行。未被startService只是BindService,则onCreate()执行,onStart(int,Bundle)不被调用;这种情况下绑定被解除,平台就可以清除该Service(连接销毁后,会导致解除,解除后就会销毁)。

3. 被启动又被绑定
类似startService的生命周期,onCreate onStart都会调用。

4. 停止服务时
stopService时显式onDestroy()。或不再有绑定(没有启动时)时隐式调用。有bind情况下stopService()不起作用。

以下是一个简单的实现例子,某些部分需要配合logcat观察。
AcMain.java


package jtapp.myservicesamples;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class AcMain extends Activity implements OnClickListener {
        private static final String TAG = "AcMain";
        private Button btnStart;
        private Button btnStop;
        private Button btnBind;
        private Button btnExit;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        findView();
    }
        private void findView() {
                btnStart = (Button) findViewById(R.id.Start);
        btnStop = (Button) findViewById(R.id.Stop);
        btnBind = (Button) findViewById(R.id.Bind);
        btnExit = (Button) findViewById(R.id.Exit);

        btnStart.setOnClickListener(this);
        btnStop.setOnClickListener(this);
        btnBind.setOnClickListener(this);
        btnExit.setOnClickListener(this);
        }
        @Override
        public void onClick(View v) {
                Intent intent = new Intent("jtapp.myservicesamples.myservice");
                switch(v.getId()) {
                case R.id.Start:
                        startService(intent);
                        Toast.makeText(this,
                                        "myservice running " + MyService.msec/1000.0 + "s.",
                                        Toast.LENGTH_LONG).show();
                        break;
                case R.id.Stop:
                        stopService(intent);
                        Toast.makeText(this,
                                        "myservice running " + MyService.msec/1000.0 + "s.",
                                        Toast.LENGTH_LONG).show();
                        break;
                case R.id.Bind:
                        bindService(intent, sc, Context.BIND_AUTO_CREATE);
                        break;
                case R.id.Exit:
                        this.finish();
                        break;
                }
        }

        private MyService serviceBinder;

        private ServiceConnection sc = new ServiceConnection() {
                @Override
                public void onServiceDisconnected(ComponentName name) {
                        Log.d(TAG, "in onServiceDisconnected");
                        serviceBinder = null;
                }
                @Override
                public void onServiceConnected(ComponentName name, IBinder service) {
                        Log.d(TAG, "in onServiceConnected");
                        serviceBinder = ((MyService.MyBinder)service).getService();
                }
        };
        @Override
        protected void onDestroy() {
                //this.unbindService(sc);
                //this.stopService(
                //                new Intent("jtapp.myservicesamples.myservice"));
                super.onDestroy();
        }
}

 

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical" android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <TextView android:layout_width="fill_parent"
                android:layout_height="wrap_content" android:text="@string/hello" />
        <Button android:text="Start MyService" android:id="@+id/Start"
                android:layout_width="wrap_content" android:layout_height="wrap_content"/>
        <Button android:text="Stop MyService" android:id="@+id/Stop"
                android:layout_width="wrap_content" android:layout_height="wrap_content"/>
        <Button android:text="Bind MyService" android:id="@+id/Bind"
                android:layout_width="wrap_content" android:layout_height="wrap_content"/>
        <Button android:text="Exit AcMain" android:id="@+id/Exit"
                android:layout_width="wrap_content" android:layout_height="wrap_content"/>
</LinearLayout>

 

MyService.java

package jtapp.myservicesamples;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
public class MyService extends Service {
        private static final String TAG = "MyService";
        public static long msec = 0;
        private boolean bThreadRunning = true;

       
        private final IBinder binder = new MyBinder();
        public class MyBinder extends Binder {
                MyService getService() {
                        return MyService.this;
                }
        }
        @Override
        public IBinder onBind(Intent intent) {
                return binder;
        }
        @Override
        public void onCreate() {
                new Thread(new Runnable(){
                        @Override
                        public void run() {
                                while (bThreadRunning) {
                                        try {
                                                Thread.sleep(100);
                                        } catch (InterruptedException e) {
                                        }
                                        Log.i(TAG, "myservice running " + (msec+=100) + "ms.");
                                }
                        }
                }).start();
        }
        @Override
        public void onDestroy() {
                bThreadRunning = false;
                super.onDestroy(); // 可以不用
        }
}

 

AnndroidManifest.xml


<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="jtapp.myservicesamples" android:versionCode="1"
        android:versionName="1.0">
        <application android:icon="@drawable/icon" android:label="@string/app_name"
                android:debuggable="true">
                <activity android:name=".AcMain" android:label="@string/app_name">
                        <intent-filter>
                                <action android:name="android.intent.action.MAIN" />
                                <category android:name="android.intent.category.LAUNCHER" />
                        </intent-filter>
                </activity>
                <service android:name="MyService">
                        <intent-filter>
                                <action android:name="jtapp.myservicesamples.myservice"></action>
                        </intent-filter>
                </service>
        </application>
</manifest>

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