android onstart方法没走 android service onstartcommand

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lgmyxbjfu 2023-11-28 22:08:00

文章标签 android onstart方法没走 android 线程服务 ide 文章分类 Android 移动开发

1、通过startservice方法启动一个服务，service不能自己启动自己。若在一个服务中启动一个activity则，必须是申明一个全新的activity任务TASK。通过startservice方法启动的服务不会随着启动组件的消亡而消亡，而是一直运行着。

Service生命周期 onCreate()-------->onStartCommand()----------->onDestroy()

startService()启动一个服务后，若在该服务做耗时操作且没有写线程，则会导致主线程阻塞！

服务启动运行后会一直运行onStartCommand()方法。

2、用bindService启动一个服务，该服务和activity是绑定在一起的：启动时，先调用onCreate()------>onBind()--------->onServiceConnected()，启动服务的组件消亡，服务也就消亡了。

3、AIDL服务调用方式

demo下载地址:

1)服务端代码:

首先定义一个接口描述语言的接口：

package com.example.service;
interface DataService{
double getData(String arg);

}

然后定义服务组件代码：

/**
 *Version:
 *author:YangQuanqing
 *Data:
 */
package com.example.android_aidl_service;

import com.example.service.DataService;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.os.RemoteException;

/**
 * @author YangQuanqing yqq
 *
 */
public class MyService extends Service {

	
	@Override
	public IBinder onBind(Intent arg0) {
		<span style="color:#ff0000;">//返回binder由didl文件生成</span>
		return binder;
	}
	//定义给客户端调用的方法 (aidl文件)
	Binder binder=new <span style="color:#ff0000;">DataService.Stub()</span> {
		
		@Override
		public double getData(String arg) throws RemoteException {
			if(arg=="a"){
				return 1;
			}
			if(arg=="b"){
				return 2;
			}
			
			return 0;
		}
	};

}

服务端的清单文件：

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.android_aidl_service.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>
        <service 
            android:name="com.example.android_aidl_service.MyService"
            >
            <intent-filter>
                <!-- 意图过滤器要把aidl包名加类名 -->
                <action android:name="com.example.service.DataService"/>
            </intent-filter>
        </service>
    </application>

</manifest>

客户端编码：

把aidl文件包拷贝到客户端，客户端代码如下：

package com.example.android_aidl_client;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

import com.example.service.DataService;

public class MainActivity extends Activity {
	private Button btn1,btn2;
	//定义一个AIDL实例
	private DataService dataService;
	private TextView tv;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btn1=(Button)this.findViewById(R.id.button1);
		btn2=(Button)this.findViewById(R.id.button2);
		tv=(TextView)this.findViewById(R.id.textView1);
		//绑定服务
		btn1.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				Intent intent=new Intent(DataService.class.getName());
				//启动服务
				bindService(intent, conn, BIND_AUTO_CREATE);
			}
		});
		//调用服务的方法
		btn2.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
			try {
				int result=(int) dataService.getData("a");
				tv.setText(result+"");
			} catch (RemoteException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
				
			}
		});
	}
//客户端与服务交互
	private ServiceConnection conn=new ServiceConnection() {
		
		@Override
		public void onServiceDisconnected(ComponentName name) {
			
			
		}
		
		@Override
		public void onServiceConnected(ComponentName name, IBinder service) {
			//传入service
			dataService=DataService.Stub.asInterface(service);
		}
	};
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

这样就可以完成进程间通信了。

4、用bindService启动服务并访问本地服务的方法。

访问界面代码：

package com.example.android_service_binder;

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.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

import com.example.android_service_binder.MyService.LocalBinder;

public class MainActivity extends Activity {
	//销毁绑定
	@Override
	protected void onStop() {
		super.onStop();
		if(flag)
		{
			//解除绑定
			unbindService(serviceConnection);
			flag=false;
		}
		
	}


	//绑定Service
	@Override
	protected void onStart() {
		// TODO Auto-generated method stub
		super.onStart();
		/*Intent intent=new Intent(MainActivity.this,MyService.class);
		//启动service
		bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);*/
	}


	

	private Button btnBinder=null;
	private Button btnCall=null;
	private TextView tv=null;
	private MyService myService;//service实例
	private boolean flag=false;//默认不绑定
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btnBinder=(Button)this.findViewById(R.id.button1);
		btnCall=(Button)this.findViewById(R.id.button2);
		tv=(TextView)this.findViewById(R.id.textView1);
		btnBinder.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				Intent intent=new Intent(MainActivity.this,MyService.class);
				//启动service
				bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
			}
		});
		//调用service方法
		btnCall.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				//处于绑定状态
				if(flag)
				{
					int result=myService.getRandom();
					tv.setText("<<<<<"+result);
				}
			}
		});
		
	}
	
	
	private ServiceConnection serviceConnection= new ServiceConnection(){
		//连接
		@Override
		public void onServiceConnected(ComponentName arg0, IBinder iBinder) {
//获得服务的The IBinder of the Service's communication channel, which you can now make calls on.
			LocalBinder binder=(LocalBinder) iBinder;
			//获得服务
			myService=binder.getService();
			
			flag=true;
			
		}
		//不连接
		@Override
		public void onServiceDisconnected(ComponentName arg0) {
			flag=false;
			
		}
		
	};
	

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

服务组件代码：

/**
 *Version:
 *author:YangQuanqing
 *Data:
 */
package com.example.android_service_binder;

import java.util.Random;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;

/**
 * @author YangQuanqing yqq
 *
 */
public class MyService extends Service {

	private final LocalBinder lb=new LocalBinder();
	private final Random num=new Random();
	
	@Override
	public IBinder onBind(Intent arg0) {
		// 返回本地Binder的子类实例
		return  lb;
	}
	//定义一个本地Binder类继承Binder
	public class LocalBinder extends Binder{
		//获得Servie子类当前实例给客户端
		public MyService getService(){
		return MyService.this;
		}
		
	}
	public int getRandom(){
		
		return num.nextInt(98);
	}

}

通过该demo可以访问本地服务里面的方法。

demo下载地址：

5、IntentService

本质是开启一个线程来完成耗时操作。

IntentService生命周期:

onCreate()------->onStartCommand()--------->onHandleIntent()--------->onDestroy()

/**
 *Version:
 *author:YangQuanqing
 *Data:
 */
package com.example.android_intentservice;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import android.app.IntentService;
import android.content.Intent;
import android.os.Environment;
import android.widget.Toast;

/**
 * @author YangQuanqing  不需要开启线程(看源码知道是自己封装了开启线程)，不需要关闭服务，自己关闭,单线程下载数据
 * 
 * 一定要记得实例化！！！
 */
public class DownLoadService extends IntentService {

	@Override
	public void onCreate() {
		// TODO Auto-generated method stub
		super.onCreate();
	}

	public DownLoadService() {
		super("DownLoadService");

	}

	// 只需复写如下方法

	// 在该方法中执行操作
	@Override
	protected void onHandleIntent(Intent intent) {
		// 获得提取网络资源的实例
		HttpClient httpClient = new DefaultHttpClient();
		// 设置请求方式
		HttpPost httpPost = new HttpPost(intent.getStringExtra("url"));
		// 设置存储路径
		File file = new File(Environment.getExternalStorageDirectory(),
				"IntentService.gif");
		// 定义输出流用于写
		FileOutputStream fileOutputStream = null;
		byte[] data = null;// 网络数据
		
		try {
			// 执行请求获得响应
			HttpResponse httpResponse = httpClient.execute(httpPost);
			// 判断响应状态码
			if (httpResponse.getStatusLine().getStatusCode() == 200) {
				// 获得响应实体
				HttpEntity httpEntity = httpResponse.getEntity();
				// 获得网络数据
				data = EntityUtils.toByteArray(httpEntity);
				// 判断SD卡是否可用
				if (Environment.getExternalStorageState().equals(
						Environment.MEDIA_MOUNTED)) {
					// 写入SD卡
					fileOutputStream=new FileOutputStream(file);
					fileOutputStream.write(data, 0, data.length);
					//Toast.makeText( DownLoadService.this,"下载完成", Toast.LENGTH_LONG).show();
					Toast.makeText( getApplicationContext(),"下载完成", Toast.LENGTH_LONG).show();
				}
			}
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {

			if (fileOutputStream != null) {
				try {
					fileOutputStream.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}

	}

}

调用服务界面：

package com.example.android_intentservice;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

	private Button btn_intent=null;
	private String url="http://www.baidu.com/img/bdlogo.gif";
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btn_intent=(Button)this.findViewById(R.id.button1);
		btn_intent.setOnClickListener(new OnClickListener(){

			@Override
			public void onClick(View arg0) {
				Intent intent=new Intent(MainActivity.this,DownLoadService.class);
				intent.putExtra("url", url);
				startService(intent);
				
				
			}
			
			
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

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