Android自学之路——Service与IntentService

Posted 2020-06-30

 
A)MainActivity部分的代码
1 package com.example.cms.intentservice;
 2 
 3 import android.content.Intent;
 4 import android.support.v7.app.AppCompatActivity;
 5 import android.os.Bundle;
 6 import android.view.View;
 7 import android.widget.Button;
 8 
 9 public class MainActivity extends AppCompatActivity {
10     private Button startService;
11     private Button startIntentService;
12 
13     @Override
14     protected void onCreate(Bundle savedInstanceState) {
15         super.onCreate(savedInstanceState);
16         setContentView(R.layout.activity_main);
17         startService= (Button) findViewById(R.id.Service);
18         startIntentService= (Button) findViewById(R.id.IntentService);
19         startService.setOnClickListener(new View.OnClickListener() {
20             @Override
21             public void onClick(View v) {
22                 startService();
23             }
24         });
25         startIntentService.setOnClickListener(new View.OnClickListener() {
26             @Override
27             public void onClick(View v) {
28                 startIntentService();
29             }
30         });
31     }
32     public void startService() {
33         Intent intent = new Intent(this, MyService.class);
34         startService(intent);
35     }
36     public void startIntentService(){
37         Intent intent=new Intent(this,MyIntentService.class);
38         startService(intent);
39     }
40 }

B）MyService部分的代码

 1 package com.example.cms.intentservice;
 2 
 3 import android.app.Service;
 4 import android.content.Intent;
 5 import android.os.IBinder;
 6 import android.support.annotation.Nullable;
 7 
 8 /**
 9  * Created by CMS on 2016/3/28.
10  */
11 public class MyService extends Service {
12     @Nullable
13     @Override
14     public IBinder onBind(Intent intent) {
15         return null;
16     }
17 
18     @Override
19     public int onStartCommand(Intent intent, int flags, int startId) {
20         //使用线程暂停的方式 模拟耗时任务 暂停20秒
21         //普通的Service的执行会堵塞主线程 因此执行此方法会出现ANR异常
22         long endTime=System.currentTimeMillis()+20*1000;
23         System.out.println("onStart");
24         while(System.currentTimeMillis()<endTime){
25             synchronized (this){
26                 try {
27                     wait(endTime-System.currentTimeMillis());
28                 } catch (InterruptedException e) {
29                     e.printStackTrace();
30                 }
31             }
32         }
33         System.out.println("---耗时任务执行完成----");
34         return START_STICKY;
35     }
36 }

C）MyIntentservice部分的代码

package com.example.cms.intentservice;

import android.app.IntentService;
import android.content.Intent;
import android.content.IntentSender;

/**
 * Created by CMS on 2016/3/28.
 */
public class MyIntentService extends IntentService {

    public MyIntentService() {
        super("MyIntentService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        //IntentService会使用单独的线程来执行此方法的代码
        //不会阻塞主线程 所以不会出现ABR异常
        long endTime=System.currentTimeMillis()+20*1000;
        System.out.println("onHandleIntent");
        while(System.currentTimeMillis()<endTime){
            synchronized (this){
                try {
                    wait(endTime-System.currentTimeMillis());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
        System.out.println("耗时任务执行完成");
    }
}