Android Service实时向Activity传递数据

深藏阁楼爱情的钟 2022-03-28 08:24 261阅读 0赞

演示一个案例，需求如下：  
在Service组件中创建一个线程，该线程用来生产数值，每隔1秒数值自动加1，然后把更新后的数值在界面上实时显示。

**步骤如下：**  
1、新建一个android项目工程，取名为demo。  
2、新建一个Service类，用来实时生产数值，供界面实时显示。

package com.ljq.activity;
     
    import android.app.Service;
    import android.content.Intent;
    import android.os.IBinder;
    import android.util.Log;
     
    public class CountService extends Service {
     private int count = 0;
     private boolean threadDisable=false;
     
     @Override
     public void onCreate() {
      super.onCreate();
       
      new Thread(new Runnable() {
       @Override
       public void run() {
        while (!threadDisable) {
         try {
          Thread.sleep(1000);
         } catch (InterruptedException e) {
          e.printStackTrace();
         }
         count++;
         Log.v("CountService", "Count is " + count);
          
         //发送广播
         Intent intent=new Intent();
         intent.putExtra("count", count);
         intent.setAction("com.ljq.activity.CountService");
         sendBroadcast(intent);
        }
       }
      }).start();
     
     }
     
     @Override
     public IBinder onBind(Intent intent) {
      return null;
     }
     
     @Override
     public void onDestroy() {
      super.onDestroy();
      count=0;
      threadDisable = true;
      Log.v("CountService", "on destroy");
     }
     
     
    }

3、新建一个Activity类，显示数据。

package com.ljq.activity;
     
    import android.app.Activity;
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
     
    public class MainActivity extends Activity {
     private EditText editText=null;
     private MyReceiver receiver=null;
      
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
             
            editText=(EditText)findViewById(R.id.editText);
             
            //启动服务
            startService(new Intent(MainActivity.this, CountService.class));
             
      //注册广播接收器
      receiver=new MyReceiver();
      IntentFilter filter=new IntentFilter();
      filter.addAction("com.ljq.activity.CountService");
      MainActivity.this.registerReceiver(receiver,filter);
        }
         
        @Override
     protected void onDestroy() {
         //结束服务
            stopService(new Intent(MainActivity.this, CountService.class));
      super.onDestroy();  
     }
         
        /**
         * 获取广播数据
         * 
         * @author jiqinlin
         *
         */
        public class MyReceiver extends BroadcastReceiver {
         @Override
         public void onReceive(Context context, Intent intent) {
          Bundle bundle=intent.getExtras();
          int count=bundle.getInt("count");
          editText.setText(count+"");    
         }
        }
     
          
         
     
    }

4、main.xml布局文件

<?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">
        <EditText android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:cursorVisible="false"
            android:editable="false"
            android:id="@+id/editText"/>
     
    </LinearLayout>

5、清单文件

<?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.ljq.activity"
          android:versionCode="1"
          android:versionName="1.0">
        <application android:icon="@drawable/icon" android:label="@string/app_name">
            <activity android:name=".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 =".CountService" />
     
        </application>
        <uses-sdk android:minSdkVersion="7" />
     
    </manifest>

效果如下：

![21102955-0f3e3bf4957a486b90592ceb20bcef33.png][]

[21102955-0f3e3bf4957a486b90592ceb20bcef33.png]: /images/20220328/65d96296943548a1964b6f492036e38b.png