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Android IntentService使用

Android IntentService使用

作者: 荞麦穗 | 来源:发表于2017-11-24 21:34 被阅读0次

IntentService使用代码

package com.zhy.blogcodes.intentservice;

import android.app.IntentService;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class UploadImgService extends IntentService
{
    private static final String ACTION_UPLOAD_IMG = "com.zhy.blogcodes.intentservice.action.UPLOAD_IMAGE";
    public static final String EXTRA_IMG_PATH = "com.zhy.blogcodes.intentservice.extra.IMG_PATH";

    public static void startUploadImg(Context context, String path)
    {
        Intent intent = new Intent(context, UploadImgService.class);
        intent.setAction(ACTION_UPLOAD_IMG);
        intent.putExtra(EXTRA_IMG_PATH, path);
        context.startService(intent);
    }


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

    @Override
    protected void onHandleIntent(Intent intent)
    {//运行在HandlerThread的Thread中,可以进行耗时操作。
        if (intent != null)
        {
            final String action = intent.getAction();
            if (ACTION_UPLOAD_IMG.equals(action))
            {
                final String path = intent.getStringExtra(EXTRA_IMG_PATH);
                handleUploadImg(path);
            }
        }
    }

    private void handleUploadImg(String path)
    {
        try
        {
            //模拟上传耗时
            Thread.sleep(3000);

            Intent intent = new Intent(IntentServiceActivity.UPLOAD_RESULT);
            intent.putExtra(EXTRA_IMG_PATH, path);
            sendBroadcast(intent);

        } catch (InterruptedException e)
        {
            e.printStackTrace();
        }


    }

    @Override
    public void onCreate()
    {
        super.onCreate();
        Log.e("TAG","onCreate");
    }

    @Override
    public void onDestroy()
    {
        super.onDestroy();
        Log.e("TAG","onDestroy");
    }
}

主要就是继承IntentService,然后复写onHandleIntent方法,根据传入的intent来选择具体的操作。
调用 UploadImgService.startUploadImg(this, path);

IntentService源码解析
package android.app;

import android.content.Intent;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;


public abstract class IntentService extends Service {
    private volatile Looper mServiceLooper;
    private volatile ServiceHandler mServiceHandler;
    private String mName;
    private boolean mRedelivery;
    //消息处理handler
    private final class ServiceHandler extends Handler {
        public ServiceHandler(Looper looper) {
            super(looper);
        }

        @Override
        public void handleMessage(Message msg) {
            onHandleIntent((Intent)msg.obj);
            stopSelf(msg.arg1);
        }
    }


    public IntentService(String name) {
        super();
        mName = name;
    }


    public void setIntentRedelivery(boolean enabled) {
        mRedelivery = enabled;
    }

    @Override
    public void onCreate() {
                super.onCreate();
        HandlerThread thread = new HandlerThread("IntentService[" + mName + "]");//IntentService[" + mName + "]"线程名
        thread.start();

        mServiceLooper = thread.getLooper();
        //通过HandlerThread的Looper来创建Handler,使handler在属于子线程
        mServiceHandler = new ServiceHandler(mServiceLooper);
    }

    @Override
    public void onStart(Intent intent, int startId) {
        Message msg = mServiceHandler.obtainMessage();
        msg.arg1 = startId;
        msg.obj = intent;
        mServiceHandler.sendMessage(msg);
    }


    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        onStart(intent, startId);
        return mRedelivery ? START_REDELIVER_INTENT : START_NOT_STICKY;
    }

    @Override
    public void onDestroy() {
        mServiceLooper.quit();
    }


    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }


    protected abstract void onHandleIntent(Intent intent);
}

IntentService特点:
1、可以发消息来有选择的执行方法。启动操作。
2、属于Service,四大组件之一,不会被轻易回收
3、可以是Service进行耗时操作。


引用:http://blog.csdn.net/lmj623565791/article/details/47143563

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