Handler消息传递机制

package com.android.xiong.gridlayoutTest;

import java.sql.Time;

import java.util.Timer;

import java.util.TimerTask;

import android.app.Activity;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.widget.ImageView;

public class AutoPlayActivity extends Activity {

/**

* @author zm

*/

private ImageView iv_autoplay;

//存放的图片资源数组

private int[] images = new int[] { R.drawable.gril1, R.drawable.gril2,

R.drawable.gril3, R.drawable.gril4, R.drawable.gril5,

};

       //当前图片的索引

private int currentImg = 0;

@Override

protected void onCreate(Bundle savedInstanceState) {

// TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_img);

initView();

final Handler hanlder=new Handler(){

public void handleMessage(android.os.Message msg) {

if(msg.what==0x1233){

//动态的显示图片

iv_autoplay.setScaleType(ImageView.ScaleType.FIT_XY);

iv_autoplay.setImageResource(images[currentImg++%images.length]);

}

};

};

new Timer().schedule(new TimerTask() {

@Override

public void run() {

// 发送一条空消息

hanlder.sendEmptyMessage(0x1233);

}

},0, 1000);

}

private void initView() {

// 初始化View

iv_autoplay = (ImageView) findViewById(R.id.iv_autoplay);

}

}

布局文件activity_img

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    <ImageView

        android:id="@+id/iv_autoplay"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:layout_gravity="center"

        android:layout_marginTop="30dp"

        android:src="@drawable/gril2" />

</LinearLayout>

效果如下图所示