使用TransitionDrawable实现多张图片淡入淡出效果

//讲需要切换的两张图片直接给TransitionDrawable对象
TransitionDrawable transitionDrawable = new TransitionDrawable(new Drawable[]{getResources().getDrawable(R.drawable.advertiseone),getResources().getDrawable(R.drawable.advertisetwo)});
//一样用
imgAdvertise.setImageDrawable(transitionDrawable);
//切换图片的时间间隔
transitionDrawable.startTransition(3000);

package com.coofond.carservice;

import android.content.Intent;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.TransitionDrawable;
import android.os.Build;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

import com.coofond.carservice.mine.ui.LoginAct;

/**
 * Created by IBM on 2016/10/7.
 */

public class WelcomeAct extends AppCompatActivity {
  private TextView tvTimecount;
  private ImageView imgAdvertise;
  private int adTime = 6000;//倒计时秒数
  private int timeInterval = 1000;//倒计时间隔
  private CountDownTimer mTimer;//计时器
  private int change = 0;//记录下标
  private int[] ids = new int[]{R.drawable.advertiseone, R.drawable.advertisetwo, R.drawable.advertisethree};
  private Drawable[] drawables;//图片集合
  private Thread mThread;//线程
  private boolean mThreadFlag = true;//线程结束标志符

  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.act_welcome);
    initView();
    initData();
    initEvent();
  }

  //定义hander
  private Handler mHandler = new Handler(new Handler.Callback() {
    @Override
    public boolean handleMessage(Message msg) {
      int duration = msg.arg1;
      TransitionDrawable transitionDrawable = new TransitionDrawable(new Drawable[]{drawables[change % ids.length],
          drawables[(change + 1) % ids.length]});
      change++;//改变标识位置
      imgAdvertise.setImageDrawable(transitionDrawable);
      transitionDrawable.startTransition(duration);
      return false;
    }
  });

  //开启线程发送消息，让transition一直在改变
  private class MyRunnable implements Runnable {
    @Override
    public void run() {
      //这个while(true)是做死循环
      while (mThreadFlag) {
        int duration = 1000;//改变的间隔
        Message message = mHandler.obtainMessage();
        message.arg1 = duration;
        mHandler.sendMessage(message);
        try {
          Thread.sleep(duration);
          //隔duration秒发送一次
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
    }
  }

  private void initView() {
    tvTimecount = (TextView) findViewById(R.id.tv_advert);
    imgAdvertise = (ImageView) findViewById(R.id.iv_advetise);
    //填充图片
    drawables=new Drawable[ids.length];
    for (int i = 0; i < ids.length; i++) {
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        drawables[i] = getDrawable(ids[i]);
      } else {
        drawables[i] = getResources().getDrawable(ids[i]);
      }
    }
  }
  private void initData() {
    // 初始化计时器,第一个参数是共要倒计时的秒数，第二个参数是倒计时的间隔
    mTimer = new CountDownTimer(adTime, timeInterval) {
      // 倒计时开始时要做的事情，参数m是直到完成的时间
      @Override
      public void onTick(long millisUntilFinished) {
        tvTimecount.setText("" + millisUntilFinished / 1000 + "s跳过广告");
      }
      // 结束计时后要做的工作
      @Override
      public void onFinish() {
        jumpActivity();
      }
    };
    //开启计时器
    mTimer.start();
    //开启线程，改变transition,切换图片
    mThread= new Thread(new MyRunnable());
    mThread.start();
  }

  private void initEvent() {
    tvTimecount.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        mTimer.cancel();
        jumpActivity();
      }
    });
  }

  // 跳转页面
  private void jumpActivity() {
    //如果还没结束当前的页面，就结束
    if (!isFinishing()) {
      finish();
    }
    Intent it = new Intent(WelcomeAct.this, LoginAct.class);
    startActivity(it);
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    //mThread.stop(); 不推荐使用
    mThreadFlag=false;//结束线程

  }
}