Android 简单启动图

现在市面上很多应用都有启动图。启动图的作用可以介绍应用，也可以给用户进入应用一个缓冲的作用。
下边看一下简单启动图的效果：

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public class EntryActivity extends Activity {
    @Bind(R.id.iv_entry)
    ImageView mSplashImage;

    private static final int ANIMATION_TIME = 2000;

    private static final float SCALE_END = 1.13F;

    private static final int[] IMAGES = {
            R.drawable.ic_hotbitmapgg,
            R.drawable.splash0,
            R.drawable.splash1,
            R.drawable.splash2,
            R.drawable.splash3,
            R.drawable.splash4,
            R.drawable.splash5,
            R.drawable.splash6,
            R.drawable.splash7,
            R.drawable.splash8,
            R.drawable.splash9,
            R.drawable.splash10,
            R.drawable.splash11,
            R.drawable.splash12,
            R.drawable.splash13,
            R.drawable.splash14,
            R.drawable.splash15,
            R.drawable.splash16,
    };


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_entry);
        ButterKnife.bind(this);
        Random random = new Random(SystemClock.elapsedRealtime());
        mSplashImage.setImageResource(IMAGES[random.nextInt(IMAGES.length)]);
        Observable.timer(1, TimeUnit.SECONDS)
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Action1(){
                    @Override
                    public void call(Long aLong) {
                        startAnim();
                    }
                });
    }

    private void startAnim() {

        ObjectAnimator animatorX=ObjectAnimator.ofFloat(mSplashImage,"scaleX",1f,SCALE_END);
        ObjectAnimator animatorY=ObjectAnimator.ofFloat(mSplashImage,"scaleY",1f,SCALE_END);
        AnimatorSet set=new AnimatorSet();
        set.setDuration(ANIMATION_TIME).play(animatorX).with(animatorY);
        set.start();
        set.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) {

            }

            @Override
            public void onAnimationEnd(Animator animation) {
                startActivity(new Intent(EntryActivity.this,MainActivity.class));
                EntryActivity.this.finish();

            }

            @Override
            public void onAnimationCancel(Animator animation) {

            }

            @Override
            public void onAnimationRepeat(Animator animation) {

            }
        });
    }
}

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1.EntryActivity 不要继承AppCompatActivity，因为AppCompatActivity会去加载主题，导致页面卡顿。

2.该activity只有一个iamgeview控件。

3.Observable.timer()Handler定时发送消息，以上代码就是1秒后发送

4.使用到了ObjectAnimator的缩放，了解ObjeAnimator的更多使用，

5. 一个AnimationSet包含了一系列的Animation,设置时间,设置监听(动画开始，动画结束，动画取消)