android图片渐变更画效果

        AlphaAnimation alpha=new AlphaAnimation(0.0f,0.1f);
        alpha.setDuration(3000);//动画效果时间3秒
        logoImg.setAnimation(alpha);
        alpha.setAnimationListener(new AnimationListener() {
			
			@Override//动画效果前执行
			public void onAnimationStart(Animation animation) {
				// TODO Auto-generated method stub
				
			}
			
			@Override//动画效果中执行
			public void onAnimationRepeat(Animation animation) {
				// TODO Auto-generated method stub
				
			}
			
			@Override//动画效果后执行
			public void onAnimationEnd(Animation animation) {
				// TODO Auto-generated method stub
				Intent intent=new Intent(LogoActivity.this,LoginActivity.class);
				startActivity(intent);
			}
		});