android动画问题，XML写闪烁，动态代码写为什么不闪烁？

animationSet1 = new AnimationSet(true);
 animationSet2 = new AnimationSet(true);
 image2.setVisibility(View.VISIBLE);
 Animation animation1 = AnimationUtils.loadAnimation(getActivity(), R.anim.tttxt_fragment_layout_imageview1_anim);
 animationSet1.addAnimation(animation1);
 Animation animation2 = AnimationUtils.loadAnimation(getActivity(), R.anim.tttxt_fragment_layout_imageview2_anim);
 animationSet2.addAnimation(animation2);
 image1.startAnimation(animationSet1);
 image2.startAnimation(animationSet2);
 tttxt_fragment_layout_imageview1_anim：


 android:duration="2000"
 android:fillAfter="true"
 android:fromXDelta="0%"
 android:toXDelta="-100%" />

 tttxt_fragment_layout_imageview2_anim：

 android:duration="2000"
 android:fillAfter="true"
 android:fromXDelta="100%"
 android:toXDelta="0%" />

上面这种方法加载动画为什么闪烁？

下面这样就不闪烁，这不是一样吗？：

 AnimationSet animationSet1 = new AnimationSet(true);
 AnimationSet animationSet2 = new AnimationSet(true);
 image2.setVisibility(View.VISIBLE);
 TranslateAnimation ta = new TranslateAnimation(
 Animation.RELATIVE_TO_SELF, 0f, Animation.RELATIVE_TO_SELF,
 -1f, Animation.RELATIVE_TO_SELF, 0f,
 Animation.RELATIVE_TO_SELF, 0f);
 ta.setDuration(2000);
 animationSet1.addAnimation(ta);
 animationSet1.setFillAfter(true);
 ta = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 1.0f,
 Animation.RELATIVE_TO_SELF, 0f, Animation.RELATIVE_TO_SELF,
 0f, Animation.RELATIVE_TO_SELF, 0f);
 ta.setDuration(2000);
 animationSet2.addAnimation(ta);
 animationSet2.setFillAfter(true);
 //iamgeView 出去 imageView2 进来
 image1.startAnimation(animationSet1);
 image2.startAnimation(animationSet2);