Android抛物线下载动画制作过程

下载动画经常出现在下载需求多的app中，比如游戏下载平台，应用市场……

先看看效果图：

实现

private void startAnim() {  
 //以bitmap创建new ImageView
 iv.setDrawingCacheEnabled(true);
 Bitmap bitmap = iv.getDrawingCache();  
 ImageView logo = new ImageView(this);  
 logo.setScaleType(ImageView.ScaleType.FIT_XY);  
 logo.setImageBitmap(bitmap);
 int[] startLocation = new int[2];  
 iv.getLocationInWindow(startLocation);  
 end.getLocationInWindow(location_download);
 setAnim(logo, startLocation, location_download);
}

设置动画

private void setAnim(final ImageView logo, int[] startLocation,int[] location_download) {  
ViewGroup animMaskLayout = createAnimLayout();  
animMaskLayout.addView(logo);// 把动画小球添加到动画层
// 计算位移
final View view = addViewToAnimLayout(logo, startLocation);
// 动画位移的X坐标  
int endY = location_download[1] - startLocation[1];
// 动画位移的y坐标  
TranslateAnimation translateAnimationX = new TranslateAnimation(0,  endX, 0, 0);  
translateAnimationX.setInterpolator(new LinearInterpolator());  
translateAnimationX.setRepeatCount(0);// 动画重复执行的次数  
translateAnimationX.setFillAfter(true);  TranslateAnimation
translateAnimationY = new TranslateAnimation(0, 0, 0, endY);  
translateAnimationY.setInterpolator(new AccelerateInterpolator());  
translateAnimationY.setRepeatCount(0);// 动画重复执行的次数  
translateAnimationX.setFillAfter(true);  AnimationSet set = new
AnimationSet(false);
set.setFillAfter(false);  
set.addAnimation(translateAnimationY);  
set.addAnimation(translateAnimationX);
set.setDuration(2000);// 动画的执行时间  
view.startAnimation(set);  // 动画监听事件  
set.setAnimationListener(new Animation.AnimationListener() {  
   // 动画的开始    
   @Override  
   public void onAnimationStart(Animation animation) {  
      logo.setVisibility(View.VISIBLE);  
  }    
  @Override
  public void onAnimationRepeat(Animation animation) {  
  }  
  // 动画的结束    
  @Override  
  public void onAnimationEnd(Animation animation) {      
      logo.setVisibility(View.GONE);  
  }
 });
}

创建动画父布局

private ViewGroup createAnimLayout() {
 ViewGroup rootView = (ViewGroup) getWindow().getDecorView();    
 LinearLayout animLayout = new LinearLayout(this);    
 LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
   LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);  
 animLayout.setLayoutParams(lp);  
 animLayout.setId(Integer.MAX_VALUE);  
 animLayout.setBackgroundResource(android.R.color.transparent);  
 rootView.addView(animLayout);
 return animLayout;
}

设置动画布局参数

private static View addViewToAnimLayout(final View view, int[] location) {
int x = location[0];
int y = location[1];
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(80, 80);
lp.leftMargin = x;
lp.topMargin = y;
view.setLayoutParams(lp);
return view;
}

代码就到此结束了，看起来并不难，动手试试吧。