让 Popwindow 向上弹出

 /**
      * 获取父控件的位置y-popwindow的高度 = 应该显示的y坐标.   x这里设置为center 不刻意指定坐标  注意:控件坐标永远是 左上角坐标!
      *
      * @param parent
      */
     public void showUp(View parent) {

         int[] location = new int[2];

         parent.getLocationOnScreen(location);
         popupWindow.setFocusable(true);
         popupWindow.setOutsideTouchable(true);

         popupWindow.setAnimationStyle(R.style.AnimationPopup);
         popupWindow.showAtLocation(parent, Gravity.CENTER_HORIZONTAL
                 | Gravity.TOP, 0, location[1] - popupWindow.getHeight() + 20);

         popupWindow.update();
     }

values\style.xml:

 <resources>
 <style name="AnimationPopup">
     <item name="@android:windowEnterAnimation">@anim/appear</item>
     <item name="@android:windowExitAnimation">@anim/disappear</item>
 </style>
 </resources>

anim\appear.xml

 <?xml version="1.0" encoding="utf-8"?>
 <set xmlns:android="http://schemas.android.com/apk/res/android" >

     <scale
         android:duration="500"
         android:fromXScale="1.0"
         android:fromYScale="0.5"
         android:pivotX="0%"
         android:pivotY="100%"
         android:toXScale="1"
         android:toYScale="1" />

     <alpha
         android:duration="500"
         android:fromAlpha="0.5"
         android:interpolator="@android:anim/accelerate_interpolator"
         android:toAlpha="1.0" />

 </set>

anim\disappear.xml

 <?xml version="1.0" encoding="utf-8"?>
 <set xmlns:android="http://schemas.android.com/apk/res/android" >

     <scale
         android:duration="500"
         android:fromXScale="1.0"
         android:fromYScale="1"
         android:pivotX="0%"
         android:pivotY="100%"
         android:toXScale="1"
         android:toYScale="0.5" />

     <alpha
         android:duration="500"
         android:fromAlpha="1.0"
         android:interpolator="@android:anim/accelerate_interpolator"
         android:toAlpha="0.0" />

 </set>

点击屏幕其他部分实现使其消失的功能需要在showAtLocation方法调用前设置下面代码：

 pop.setBackgroundDrawable(new PaintDrawable());
         pop.setOutsideTouchable(true);