// 用于PopupWindow的View
 View contentView=LayoutInflater.from(context).inflate(layoutRes, null, false);
 // 创建PopupWindow对象，其中：
 // 第一个参数是用于PopupWindow中的View，第二个参数是PopupWindow的宽度，
 // 第三个参数是PopupWindow的高度，第四个参数指定PopupWindow能否获得焦点
 PopupWindow window=new PopupWindow(contentView, 100, 100, true);
 // 设置PopupWindow的背景
 window.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
 // 设置PopupWindow是否能响应外部点击事件
 window.setOutsideTouchable(true);
 // 设置PopupWindow是否能响应点击事件
 window.setTouchable(true);
 // 显示PopupWindow，其中：
 // 第一个参数是PopupWindow的锚点，第二和第三个参数分别是PopupWindow相对锚点的x、y偏移
 window.showAsDropDown(anchor, xoff, yoff);
 // 或者也可以调用此方法显示PopupWindow，其中：
 // 第一个参数是PopupWindow的父View，第二个参数是PopupWindow相对父View的位置，
 // 第三和第四个参数分别是PopupWindow相对父View的x、y偏移
 // window.showAtLocation(parent, gravity, x, y);

window.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
window.setOutsideTouchable(true);

public abstract class CommonPopupWindow {
 protected Context context;
 protected View contentView;
 protected PopupWindow mInstance;

 public CommonPopupWindow(Context c, int layoutRes, int w, int h) {
  context=c;
  contentView=LayoutInflater.from(c).inflate(layoutRes, null, false);
  initView();
  initEvent();
  mInstance=new PopupWindow(contentView, w, h, true);
  initWindow();
 }

 public View getContentView() { return contentView; }
 public PopupWindow getPopupWindow() { return mInstance; }

 protected abstract void initView();
 protected abstract void initEvent();

 protected void initWindow() {
  mInstance.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
  mInstance.setOutsideTouchable(true);
  mInstance.setTouchable(true);
 }

 public void showBashOfAnchor(View anchor, LayoutGravity layoutGravity, int xmerge, int ymerge) {
  int[] offset=layoutGravity.getOffset(anchor, mInstance);
  mInstance.showAsDropDown(anchor, offset[0]+xmerge, offset[1]+ymerge);
 }

 public void showAsDropDown(View anchor, int xoff, int yoff) {
  mInstance.showAsDropDown(anchor, xoff, yoff);
 }

 public void showAtLocation(View parent, int gravity, int x, int y) {
  mInstance.showAtLocation(parent, gravity, x, y);
 }
}

public static class LayoutGravity {
 private int layoutGravity;
 // waring, don't change the order of these constants!
 public static final int ALIGN_LEFT=0x1;
 public static final int ALIGN_ABOVE=0x2;
 public static final int ALIGN_RIGHT=0x4;
 public static final int ALIGN_BOTTOM=0x8;
 public static final int TO_LEFT=0x10;
 public static final int TO_ABOVE=0x20;
 public static final int TO_RIGHT=0x40;
 public static final int TO_BOTTOM=0x80;
 public static final int CENTER_HORI=0x100;
 public static final int CENTER_VERT=0x200;

 public LayoutGravity(int gravity) {
  layoutGravity=gravity;
 }

 public int getLayoutGravity() { return layoutGravity; }
 public void setLayoutGravity(int gravity) { layoutGravity=gravity; }

 public void setHoriGravity(int gravity) {
  layoutGravity&=(0x2+0x8+0x20+0x80+0x200);
  layoutGravity|=gravity;
 }
 public void setVertGravity(int gravity) {
  layoutGravity&=(0x1+0x4+0x10+0x40+0x100);
  layoutGravity|=gravity;
 }

 public boolean isParamFit(int param) {
  return (layoutGravity & param) > 0;
 }

 public int getHoriParam() {
  for(int i=0x1; i<=0x100; i=i<<2)
   if(isParamFit(i))
    return i;
  return ALIGN_LEFT;
 }

 public int getVertParam() {
  for(int i=0x2; i<=0x200; i=i<<2)
   if(isParamFit(i))
    return i;
  return TO_BOTTOM;
 }

 public int[] getOffset(View anchor, PopupWindow window) {
  int anchWidth=anchor.getWidth();
  int anchHeight=anchor.getHeight();

  int winWidth=window.getWidth();
  int winHeight=window.getHeight();
  View view=window.getContentView();
  if(winWidth<=0)
   winWidth=view.getWidth();
  if(winHeight<=0)
   winHeight=view.getHeight();

  int xoff=0;
  int yoff=0;

  switch (getHoriParam()) {
   case ALIGN_LEFT:
    xoff=0; break;
   case ALIGN_RIGHT:
    xoff=anchWidth-winWidth; break;
   case TO_LEFT:
    xoff=-winWidth; break;
   case TO_RIGHT:
    xoff=anchWidth; break;
   case CENTER_HORI:
    xoff=(anchWidth-winWidth)/2; break;
   default:break;
  }
  switch (getVertParam()) {
   case ALIGN_ABOVE:
    yoff=-anchHeight; break;
   case ALIGN_BOTTOM:
    yoff=-winHeight; break;
   case TO_ABOVE:
    yoff=-anchHeight-winHeight; break;
   case TO_BOTTOM:
    yoff=0; break;
   case CENTER_VERT:
    yoff=(-winHeight-anchHeight)/2; break;
   default:break;
  }
  return new int[]{ xoff, yoff };
 }
}

<!-- res/anim/translate_in.xml -->
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
 <translate
  android:fromXDelta="0"
  android:toXDelta="0"
  android:fromYDelta="100%"
  android:toYDelta="0"
  android:duration="200" >
 </translate>
</set> 

<!-- res/anim/translate_out.xml -->
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
 <translate
  android:fromXDelta="0"
  android:toXDelta="0"
  android:fromYDelta="0"
  android:toYDelta="100%"
  android:duration="200" >
 </translate>
</set>

<!-- res/values/styles.xml -->
 <style name="animTranslate">
  <item name="android:windowEnterAnimation">@anim/translate_in</item>
  <item name="android:windowExitAnimation">@anim/translate_out</item>
</style>

window.setAnimationStyle(R.style.animTranslate);

window.setOnDismissListener(new PopupWindow.OnDismissListener() {
  @Override
  public void onDismiss() {
   WindowManager.LayoutParams lp=getWindow().getAttributes();
   lp.alpha=1.0f;
   getWindow().clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
   getWindow().setAttributes(lp);
  }
 });

 window.showAtLocation(activityPopup, Gravity.BOTTOM, 0, 0);
 WindowManager.LayoutParams lp=getWindow().getAttributes();
 lp.alpha=0.3f;
 getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
 getWindow().setAttributes(lp);