現在專案中要實現導航欄（標題欄）下顯示一個下拉選單，從上往下的平移動畫。原生PopupWindow的setAnimationStyle設定的動畫都是從螢幕外面滑入螢幕內的動畫效果，選單顯示動畫過程中會發現是從導航欄上面滑過的，達不到我們要的效果。只好自己想辦法實現這個動畫效果了，然後花了點時間簡單封裝了一個。完整原始碼貼在下面，比較簡單，所以不多做解釋了。有問題也希望大家指出，主要是為了穩定和方便使用。 原始碼： package com.android.myapplication; import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Handler;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.FrameLayout; /**
 * Author: zls.
 * Created on 2016/4/22 21:02.
 */
public class PopupWindow {     private static Handler handler;
    private static xWindow popupWindow;
    private static long DURATION = 0;     public static void showAtLocation(Context context, View v, int x, int y){
        showAtLocation(context, v, x, y, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    }     public static void showAtLocation(Context context, View v, int x, int y, int[] anim){
        int enterAnim = 0, exitAnim = 0;
        if(anim.length > 0) enterAnim = anim[0];
        if(anim.length > 1) exitAnim = anim[1];
        showAtLocation(context, v, x, y, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, enterAnim, exitAnim);
    }     public static void showAtLocation(Context context, View v, int x, int y, int width, int height){
        showAtLocation(context, v, x, y, width, height, 0, 0);
    }     public static void showAtLocation(Context context, View v, int x, int y, int width, int height, int enterAnim, int exitAnim){
        if(context == null || !(context instanceof Activity) || null == v) return;
        close();
        initView(context, v, width, height, enterAnim, exitAnim);
        popupWindow.showAtLocation(v, 0, x, y);
    }     public static void showAsDropDown(Context context, View anchor, final View v){
        showAsDropDown(context, anchor, v, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    }     public static void showAsDropDown(Context context, View anchor, View v, int[] anim){
        int enterAnim = 0, exitAnim = 0;
        if(anim.length > 0) enterAnim = anim[0];
        if(anim.length > 1) exitAnim = anim[1];
        showAsDropDown(context, anchor, v, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, enterAnim, exitAnim);
    }     public static void showAsDropDown(Context context, View anchor, View v, int width, int height){
        showAsDropDown(context, anchor, v, width, height, 0, 0);
    }     public static void showAsDropDown(Context context, View anchor, View v, int width, int height, int enterAnim, int exitAnim){
        if(context == null || !(context instanceof Activity) || null == v) return;
        close();
        initView(context, v, width, height, enterAnim, exitAnim);
        popupWindow.showAsDropDown(anchor);
    }     private static void initView(Context context, final View v, int width, int height, int enterAnim, int exitAnim){
        FrameLayout frame = new FrameLayout(context);
        frame.addView(v);
        popupWindow = new xWindow(frame, width, height);
        popupWindow.setFocusable(true);
        popupWindow.setTouchable(true);
        popupWindow.setOutsideTouchable(true);
        popupWindow.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#00000000")));         DURATION = 0;
        if(exitAnim > 0) {
            final Animation exitAnimation = AnimationUtils.loadAnimation(context, exitAnim);
            DURATION = exitAnimation.getDuration();
            popupWindow.setOnPreDismissListener(new Runnable() {
                @Override
                public void run() {
                    v.startAnimation(exitAnimation);
                }
            });
        }
        if(enterAnim > 0) {
            Animation animation = AnimationUtils.loadAnimation(context, enterAnim);
            v.startAnimation(animation);
        }
        handler = new Handler(context.getMainLooper());
    }     public static void close(){
        if(popupWindow != null){
            popupWindow.dismiss();
            popupWindow = null;
            handler = null;
        }
    }     private static class xWindow extends android.widget.PopupWindow{         private Runnable onPreDismissListener;         public xWindow(View v, int w, int h){
            super(v, w, h);
        }         @Override
        public void dismiss() {
            if(null != onPreDismissListener){
                onPreDismissListener.run();
            }
            handler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    xWindow.super.dismiss();
                }
            }, DURATION);
        }         public void setOnPreDismissListener(Runnable onPreDismissListener) {
            this.onPreDismissListener = onPreDismissListener;
        }
    } } PS：第一篇博文，正在加班，沒辦法花很多時間來寫了，畢竟也比較簡單。因為在網上找不到相關的文章，所以只好通過自己的辦法去實現了，希望可以幫到一些剛入門的朋友。