android PopupWindow实现从底部弹出或滑出选择菜单或窗口

<LinearLayout   
    android:id="@+id/pop_layout"  
    android:layout_width="fill_parent"  
    android:layout_height="wrap_content"  
    android:gravity="center_horizontal"  
    android:orientation="vertical"  
    android:layout_alignParentBottom="true"  
     android:background="@drawable/btn_style_alert_dialog_background"  
     >  
  
      
    <Button  
        android:id="@+id/btn_take_photo"  
        android:layout_marginLeft="20dip"  
        android:layout_marginRight="20dip"  
        android:layout_marginTop="20dip"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:text="拍照"  
        android:background="@drawable/btn_style_alert_dialog_button"  
        android:textStyle="bold"  
         />  
  
    <Button  
        android:id="@+id/btn_pick_photo"  
        android:layout_marginLeft="20dip"  
        android:layout_marginRight="20dip"  
        android:layout_marginTop="5dip"   
         android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:text="从相册选择"  
         android:background="@drawable/btn_style_alert_dialog_button"  
         android:textStyle="bold"  
         />  
  
    <Button  
        android:id="@+id/btn_cancel"  
       android:layout_marginLeft="20dip"  
       android:layout_marginRight="20dip"  
       android:layout_marginTop="15dip"   
       android:layout_marginBottom="15dip"  
       android:layout_width="fill_parent"  
       android:layout_height="wrap_content"  
       android:text="取消"  
       android:background="@drawable/btn_style_alert_dialog_cancel"  
       android:textColor="#ffffff"  
       android:textStyle="bold"  
         
        />  
</LinearLayout>  

 

    import android.app.Activity;  
    import android.content.Context;  
    import android.graphics.drawable.ColorDrawable;  
    import android.view.LayoutInflater;  
    import android.view.MotionEvent;  
    import android.view.View;  
    import android.view.View.OnClickListener;  
    import android.view.View.OnTouchListener;  
    import android.view.ViewGroup.LayoutParams;  
    import android.widget.Button;  
    import android.widget.PopupWindow;  
      
    public class SelectPicPopupWindow extends PopupWindow {  
      
      
        private Button btn_take_photo, btn_pick_photo, btn_cancel;  
        private View mMenuView;  
      
        public SelectPicPopupWindow(Activity context,OnClickListener itemsOnClick) {  
            super(context);  
            LayoutInflater inflater = (LayoutInflater) context  
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);  
            mMenuView = inflater.inflate(R.layout.alert_dialog, null);  
            btn_take_photo = (Button) mMenuView.findViewById(R.id.btn_take_photo);  
            btn_pick_photo = (Button) mMenuView.findViewById(R.id.btn_pick_photo);  
            btn_cancel = (Button) mMenuView.findViewById(R.id.btn_cancel);  
            //取消按钮  
            btn_cancel.setOnClickListener(new OnClickListener() {  
      
                public void onClick(View v) {  
                    //销毁弹出框  
                    dismiss();  
                }  
            });  
            //设置按钮监听  
            btn_pick_photo.setOnClickListener(itemsOnClick);  
            btn_take_photo.setOnClickListener(itemsOnClick);  
            //设置SelectPicPopupWindow的View  
            this.setContentView(mMenuView);  
            //设置SelectPicPopupWindow弹出窗体的宽  
            this.setWidth(LayoutParams.FILL_PARENT);  
            //设置SelectPicPopupWindow弹出窗体的高  
            this.setHeight(LayoutParams.WRAP_CONTENT);  
            //设置SelectPicPopupWindow弹出窗体可点击  
            this.setFocusable(true);  
            //设置SelectPicPopupWindow弹出窗体动画效果  
            this.setAnimationStyle(R.style.AnimBottom);  
            //实例化一个ColorDrawable颜色为半透明  
            ColorDrawable dw = new ColorDrawable(0xb0000000);  
            //设置SelectPicPopupWindow弹出窗体的背景  
            this.setBackgroundDrawable(dw);  
            //mMenuView添加OnTouchListener监听判断获取触屏位置如果在选择框外面则销毁弹出框  
            mMenuView.setOnTouchListener(new OnTouchListener() {  
                  
                public boolean onTouch(View v, MotionEvent event) {  
                      
                    int height = mMenuView.findViewById(R.id.pop_layout).getTop();  
                    int y=(int) event.getY();  
                    if(event.getAction()==MotionEvent.ACTION_UP){  
                        if(y<height){  
                            dismiss();  
                        }  
                    }                 
                    return true;  
                }  
            });  
      
        }  
      
    }  

    //把文字控件添加监听，点击弹出自定义窗口  
        tv.setOnClickListener(new OnClickListener() {             
            public void onClick(View v) {  
                //实例化SelectPicPopupWindow  
                menuWindow = new SelectPicPopupWindow(MainActivity.this, itemsOnClick);  
                //显示窗口  
                menuWindow.showAtLocation(MainActivity.this.findViewById(R.id.main), Gravity.BOTTOM|Gravity.CENTER_HORIZONTAL, 0, 0); //设置layout在PopupWindow中显示的位置  
            }  
        });  
    }  
      
    //为弹出窗口实现监听类  
    private OnClickListener  itemsOnClick = new OnClickListener(){  
  
        public void onClick(View v) {  
            menuWindow.dismiss();  
            switch (v.getId()) {  
            case R.id.btn_take_photo:  
                break;  
            case R.id.btn_pick_photo:                 
                break;  
            default:  
                break;  
            }