1.實現思路。

利用popwindow的showAsDropDown方法，結合自定義background樣式。

2.java程式碼

PopupWindow searchConditionPopwindow = null;
View contentView = null;
    public void showSearchConditionPopwindow(View parent){
        if(contentView == null){
            contentView = getLayoutInflater().inflate(R.layout.search_condition_popwindow,null);
        }
        if(searchConditionPopwindow == null){
            searchConditionPopwindow = new PopupWindow(contentView,
                    parent.getLayoutParams().width, LinearLayout.LayoutParams.WRAP_CONTENT,true);
            searchConditionPopwindow.setBackgroundDrawable(getResources().getDrawable(R.drawable.search_condation_popwindow_style));
        }
        searchConditionPopwindow.showAsDropDown(parent);
}

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:top="5dp"
        >
        <shape xmlns:android="http://schemas.android.com/apk/res/android"
            android:shape="rectangle"
            >
            <corners android:radius="6dp"></corners>
            <solid android:color="#bbffffff"/>
        </shape>
    </item>

</layer-list>

4.效果實現