PopupWindow的简单用法

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#e96f6f"
    android:gravity="center"
    android:orientation="vertical">
 
    <TextView
        android:id="@+id/popwindow_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="弹出窗的标题" />
 
    <TextView
        android:id="@+id/popwindow_content"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="弹出窗的内容" />
</LinearLayout>

btnShowWindow.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //实例化弹窗布局
                View contentView = LayoutInflater.from(MainActivity.this).inflate(R.layout.layout_popupwindow, null);
                //传入弹窗布局和宽高，创建popupwindow对象,
                PopupWindow popupWindow = new PopupWindow(contentView, ViewGroup.LayoutParams.MATCH_PARENT, 500, true);
                //显示在按钮下面
                popupWindow.showAsDropDown(view, 100, 100);
            }
        });

popupWindow.showAtLocation(view, Gravity.BOTTOM, 0, 0);

        //获取按钮的x和y坐标
        int[] location = new int[2];
        view.getLocationOnScreen(location);
        //弹窗的x轴不变，y轴减去弹窗自身的高度，刚好就在按钮上面了
        popupWindow.showAtLocation(view, Gravity.NO_GRAVITY, location[0], location[1] - popupWindow.getHeight());

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate
        android:duration="300"
        android:fromYDelta="100%"
        android:toYDelta="0" />
    <alpha
        android:duration="300"
        android:fromAlpha="0.0"
        android:toAlpha="1.0" />
</set>

    <style name="window_anim_in">
        <!--显示布局的动画-->
        <item name="android:windowEnterAnimation">@anim/anim_in</item>
    </style>

popupWindow.setAnimationStyle(R.style.window_anim_in);