Android PopupWindow，居中显示，按屏幕比例调整大小，在某个控件的定点位置等

先上图：

完整代码：

 PopupWindow pop;

    private void popwindow() {
        if (pop != null && pop.isShowing()) {
            pop.dismiss();
        }
        pop = new PopupWindow(getContext());
        View popView = LayoutInflater.from(getContext()).inflate(R.layout.pop_power, null, false);
        ImageView iv_cancel = popView.findViewById(R.id.iv_cancel);
        popView.findViewById(R.id.iv_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                pop.dismiss();
            }
        });
        popView.findViewById(R.id.tv_friend_see).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                presenter.video_secret(mVideoAdapter.getDataList().get(sharePostion).getCommunity_id(), 1);
                pop.dismiss();
            }
        });
        popView.findViewById(R.id.tv_self_see).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                presenter.video_secret(mVideoAdapter.getDataList().get(sharePostion).getCommunity_id(), 2);
                pop.dismiss();
            }
        });
        pop.setContentView(popView);
        int width = ScreenUtils.getWidth(context);
        pop.setWidth(width * 3 / 4);
        // pop.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
        pop.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
        pop.setBackgroundDrawable(new ColorDrawable());
        pop.setFocusable(true);
        pop.setOutsideTouchable(true);
        //居中显示，第一个参数的控件只要是这个popwindow里面的随便一个控件就行
        pop.showAtLocation(iv_cancel, Gravity.CENTER, 0, 0);
        //根据控件定点显示，后面的两个参数是偏移量
            // pop.showAsDropDown(iv_cancel, 0, 0);
        }

布局：

<?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="wrap_content"
    android:layout_gravity="center"
    android:layout_marginLeft="28dp"
    android:layout_marginRight="28dp"
    android:background="@drawable/bg_white_solid"
    android:minHeight="200dp"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/iv_cancel"
        android:layout_width="22dp"
        android:layout_height="22dp"
        android:layout_gravity="right"
        android:layout_marginTop="15dp"
        android:layout_marginRight="15dp"
        android:padding="5dp"
        android:src="@drawable/but_guanb" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="30dp"
        android:layout_marginBottom="20dp"
        android:text="设置为"
        android:textColor="@color/color_33"
        android:textSize="22sp" />

    <TextView
        android:id="@+id/tv_friend_see"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="25dp"
        android:layout_marginBottom="15dp"
        android:paddingLeft="5dp"
        android:paddingBottom="5dp"
        android:text="设为好友可见"
        android:textColor="@color/color_33"
        android:textSize="17sp" />

    <TextView
        android:id="@+id/tv_self_see"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="25dp"
        android:layout_marginBottom="15dp"
        android:paddingLeft="5dp"
        android:paddingBottom="5dp"
        android:text="设为私密"
        android:textColor="@color/color_33"
        android:textSize="17sp" />
</LinearLayout>

布局中的背景bg_white_solid.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="@color/white" />
    <corners android:radius="20dp" />
    <!--    <stroke
            android:width="1dp"
            android:color="@color/color_main" />-->
</shape>

获取屏幕宽度的ScreenUtils.java:

package com.aliyun.video.common.utils;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Point;
import android.os.Build;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.WindowManager;

/**
 * @author cross_ly
 * @date 2018/11/28
 * <p>描述:获取当前设备的屏幕参数
 *
 */
public class ScreenUtils {

    /**
     * 获取屏幕的宽高 单位px
     * x = width
     * y = height
     * @param context Context
     * @return Point
     */
    public static Point getScreenPoint(Context context) {

        Point screenPoint = new Point();
        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        screenPoint.x = displayMetrics.widthPixels;
        screenPoint.y = displayMetrics.heightPixels;
        return screenPoint;
    }

    /**
     * 获取屏幕宽
     *
     * @param context 上下文
     * @return int ，单位px
     */
    public static int getWidth(Context context) {

        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        return displayMetrics.widthPixels;
    }

    /**
     * 获取屏幕高
     *
     * @param context 上下文
     * @return int ，单位px
     */
    public static int getHeight(Context context) {

        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        return displayMetrics.heightPixels;
    }

    /**
     * 获取屏幕的真实高度，包含导航栏、状态栏
     * @param context 上下文
     * @return int,单位px
     */
    public static int getRealHeight(Context context) {
        WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Display display = windowManager.getDefaultDisplay();
        DisplayMetrics dm = new DisplayMetrics();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            display.getRealMetrics(dm);
        } else {
            display.getMetrics(dm);
        }
        return dm.heightPixels;
    }

    /**
     * 获取屏幕的真实高度，包含导航栏、状态栏
     * @param context 上下文
     * @return int,单位px
     */
    public static int getRealWidth(Context context) {
        WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Display display = windowManager.getDefaultDisplay();
        DisplayMetrics dm = new DisplayMetrics();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            display.getRealMetrics(dm);
        } else {
            display.getMetrics(dm);
        }
        return dm.widthPixels;
    }
    /**
     * 是否在屏幕右侧
     *
     * @param mContext 上下文
     * @param xPos     位置的x坐标值
     * @return true：是。
     */
    public static boolean isInRight(Context mContext, int xPos) {
        return (xPos > getWidth(mContext) / 2);
    }

    /**
     * 是否在屏幕左侧
     *
     * @param mContext 上下文
     * @param xPos     位置的x坐标值
     * @return true：是。
     */
    public static boolean isInLeft(Context mContext, int xPos) {
        return (xPos < getWidth(mContext) / 2);
    }

    /**
     * 获取虚拟导航栏高度
     * @param activity 上下文
     * @return int,单位px
     */
    public static int getNavigationHeight(Context activity) {
        if (activity == null) {
            return 0;
        }
        Resources resources = activity.getResources();
        int resourceId = resources.getIdentifier("navigation_bar_height",
                         "dimen", "android");
        int height = 0;
        if (resourceId > 0) {
            //获取NavigationBar的高度
            height = resources.getDimensionPixelSize(resourceId);
        }
        return height;
    }
}