Density 屏幕简单设配（头条）

public class Density {
    private static float appDensity;
    private static float appScaledDensity;
    private static DisplayMetrics appDisplayMetrics;

    public static void setDensity(@NonNull final Application application) {
        //获取application的DisplayMetrics
        appDisplayMetrics = application.getResources().getDisplayMetrics();

        if (appDensity == 0) {
            //初始化的时候赋值
            appDensity = appDisplayMetrics.density;
            appScaledDensity = appDisplayMetrics.scaledDensity;

            //添加字体变化的监听
            application.registerComponentCallbacks(new ComponentCallbacks() {
                @Override
                public void onConfigurationChanged(Configuration newConfig) {
                    //字体改变后,将appScaledDensity重新赋值
                    if (newConfig != null && newConfig.fontScale > 0) {
                        appScaledDensity = application.getResources().getDisplayMetrics().scaledDensity;
                    }
                }

                @Override
                public void onLowMemory() {
                }
            });
        }
    }

    //此方法在BaseActivity中做初始化(如果不封装BaseActivity的话,直接用下面那个方法就好了)
    public static void setDefault(Activity activity) {
        setAppOrientation(activity, AppUtils.WIDTH);
    }

    //此方法用于在某一个Activity里面更改适配的方向
    public static void setOrientation(Activity activity, String orientation) {
        setAppOrientation(activity, orientation);
    }

    /**
     * targetDensity
     * targetScaledDensity
     * targetDensityDpi
     * 这三个参数是统一修改过后的值
     * 

     * orientation:方向值,传入width或height
     */
    private static void setAppOrientation(@Nullable Activity activity, String orientation) {

        float targetDensity;

        //获取状态栏高度
        int barHeight = AppUtils.getStatusBarHeight(activity);
        if (orientation.equals("height")) {
            targetDensity = (appDisplayMetrics.heightPixels - barHeight) / 667f;
        } else {
            targetDensity = appDisplayMetrics.widthPixels / 360f;
        }

        float targetScaledDensity = targetDensity * (appScaledDensity / appDensity);
        int targetDensityDpi = (int) (160 * targetDensity);

        /**
         *
         * 最后在这里将修改过后的值赋给系统参数
         *
         * 只修改Activity的density值
         */

        DisplayMetrics activityDisplayMetrics = activity.getResources().getDisplayMetrics();
        activityDisplayMetrics.density = targetDensity;
        activityDisplayMetrics.scaledDensity = targetScaledDensity;
        activityDisplayMetrics.densityDpi = targetDensityDpi;
    }

    public static class AppUtils {

        public final static String WIDTH = "width";

        public final static String HEIGHT = "height";

        /**
         * px转dp
         *
         * @param context The context
         * @param px      the pixel value
         * @return value in dp
         */
        public static int pxToDp(Context context, float px) {
            DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
            return (int) ((px / displayMetrics.density) + 0.5f);
        }

        /**
         * dp转px
         *
         * @param context
         * @param dp
         * @return
         */
        public static int dpToPx(Context context, float dp) {
            DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
            return (int) ((dp * displayMetrics.density) + 0.5f);
        }

        /**
         * 获取状态栏高度
         *
         * @param context
         * @return
         */
        public static int getStatusBarHeight(Context context) {
            int result = 0;
            int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen",
                    "android");
            if (resourceId > 0) {
                result = context.getResources().getDimensionPixelSize(resourceId);
            }
            return result;
        }

        /**
         * 获得屏幕高度
         *
         * @param context
         * @return
         */
        public static int getPxWidth(Context context) {
            WindowManager wm = (WindowManager) context
                    .getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics outMetrics = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(outMetrics);
            return outMetrics.widthPixels;
        }

        /**
         * 获得屏幕宽度
         *
         * @param context
         * @return
         */
        public static int getPxHeight(Context context) {
            WindowManager wm = (WindowManager) context
                    .getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics outMetrics = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(outMetrics);
            return outMetrics.heightPixels;
        }

        /**
         * 获得屏幕高度
         *
         * @param context
         * @return
         */
        public static int getDpWidth(Context context) {
            WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics dm = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(dm);
            int width = dm.widthPixels;         // 屏幕宽度（像素）
            float density = dm.density;         // 屏幕密度（0.75 / 1.0 / 1.5）
            // 屏幕宽度算法:屏幕宽度（像素）/屏幕密度
            int dpWidth = (int) (width / density);  // 屏幕宽度(dp)
            return dpWidth;
        }

        /**
         * 获得屏幕宽度
         *
         * @param context
         * @return
         */
        public static int getDpHeight(Context context) {
            WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics dm = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(dm);
            int height = dm.heightPixels;       // 屏幕高度（像素）
            float density = dm.density;         // 屏幕密度（0.75 / 1.0 / 1.5）
            // 屏幕宽度算法:屏幕宽度（像素）/屏幕密度
            int dpHeight = (int) (height / density);// 屏幕高度(dp)
            return dpHeight;
        }
    }

}