仿今日头条屏幕适配

import android.app.Activity;
import android.app.Application;
import android.content.ComponentCallbacks;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.support.annotation.NonNull;
import android.util.DisplayMetrics;
import android.util.Log;

/**
 * 需要在AndroidManifest application下添加
 *  
 *  360是设计稿上宽度dp值
 */
public class ScreenAdapterUtil {
    private static final String TAG = ScreenAdapterUtil.class.getName();
    private static float sNonCompatDensity;
    private static float sNonCompatScaledDensity;

    public static void setCustomDensity(@NonNull Activity activity, @NonNull final Application application) {
        final DisplayMetrics appDisplayMetrics = application.getResources().getDisplayMetrics();
        if (sNonCompatDensity == 0) {
            sNonCompatDensity = appDisplayMetrics.density;
            sNonCompatScaledDensity = appDisplayMetrics.scaledDensity;
            application.registerComponentCallbacks(new ComponentCallbacks() {
                @Override
                public void onConfigurationChanged(Configuration newConfig) {
                    if (newConfig != null && newConfig.fontScale > 0) {
                        sNonCompatScaledDensity = application.getResources().getDisplayMetrics().scaledDensity;
                    }
                }

                @Override
                public void onLowMemory() {

                }
            });
        }

        //默认dp
        float designWidth = 360;
        try {
            ApplicationInfo appInfo = application.getPackageManager().getApplicationInfo(application.getPackageName(), PackageManager.GET_META_DATA);
            designWidth = appInfo.metaData.getInt("design_width");
        } catch (Exception e) {
            Log.e(TAG,"Exception："+ e);
        }

        Log.d(TAG,"designWidth = "+designWidth);

        final float targetDensity = appDisplayMetrics.widthPixels / designWidth;
        final float targetScaledDensity = targetDensity * (sNonCompatScaledDensity /sNonCompatDensity);
        final int targetDensityDpi = (int) (160 * targetDensity);

        appDisplayMetrics.density = targetDensity;
        appDisplayMetrics.scaledDensity = targetScaledDensity;
        appDisplayMetrics.densityDpi = targetDensityDpi;

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

     setBitmapDefaultDensity(targetDensity);

    }

    /**
     * 设置 Bitmap 的默认屏幕密度
     * 由于 Bitmap 的屏幕密度是读取配置的，导致修改未被启用
     * 所有，放射方式强行修改
     *
     * @param defaultDensity 屏幕密度
     */
    private static void setBitmapDefaultDensity(float defaultDensity) {
        //获取单个变量的值
        Class clazz;
        try {
            clazz = Class.forName("android.graphics.Bitmap");
            Field field = clazz.getDeclaredField("sDefaultDensity");
            field.setAccessible(true);
            field.set(null, defaultDensity);
            field.setAccessible(false);
        } catch (ClassNotFoundException e) {
        } catch (NoSuchFieldException e) {
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
}

注：在 setContentView() 前调用

参考 今日头条技术团队