1、布局统一用LinearLayout通过比重控制布局大小；

2、适配器对item布局进行手动设置大小；

3、对话框手动设置外框大小；

4、文字一律需要手动设置大小；

5、19以下统一全屏，19或以上统一使用沉浸式

/**
 * 宽度适配
 * @param width 设计图宽度，如1280
 * @return 宽度缩放比例
 */
public static float getWidthSizeScale(Activity activity, float width) {
    DisplayMetrics metric = new DisplayMetrics();
    activity.getWindowManager().getDefaultDisplay().getMetrics(metric);
    float screenWidth = metric.widthPixels;  // 屏幕宽度（像素）
    if (metric.heightPixels > screenWidth) {
        screenWidth = getHasVirtualKey(activity);
    }
    return screenWidth / width;
}

/**
 * 高度适配
 * @param height 设计图高度：如800
 * @return 高度缩放比例
 */
public static float getHeightSizeScale(Activity activity, float height) {
    DisplayMetrics metric = new DisplayMetrics();
    activity.getWindowManager().getDefaultDisplay().getMetrics(metric);
    float screenWidth = metric.widthPixels;  // 屏幕宽度（像素）
    float screenHeight = getHasVirtualKey(activity);
    if (metric.heightPixels > screenWidth) {
        screenHeight = metric.widthPixels;
    }
    return screenHeight / height;
}

/**
 * 通过反射，获取包含虚拟键的整体屏幕高度
 */
private static int getHasVirtualKey(Activity activity) {
    int dpi = 0;
    Display display = activity.getWindowManager().getDefaultDisplay();
    DisplayMetrics dm = new DisplayMetrics();
    @SuppressWarnings("rawtypes")
    Class c;
    try {
        c = Class.forName("android.view.Display");
        @SuppressWarnings("unchecked")
        Method method = c.getMethod("getRealMetrics", DisplayMetrics.class);
        method.invoke(display, dm);
        dpi = dm.heightPixels;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return dpi;
}

/**
 * 文字适配
 */
public static float getTextScale(Activity activity) {
    DisplayMetrics metric = new DisplayMetrics();
    activity.getWindowManager().getDefaultDisplay().getMetrics(metric);
    float widthPixels = metric.widthPixels;
    float densityDpi = metric.densityDpi;
    if (metric.heightPixels > widthPixels) {
        widthPixels = metric.heightPixels;
    }
    return widthPixels / densityDpi / 5;
}

沉浸式设置

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    
    // 沉浸式退出监听
    getWindow().getDecorView().setOnSystemUiVisibilityChangeListener(
            new View.OnSystemUiVisibilityChangeListener() {
        @Override
        public void onSystemUiVisibilityChange(int visibility) {
            initWindow();
        }
    });
}

@Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    if(hasFocus){
        initWindow();
    }
}

private void initWindow() {
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        getWindow().getDecorView().setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
        );
    }
}