适配iPhoneX、iPhoneXs、iPhoneXs Max、

1. 先来认识px与pt区别
   px就是表示pixel像素，是屏幕上显示数据的最基本的点，它不是自然界的长度单位，点的大小是会变的，也称为相对长度；
   pt就是point，是印刷行业常用单位磅，等于1/72英寸，所以它是一个自然界标准的长度单位，也称为绝对长度。

2. 我们再来了解缩放因子(scale factor between logic point and device pixel)
   早期的iPhone3GS的屏幕分辨率是320*480(PPI=163)，iOS绘制图形(CGPoint/CGSize/CGRect)均以point为单位：1 point = 1 pixel
   后来在iPhone4中，同样大小3.5 inch的屏幕采用了Retina显示技术，横、纵向方向像素密度都被放大到2倍，像素分辨率提高到(320x2)x(480x2)= 960x640(PPI=326)显像分辨率提升至iPhone3GS的4倍（1个Point被渲染成1个2x2的像素矩阵）
   但是对于开发者来说，iOS绘制图形的API依然沿袭point为单位。在同样的逻辑坐标系下：1 point = scale*pixel（在iPhone4~6中，缩放因子scale=2；在iPhone6+中，缩放因子scale=3）

3. iPhone 各种机型尺寸信息列表入下表：

需要注意的地方是6(S)+／7+／8+的时候，实际的缩放因子并不等于逻辑上的缩放因子。所以，他的屏幕分辨率是1080x1920而不是1242x2208
上述数据，可以通过代码获取逻辑缩放因子、逻辑屏幕宽度；实际缩放/物理因子、实际/物理屏幕宽度：

//逻辑缩放因子
[UIScreen mainScreen].scale
//逻辑屏幕宽度
[UIScreen mainScreen].bounds
 
//实际/物理缩放因子
[UIScreen mainScreen].nativeScale
//实际/物理屏幕宽度
[UIScreen mainScreen].nativeBounds

4. 适配常用宏

//获得屏幕的宽高
#define kScreenWidth [UIScreen mainScreen].bounds.size.width
#define kScreenHeight [UIScreen mainScreen].bounds.size.height
//iPhoneX / iPhoneXS
#define  isIphoneX_XS     kScreenWidth == 375.f && kScreenHeight == 812.f ? YES : NO
//iPhoneXR / iPhoneXSMax
#define  isIphoneXR_XSMax    kScreenWidth == 414.f && kScreenHeight == 896.f ? YES : NO
//异性全面屏
#define   isFullScreen    isIphoneX_XS || isIphoneXR_XSMax

// Status bar height.
#define  StatusBarHeight     isFullScreen ? 44.f : 20.f

// Navigation bar height.
#define  NavigationBarHeight  44.f

// Tabbar height.
#define  TabbarHeight         isFullScreen ? (49.f+34.f) : 49.f

// Tabbar safe bottom margin.
#define  TabbarSafeBottomMargin         isFullScreen ? 34.f : 0.f

// Status bar & navigation bar height.
#define  StatusBarAndNavigationBarHeight  isFullScreen ? 88.f : 64.f

5. 获取安全区域

+ (CGRect)GetSafeAreaImpl{
    UIView *view = UIApplication.sharedApplication.windows.lastObject;
//    UIView *view = (UIView *)GetAppController().unityView;
    CGRect area = [self CustomComputeSafeArea:view];
    //    x = area.origin.x;
    //    y = area.origin.y;
    //    w = area.size.width;
    //    h = area.size.height;
    return area;
}

+ (CGRect)CustomComputeSafeArea:(UIView *)view{
    CGSize screenSize = view.bounds.size;
    CGRect screenRect = CGRectMake(0, 0, screenSize.width, screenSize.height);
    
    UIEdgeInsets insets = UIEdgeInsetsMake(0, 0, 0, 0);
    if (@available(iOS 11.0, *)) {
        insets = [view safeAreaInsets];
    }
    screenRect.origin.x = screenRect.origin.x + insets.left;
    screenRect.origin.y = screenRect.origin.y + insets.top;
//    screenRect.size.width -= insets.left + insets.right;
    screenRect.size.width = screenRect.size.width - (insets.left + insets.right);
    screenRect.size.height = screenRect.size.height - (insets.top + insets.bottom);
    // 乘以缩放因子，根据需求可以省略
    float scale = view.contentScaleFactor;
    screenRect.origin.x = screenRect.origin.x * scale;
    screenRect.origin.y = screenRect.origin.y * scale;
    screenRect.size.width = screenRect.size.width * scale;
    screenRect.size.height = screenRect.size.height * scale;
    return screenRect;
}

6. 启动图数据

   
   

7. 有刘海机型安全区域，有无刘海机型开发尺寸对比图

   
   刘海机型安全区域
   刘海机型开发尺寸
   非刘海机型开发尺寸