1)iPhone X screenshot support in iTunes Connect.October 27, 2017.

 2)You can now upload screenshots for iPhone X. 
  You’ll see a new tab for 5.8-inch displays under Screenshots and App Previews on your iOS app  version information page.

 3)Note that iPhone X screenshots are optional and cannot be used for smaller devices sizes. 
  5.5-inchdisplay screenshots are still required for all apps that run on iPhone.

 4)iPhone X Screenshot Resolutions
  1125 by 2436 (Portrait)
  2436 by 1125 (Landscape)

现在苹果公司通过iTunesconnect增加了一款新设备iPad Pro的屏幕截图。以下是itunesconnections所需的各种尺寸的屏幕截图。

iPhone 6 Plus(5.5英寸)- 2208x1242 iPhone 6(4.7英寸)- 1334x750 iPhone 5/5s(4英寸)- 1136x640 iPhone 4s(3.5英寸)- 960x640 iPad - 1024x768 iPadPro - 2732x2048

为了获得适当大小的屏幕截图，而无需手动创建它们——在最新版本的Xcode中运行你的应用，并选择你需要截图的iPhone，然后在查看模拟器时点击cmd-s。这将保存一个完整分辨率的截图到你的桌面，你需要提交。

正如下面@HoffZ所指出的，确保比例设置为100%。

在Xcode中选择模拟器:

在模拟器菜单中将比例设置为100%:

按cmd-s保存:

iTunes connect可接受以下分辨率:

iPhone 3+4 (3.5 Inch) 640 x 960 iPhone 5, iPhone 5S, iPhone 5C (4 Inch) 640 x 1136 iPhone 6, iPhone 6S, iPhone 7, iPhone 8 (4.7 Inch) 750 x 1334 iPhone 6 Plus, iPhone 6S Plus, iPhone 7 Plus, iPhone 8 Plus (5.5 Inch) 1242 x 2208 You need the screenshot in this resolution, the phone scales them down to 1080 x 1920 iPhone X (5.8 Inch) 1125 x 2436 iPhone XR (6.1 Inch) 828 x 1792 iPhone XS (5.8 Inch) 1125 x 2436 iPhone XS Max (6.5 Inch) 1242 x 2688 iPad Mini 2, iPad Mini 3, iPad Mini 4 (7.9 Inch) 1536 x 2048 iPad 3, iPad 4, iPad Pro, iPad Air, iPad Air 2 (9.7 Inch) 1536 x 2048 iPad Pro (10.5 Inch) 1668 x 2224 iPad Pro (12.9 Inch) 2048 x 2732 Apple Watch Series 1, Apple Watch Series 2, Apple Watch Series 3 - 38mm (1.5 Inch) 272 x 340 Apple Watch Series 4 - 40mm (1.57 Inch) 394 x 324 Apple Watch Series 1, Apple Watch Series 2, Apple Watch Series 3 - 42mm (1.65 Inch) 312 x 390 Apple Watch Series 4 - 44mm (1.78 Inch) 448 x 368

甚至苹果关于此事的文件也不完整。

更新:苹果公司推出了一个新的媒体管理器，它只需要你为最大的iPhone和/或iPad设备创建艺术品。将为您创建较小的图像。请注意，如果您以前没有创建iPad Pro图像，那么现在必须创建(如果您支持iPad)。

更新:现在支持新设备的截图和应用程序预览。

(在这里交叉发布我的答案:https://stackoverflow.com/a/25775147/798533)

对于任何想要上传图像分辨率的人(如果你想创建一些花哨的photoshop截图)，它们是:

iPhone 6: 750 × 1334 iPhone 6 Plus: 1242 × 2208

这里有很好的参考指南:http://www.paintcodeapp.com/news/iphone-6-screens-demystified(谈论iPhone 6+的分辨率和下采样)。

这些细节由日志给出…

iPhone 6 Plus

Screen bounds: {{0, 0}, {414, 736}}, Screen resolution: <UIScreen: 0x7f97fad330b0; bounds = {{0, 0}, {414, 736}}; 
mode = <UIScreenMode: 0x7f97fae1ce00; size = 1242.000000 x 2208.000000>>, scale: 3.000000, nativeScale: 3.000000

iPhone 6

Screen bounds: {{0, 0}, {375, 667}}, Screen resolution: <UIScreen: 0x7fa01b5182d0; bounds = {{0, 0}, {375, 667}}; 
mode = <UIScreenMode: 0x7fa01b711760; size = 750.000000 x 1334.000000>>, scale: 2.000000, nativeScale: 2.000000