I also tried exporting without alpha it did not work for me but I figured it out that why I was getting error. I create an AppIcon using Figma & Sketch, but I tried to make a 2D geometry shape to 3D viewable. So I assume that I can achieve it by using some shadows & the same geometry but with lower alpha-like %70. After that, I got the AppIcon and export it without Alpha ticking but the problem was the main source of the image includes a container with lower alpha-like I did. So I change it to another graphical shape without alpha and it worked.

错误信息本身是这样的:

“无效的应用商店图标。在资产目录中的应用程序商店图标 “YourApp。应用不能透明，也不能包含alpha通道。”

所有应用程序图标必须是方形的，不透明或半透明(alpha值!= 1.0)。

提示:应用程序图标可能有圆角。(在这里分享你的应用程序图标)

以下是苹果应用程序图标-人机界面指南

I also tried exporting without alpha it did not work for me but I figured it out that why I was getting error. I create an AppIcon using Figma & Sketch, but I tried to make a 2D geometry shape to 3D viewable. So I assume that I can achieve it by using some shadows & the same geometry but with lower alpha-like %70. After that, I got the AppIcon and export it without Alpha ticking but the problem was the main source of the image includes a container with lower alpha-like I did. So I change it to another graphical shape without alpha and it worked.

我可以通过复制文件来解决Mac Sierra OS的问题，将新文件拖到桌面上，在预览中打开，然后单击导出选项(在文件菜单中)，然后出现不带“alpha”的保存选项

如果你没有mac，在windows上你可以打开Paint并保存为正确尺寸1024x1024的PNG

将图标从。png格式改为。jpg格式，一切都很顺利。