创建一个57x57 PNG文件并将其导入项目包。然后打开项目中包含的.plist文件，并编辑键Icon File的值以匹配您提供的图标的名称（ CFBundleIconFile 是实际的键，但Xcode编辑器将为您显示更好的名称。）

Create a 57x57 PNG file and import it into your project bundle. Then open the .plist file that is included in your project and edit the value for the key "Icon File" to match the name of the icon you provided (CFBundleIconFile is the actual key, but the Xcode editor will display the nicer name for you).