背景

电商项目总喜欢在特定节日展示不同的icon图标，但是为了修改图标而更新版本的话，没那个必要。
这里介绍一种不需要通过更新版本就可以动态修改APP图标的方法。

⚠️注意：该方法在iOS10.3及以上有效

实现

• 1 导入待替换的新图片，放到项目工程新文件夹中；
• 2 配置 Info.plist 文件：

<key>CFBundleIcons</key>
<dict>
    <key>CFBundleAlternateIcons</key>
    <dict>
        <key>icon1</key>
        <dict>
            <key>CFBundleIconFiles</key>
            <array>
                <string>icon1</string>
            </array>
            <key>UIPrerenderedIcon</key>
            <false/>
        </dict>
        <key>icon2</key>
        <dict>
            <key>CFBundleIconFiles</key>
            <array>
                <string>icon2</string>
            </array>
            <key>UIPrerenderedIcon</key>
            <false/>
        </dict>
    </dict>
    <key>CFBundlePrimaryIcon</key>
    <dict>
        <key>CFBundleIconFiles</key>
    <array>
        <string>AppIcon60x60</string>
    </array>
    </dict>
</dict>

• 3 通过代码替换

        if #available(iOS 10.3, *) {
            if UIApplication.shared.supportsAlternateIcons {
                print("you can change this app's icon")
            }else {
                print("you cannot change this app's icon")
                return
            }
            
            if let name = UIApplication.shared.alternateIconName {
                // CHANGE TO PRIMARY ICON  恢复默认 icon
                UIApplication.shared.setAlternateIconName(nil) { (err:Error?) in
                    print("set icon error：\(String(describing: err))")
                }
                print("the alternate icon's name is \(name)")
            }else {
                // CHANGE TO ALTERNATE ICON 指定icon图标
                UIApplication.shared.setAlternateIconName("icon1") { (err:Error?) in
                    print("set icon error：\(String(describing: err))")
                }
            }
        }

• 4 去掉更换图标时的弹框
  更换图标时会出现系统弹框，可以使用Runtime来隐藏弹框，这样方便在节日时候程序自动 无感 更改APP 的icon
  具体代码如下：

extension UIViewController {

  //通过运行时替换系统的present方法

  public class func nkReplaceSystemPresent(){

    let systemSelector = #selector(UIViewController.present(_:animated:completion:))

    let nkSelector = #selector(UIViewController.newPesent(_:animated:completion:))



    let systemMethod = class_getInstanceMethod(self, systemSelector)

    let nkNewMethod = class_getInstanceMethod(self, nkSelector)
      method_exchangeImplementations(systemMethod!, nkNewMethod!)

  }



  @objc public func newPesent(_ vcToPresent:UIViewController, animated flag:Bool, completion: (() ->Void)? = nil) {

    if vcToPresent.isKind(of:UIAlertController.self) {

      let alertController = vcToPresent as? UIAlertController

      if alertController?.title==nil && alertController?.message==nil {
        return
      }
    }

    self.newPesent(vcToPresent, animated: flag)

  }

}
 

然后在满足需求的控制器中调用即可。
方法如下:

    override func viewDidLoad() {
        super.viewDidLoad()
        DH_MyViewController.nkReplaceSystemPresent()
    }