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我写这段代码是为了创建一个按钮，里面有一个 UIImage。
func createDrawerBarButton(image : String) {
let button = UIButton(type: .custom)
button.setImage(UIImage(named: image)?.withRenderingMode(.alwaysTemplate), for: UIControlState.normal)
button.frame = CGRect(x: 0, y: 0, width: 35, height: 35)
button.tintColor = UIColor(red: 208/255, green: 33/255, blue: 33/255, alpha: 1.0)
button.addTarget(self, action: #selector(self.drawerClicked(_:)), for: UIControlEvents.touchUpInside)
let barButton = UIBarButtonItem(customView: button)
self.navigationItem.leftBarButtonItem = barButton
}
当我点击按钮时，它会调用一个显示警报的方法。这是方法:
func drawerClicked(_ sender: Any) {
let cancelAction = UIAlertAction(title: "Cancel", style: .default, handler: nil)
let wifiAction = UIAlertAction(title: "Wi-Fi", style: .default) { (UIAlertAction) in
let url = URL(string: "App-Prefs:root=WIFI")
UIApplication.shared.openURL(url!)
}
let alert = UIAlertController(title: "Wi-Fi)", message: "Please, connect your WI-FI", preferredStyle: .alert)
alert.addAction(cancelAction)
alert.addAction(wifiAction)
self.present(alert, animated: true, completion: nil)
}
效果很好，但是当对话框出现时，我的 UIImage 改变了颜色。红色变成灰色。关闭对话框后，UIImage 恢复为红色。我希望该图像即使在出现警报时也保持红色，只是比屏幕的其余部分稍暗。我该怎么做？