有一個小小的提醒就是當您在練習時記得不要將AlertController寫在viewdidLoad因為可能會沒顯示出來，建議使用一個button或是在比viewdidLoad晚執行的時候處理
一般的AlertController建立
let alertController = UIAlertController(title: "建立Alert", message: "建立成功了唷！", preferredStyle: .alert);
//建立AlertAction，如果再按下Action後要做動作就將print的位子寫入你要的動作，像取消通常沒做動作可將handler帶入nil即可
let alertActionOK = UIAlertAction(title: "確定", style: .default, handler: {
action in
print("寫入你要的動作");
});
let alertActionCancel = UIAlertAction(title: "取消", style: .destructive, handler: nil);//style通常都是使用default，如使用.destructive該action會直些顯示紅色
alertController.addAction(alertActionOK);//在AlertController加入確定鈕
alertController.addAction(alertActionCancel);//在AlertController加入取消鈕
//顯示出AlertController的方法有下面兩種。
self.present(alertController, animated: true, completion: nil);
// self.show(alertController, sender: nil);
改變AlertController的背景色
let alertController = UIAlertController(title: "背景色？", message: "改變背景色", preferredStyle: .alert);
//加入背景色
let firstView = alertController.view.subviews.first;
let backView = firstView?.subviews.first;
for subview in (backView?.subviews)!{
subview.backgroundColor = UIColor.yellow;
subview.layer.cornerRadius = 10.0;
subview.alpha = 1;
}
let alertActionOK = UIAlertAction(title: "確定", style: .default, handler: nil);
alertController.addAction(alertActionOK);
self.present(alertController, animated: true, completion: nil);
改變AlertAction的文字顏色
let alertController = UIAlertController(title: "Action顏色", message: "改變Action顏色", preferredStyle: .alert);
//這行是兩個Action顏色都改一樣
// alertController.view.tintColor = UIColor.brown
let alertActionOK = UIAlertAction(title: "確定", style: .default, handler: nil);
//改變ActionOK的顏色為橘色
alertActionOK.setValue(UIColor.orange, forKey: "titleTextColor");
let alertActionCancel = UIAlertAction(title: "取消", style: .default, handler: nil);
// 改變ActionCancel的顏色為綠色
alertActionCancel.setValue(UIColor.green, forKey: "titleTextColor");
alertController.addAction(alertActionOK);
alertController.addAction(alertActionCancel);
self.present(alertController, animated: true, completion: nil);
改變AlertController的Title文字顏色
let alertController = UIAlertController(title: "Title顏色改變", message: "預設顏色為黑色唷！改為紅色了", preferredStyle: .alert);
let myTitleString = NSMutableAttributedString(string: "Title顏色改變",
attributes: [NSFontAttributeName:UIFont(name: "Georgia", size: 18.0)!]);
myTitleString.addAttribute(NSForegroundColorAttributeName,
value: UIColor.red,
range: NSRange(location: 0,
length: "Title顏色改變".characters.count));
alertController.setValue(myTitleString, forKey: "attributedTitle");
let alertActionOK = UIAlertAction(title: "確定", style: .default, handler: nil);
alertController.addAction(alertActionOK);
self.present(alertController, animated: true, completion: nil);
改變AlertController的Message文字顏色
let message = "改變訊息的顏色變為橘色了喔！"
let alertController = UIAlertController(title: "Message顏色改變", message: message, preferredStyle: .alert);
let messageMutableString = NSMutableAttributedString(string: message, attributes: [NSFontAttributeName:UIFont(name: "Georgia", size: 15.0)!]);
messageMutableString.addAttribute(NSForegroundColorAttributeName,
value: UIColor.orange,
range: NSRange(location: 0, length: message.characters.count));
alertController.setValue(messageMutableString, forKey: "attributedMessage");
let alertActionOK = UIAlertAction(title: "確定", style: .default, handler: nil);
alertController.addAction(alertActionOK);
self.present(alertController, animated: true, completion: nil);
AlertController中加入TextField
let alertController = UIAlertController(title: "加入textField?", message: "下方有TextField了", preferredStyle: .alert);
alertController.addTextField(configurationHandler: {(textField : UITextField!) -> Void in
textField.placeholder = "請輸入文字"
//怎麼運用看個人了喔！如果想要鎖定字數之類的請慘考此篇http://h81061678.blogspot.tw/2016/12/swift3-alertaction.html
});
let alertActionOK = UIAlertAction(title: "確定", style: .default, handler: nil);
alertController.addAction(alertActionOK);
self.present(alertController, animated: true, completion: nil);
以上的用法希望能夠對大家有幫助唷！
