Swift - 告警提示框(UIAlertController)的用法
自iOS8起,苹果就建议告警框使用UIAlertController来代替UIAlertView和UIActionSheel。下面总结了一些常见的用法(本文代码都已更新至Swift3)
2,除了弹出,还可以使用从底部向上滑出的样式
(注意:如果上拉菜单中有“取消”按钮的话,那么它永远都会出现在菜单的底部,不管添加的次序是如何)
3,按钮使用“告警”样式(文字颜色变红,用来来警示用户)
4,添加任意数量文本输入框(比如可以用来实现个登陆框)
5,使用代码移除提示框
6,提示框弹出后,过段时间自动移除
下面样例弹出一个不带按钮的消息提示框,过个两秒钟提示框自动消失。
1,简单的应用(同时按钮响应Handler使用闭包函数)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
|
import UIKit
class ViewController : UIViewController {
override func viewDidLoad()
{
super .viewDidLoad()
}
override func viewDidAppear(_
animated: Bool ){
super .viewDidAppear(animated)
let alertController
= UIAlertController (title: "系统提示" ,
message: "您确定要离开hangge.com吗?" ,
preferredStyle: .alert)
let cancelAction
= UIAlertAction (title: "取消" ,
style: .cancel, handler: nil )
let okAction
= UIAlertAction (title: "好的" ,
style: . default ,
handler: {
action in
print ( "点击了确定" )
})
alertController.addAction(cancelAction)
alertController.addAction(okAction)
self .present(alertController,
animated: true ,
completion: nil )
}
override func didReceiveMemoryWarning()
{
super .didReceiveMemoryWarning()
}
}
|
2,除了弹出,还可以使用从底部向上滑出的样式
(注意:如果上拉菜单中有“取消”按钮的话,那么它永远都会出现在菜单的底部,不管添加的次序是如何)
1
2
3
4
5
6
7
8
9
|
let alertController
= UIAlertController (title: "保存或删除数据" ,
message: "删除数据将不可恢复" ,
preferredStyle:
.actionSheet)
let cancelAction
= UIAlertAction (title: "取消" ,
style: .cancel, handler: nil )
let deleteAction
= UIAlertAction (title: "删除" ,
style: .destructive, handler: nil )
let archiveAction
= UIAlertAction (title: "保存" ,
style: . default ,
handler: nil )
alertController.addAction(cancelAction)
alertController.addAction(deleteAction)
alertController.addAction(archiveAction)
self .present(alertController,
animated: true ,
completion: nil )
|
3,按钮使用“告警”样式(文字颜色变红,用来来警示用户)
1
|
let okAction
= UIAlertAction (title: "好的" ,
style: .destructive, handler: nil )
|
4,添加任意数量文本输入框(比如可以用来实现个登陆框)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
import UIKit
class ViewController : UIViewController {
override func viewDidLoad()
{
super .viewDidLoad()
}
override func viewDidAppear(_
animated: Bool ){
super .viewDidAppear(animated)
let alertController
= UIAlertController (title: "系统登录" ,
message: "请输入用户名和密码" ,
preferredStyle: .alert)
alertController.addTextField
{
(textField: UITextField !)
-> Void in
textField.placeholder
= "用户名"
}
alertController.addTextField
{
(textField: UITextField !)
-> Void in
textField.placeholder
= "密码"
textField.isSecureTextEntry
= true
}
let cancelAction
= UIAlertAction (title: "取消" ,
style: .cancel, handler: nil )
let okAction
= UIAlertAction (title: "好的" ,
style: . default ,
handler: {
action in
//也可以用下标的形式获取textField
let login = alertController.textFields![0]
let login
= alertController.textFields!.first!
let password
= alertController.textFields!.last!
print ( "用户名:\(login.text)
密码:\(password.text)" )
})
alertController.addAction(cancelAction)
alertController.addAction(okAction)
self .present(alertController,
animated: true ,
completion: nil )
}
override func didReceiveMemoryWarning()
{
super .didReceiveMemoryWarning()
}
}
|
5,使用代码移除提示框
1
|
self .presentedViewController?.dismiss(animated: false ,
completion: nil )
|
6,提示框弹出后,过段时间自动移除
下面样例弹出一个不带按钮的消息提示框,过个两秒钟提示框自动消失。
1
2
3
4
5
6
7
8
|
let alertController
= UIAlertController (title: "保存成功!" ,
message: nil ,
preferredStyle: .alert)
//显示提示框
self .present(alertController,
animated: true ,
completion: nil )
//两秒钟后自动消失
DispatchQueue .main.asyncAfter(deadline: DispatchTime .now()
+ 2) {
self .presentedViewController?.dismiss(animated: false ,
completion: nil )
}
|
原文出自:www.hangge.com 转载请保留原文链接:http://www.hangge.com/blog/cache/detail_651.html