ios 从视图控制器调用应用程序委托方法
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Call app delegate method from view controller
提问by Memon Irshad
I want to know if I can call an app delegate method from another ViewController.
我想知道是否可以从另一个 ViewController 调用应用程序委托方法。
When the app starts, the application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Booli method is called. Can I call this method a second time from another view controller?
当应用程序启动时，将application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool调用 i 方法。我可以从另一个视图控制器第二次调用这个方法吗？
回答by Juan Carlos Ospina Gonzalez
Not sure why you want to do this. You probably shouldn't, but for the purpose of answering the question here it is:
不知道你为什么要这样做。你可能不应该，但为了回答这里的问题，它是：
// get a reference to the app delegate
let appDelegate: AppDelegate? = UIApplication.shared.delegate as? AppDelegate
// call didFinishLaunchWithOptions ... why?
appDelegate?.application(UIApplication.shared, didFinishLaunchingWithOptions: nil)
回答by Tejinder
In Swift 3.0, you can call as:
在 Swift 3.0 中，您可以这样调用：
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.anyAppDelegateInstaceMethod()
回答by sschunara
This method is called just once when app launches. You can't from ViewController. Instead make user defined method in AppDelegete. and call that method from ViewController. By getting object of AppDelegate.
该方法在应用启动时只调用一次。你不能从 ViewController。而是在 AppDelegete 中创建用户定义的方法。并从 ViewController 调用该方法。通过获取 AppDelegate 的对象。
AppDelegate *appDel = (AppDelegate *)[UIApplication sharedApplication].delegate;
[appDel <Your method>];
回答by Anurag Sharma
Constructors:
构造函数：
Add a constructor in AppDelegate Class at the end of code
在 AppDelegate 类中代码末尾添加构造函数
Swift 3.x
斯威夫特 3.x
class func shared() -> AppDelegate
{
return UIApplication.shared.delegate as! AppDelegate
}
Swift 2.x
斯威夫特 2.x
func appDelegate () -> AppDelegate
{
return UIApplication.sharedApplication().delegate as! AppDelegate
}
and add a var like this
并添加一个像这样的 var
var boolForFun = Bool()
How to use reference in your class?
如何在课堂上使用引用？
Method
方法
for swift 3x access functins or variables
用于快速 3x 访问函数或变量
AppDelegate.shared().boolForFun = true
for else
为别的
appDelegate().methodFoo()
Variable
多变的
appDelegate().foo
