从应用程序的委托将数据传递到视图控制器(Passing Data from App delegate

我需要从应用程序委托的字符串传递给我的初始视图控制器，有人能列出我做的最好的方法，还我试图保存并使用NS用户默认检索，但我不能正常工作了。

Answer 1:

Interface:

@interface MyAppDelegate : NSObject  {
  NSString *myString;
}
@property (nonatomic, retain) NSString *myString;
...
@end

and in the .m file for the App Delegate you would write:

@implementation MyAppDelegate
@synthesize myString;
    myString = some string;
@end

Then, in viewcontroller.m file you can fetch:

MyAppDelegate *appDelegate = (MyAppDelegate*)[[UIApplication sharedApplication] delegate];
someString = appDelegate.myString;  //..to read
appDelegate.myString = some NSString;     //..to write

Answer 2:

这是斯威夫特：

视图控制器

let appDelegate = UIApplication.sharedApplication().delegate as AppDelegate

此外，如果您有您要查看控制器之间传递一个对象（例如，我有CloudKit数据我想分享）将其添加到应用程序委托 ：

    /* Function for any view controller to grab the instantiated CloudDataObject */
func getCloudData() ->CloudData{
    return cloudDataObject
}

然后回到视图控制器

var model : CloudData = self.appDelegate.getCloudData()

Answer 3:

您可以从应用程序的委托访问您的根视图控制器是这样的：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    MyViewController* mainController = (MyViewController*)  self.window.rootViewController;
    [mainController passData:@"hello"];

    return YES;
}

Answer 4:

使用雨燕4.2：

传递数据从AppDelegate中到ViewController中：

let yourViewController = self.window?.rootViewController as? YourViewController
yourViewController?.passData(YOUR_DATA) // pass data
let data = yourViewController?.getData() // access data

从视图控制器将数据传递到AppDelegate中：

let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.passData(YOUR_DATA) // pass data
let data = appDelegate.getData() // access data

添加以下代码YourViewController或AppDelegate中：

private var data : String? // String? or any type you want
func getData() -> String? {
    return data
}
func passData(_ data : String?) {
    self.data = data
}

文章来源: Passing Data from App delegate to View Controller