ios 将数据从应用程序委托传递到视图控制器
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Passing Data from App delegate to View Controller
提问by Alex
I need to Pass an string from App delegate to my Initial View Controller , Can somebody listed me the best way to do it , also i tried to Save and Retrieve using NS user Defaults, but i doesn't work out properly .
我需要将一个字符串从 App 委托传递到我的初始视图控制器，有人能列出我最好的方法吗，我也尝试使用 NS 用户默认值保存和检索，但我没有正常工作。
采纳答案by Skanda
Interface:
界面：
@interface MyAppDelegate : NSObject {
NSString *myString;
}
@property (nonatomic, retain) NSString *myString;
...
@end
and in the .m file for the App Delegate you would write:
在 App Delegate 的 .m 文件中，你会写：
@implementation MyAppDelegate
@synthesize myString;
myString = some string;
@end
Then, in viewcontroller.m file you can fetch:
然后，在 viewcontroller.m 文件中，您可以获取：
MyAppDelegate *appDelegate = (MyAppDelegate*)[[UIApplication sharedApplication] delegate];
someString = appDelegate.myString; //..to read
appDelegate.myString = some NSString; //..to write
回答by RyanPliske
Here it is for Swift:
这是 Swift 的：
View Controller
视图控制器
let appDelegate = UIApplication.sharedApplication().delegate as AppDelegate
Furthermore, if you have an object that you want to pass between view controllers (for example, I had CloudKit data I wanted to share) add this to the App Delegate:
此外，如果您有一个要在视图控制器之间传递的对象（例如，我想要共享 CloudKit 数据），请将其添加到App Delegate：
/* Function for any view controller to grab the instantiated CloudDataObject */
func getCloudData() ->CloudData{
return cloudDataObject
}
Then back in the View Controller
然后回到视图控制器
var model : CloudData = self.appDelegate.getCloudData()
回答by Odrakir
You can access your root view controller like this from the app delegate:
您可以像这样从应用程序委托访问您的根视图控制器：
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
MyViewController* mainController = (MyViewController*) self.window.rootViewController;
[mainController passData:@"hello"];
return YES;
}
回答by Mu Sa
Using Swift 4.2:
使用 Swift 4.2：
Passing Data from AppDelegate to ViewController:
将数据从 AppDelegate 传递到 ViewController：
let yourViewController = self.window?.rootViewController as? YourViewController
yourViewController?.passData(YOUR_DATA) // pass data
let data = yourViewController?.getData() // access data
Passing Data from ViewController to AppDelegate:
将数据从 ViewController 传递到 AppDelegate：
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.passData(YOUR_DATA) // pass data
let data = appDelegate.getData() // access data
Add below code to YourViewController or AppDelegate:
将以下代码添加到 YourViewController 或 AppDelegate：
private var data : String? // String? or any type you want
func getData() -> String? {
return data
}
func passData(_ data : String?) {
self.data = data
}
