如何将数据从Objective C传递给Swift？

Question

如何将数据对象从Objective C文件传递到Swift文件？

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{

    if([[segue identifier] isEqualToString: @"details"]){
    //create the swift file and set the property I want to pass here


    }

}

在迅速视图中:

import Foundation
import UIKit
import CoreLocation


public class SwiftViewController: UIViewController{

    var passedObject:NPSCustomObject!

    public override func viewDidLoad() {

    }

Answer 1

我更喜欢使用NotificationCenter:

目标C到斯威夫特

目标C.

NSDictionary *myData = @{@"data1" : @"value1", @"data2": @"value2"};
[[NSNotificationCenter defaultCenter] postNotificationName:@"myNotificationName" object:nil userInfo:myData];

迅速

NotificationCenter.default.addObserver(forName:NSNotification.Name(rawValue: "myNotificationName"), object:nil, queue:nil, using:yourFunction)

func yourFunction(notification:Notification) -> Void {
 if let extractInfo = notification.userInfo {
             print(" my data: \(extractInfo["data1"])");
        }
    }

Answer 2

如果在情节提要中将“详细信息” segue设置为传递给类型的视图控制器SwiftViewController（应该用于您暗示的工作流），则您无需创建后者的实例-该segue已经为您完成。你可以在里面访问它prepareForSegue的segue.destinationViewController。

假设您的项目已经设置了正确的头文件，以将Swift桥接到（Obj）C，则只需将其segue.destinationViewController转换为正在使用的类型，即可访问其成员。例如：

if([[segue identifier] isEqualToString: @"details"]){
    SwiftViewController *vc = (SwiftViewController *)segue.destinationViewController;
    vc.passedObject = // put your instance of NPSCustomObject here
}

Answer 3

我发现NSUserDefaults有一些'hack'保存数据:

Objective-C类:

NSString *myObjcData = @"from Objective-C";

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setValue:myObjcData forKey:@"data"];
[defaults synchronize];

Swift类:

let prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()

override func viewDidLoad() {

    super.viewDidLoad()

    // Receive data ---> with NSUserdefaults
    let mySwiftData: AnyObject? = prefs.valueForKey("data")
    println("data is \(mySwiftData)")

}

它不是很优雅,但我保证它有效!希望能帮助到你.