在视图控制器和标签栏控制器之间传递数据

Question

i've got this method in my dashBoardViewController.m

   - (void)demoSetup
    {
        self.tabBar.tintColor = [UIColor colorWithRed:(160/255.0) green:(97/255.0) blue:(5/255.0) alpha:1]; // set the tab bar tint color to something cool.

        self.delegate = self;   // Just to demo that delegate methods are being called.


    }


    #pragma UITabBarController Delegate
    - (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
    {
        NSLog(@"UITabBarDelegate: shouldSelectViewController...");
        return YES;
    }

    - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
    {
        NSLog(@"UITabBarDelegate: didSelectViewController...");
    }

    - (void)tabBarController:(UITabBarController *)tabBarController willBeginCustomizingViewControllers:(NSArray *)viewControllers
    {
        NSLog(@"UITabBarDelegate: willBeginCustomizingViewControllers...");
    }

    - (void)tabBarController:(UITabBarController *)tabBarController willEndCustomizingViewControllers:(NSArray *)viewControllers changed:(BOOL)changed
    {
        NSLog(@"UITabBarDelegate: willEndCustomizingViewControllers...");
    }

    - (void)tabBarController:(UITabBarController *)tabBarController didEndCustomizingViewControllers:(NSArray *)viewControllers changed:(BOOL)changed
    {
        NSLog(@"UITabBarDelegate: didEndCustomizingViewControllers...");
    }

i've got 4 linked on it, and a view with Facebook login i need to pass from the view that contains Facebook login 2 datas (FBID, FBUSER) to my dashBoardViewController and from it pass the same data to all of my tabs, is it possible?

this is the dashBoardViewController.h

#import <UIKit/UIKit.h>
#import <FacebookSDK/FacebookSDK.h>
#import "BFPaperTabBarController.h"

@interface dashBoardViewController : BFPaperTabBarController <UITabBarControllerDelegate,FBLoginViewDelegate> 

@property (weak, nonatomic) IBOutlet FBLoginView *loginButton;

@property (retain, nonatomic) NSString *id;

@property (retain, nonatomic) NSString *first_name;


@end

Answer 1

Create FBID, FBUSER properties in the required viewcontroller classes.Then write a method to create a shared instance of the view controller in the view controller class

+ (instancetype)sharedInstance {
static MyViewController *instance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
    instance = [[self alloc] init];
});
return instance;

}

This method will return a shared instance of MyViewController class. This is a static object.

MyViewController *myViewController = [MyViewController sharedInstance];

set your properties as myViewController.fbid = yourvalue or myViewController.first_name = yourvalue

You have to implement this shared instance method in all of your view controllers. So that you can create static objects and set a not static property as static

Answer 2

Here's my understanding of the view controller setup. ----- FaceBook Login VC | --> TabBarController --|----- VC1 | |------VC2 | ------VC3

If the diagram looks right and you are trying to pass data between FaceBookLogin and VC -1, V-2 and VC -3.

You can do this by creating a subclass of TabBar Controller. In your subclass declare two properties for FBID and FBUSER. If the use successfully logs in using "FaceBook Login" page, then set these properties in the custom tabBar controller.

You can now access these properties from any VC that is part of the tabbar controller.

Let me know if you need to see some code or need more detailed explanation.