来自AppDelegate的Xcode更新视图控制器UIImage

Question

我想从ViewController.m AppDelegate调用一个函数。 我将很好地访问该功能，但是View Controller功能无法正常工作。

在AppDelegate.m文件中，我有：

#import "AppDelegate.h"
#import "UserList.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    return YES;
}

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo
{
    NSString *UserName = [NSString stringWithFormat:@"%@",[[userInfo objectForKey:@"aps"] objectForKey:@"from"]];
    if (application.applicationState == UIApplicationStateActive) 
    {
        UserList *ul = [[UserList alloc] init];
        [ul AddUserWhenNotExists:UserName];
    }
}

视图控制器的UserList.m文件：

#import "UserList.h"

- (void)viewDidLoad
{
    [super viewDidLoad];
}
- (void)accessFromAppDelegate
{
    UIImageView *setting =[[UIImageView alloc] initWithFrame:CGRectMake(0,20,61,60)];
    setting.image=[UIImage imageNamed:@"setting_icon.png"];
    [setting setUserInteractionEnabled:YES];

    UITapGestureRecognizer *singleTap =  [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(SettingClick:)];
    [singleTap setNumberOfTapsRequired:1];
    [setting addGestureRecognizer:singleTap];
    [self.view addSubview:setting];

}

在视图控制器的UserList ，不附加setting_icon.png 。 我的代码错了吗？ 请帮忙。

谢谢你的时间。

Answer 1

您可能要使用NSNotificationCenter： https : //developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/nsnotificationcenter_Class/Reference/Reference.html

您可以使用它来告诉UIViewController什么时候发生。 这是一些示例代码： https : //stackoverflow.com/a/9127852/2661880