将行动绑定到UIButton

Question

在我的AppController中,我正在使用以下代码加载View.

- (void) loadSettingsController {
    settingsViewController = [[SettingsViewController alloc] initWithNibName:@"SettingsView" bundle:nil];
    UIButton *button = settingsViewController.loginButton;
    [button addTarget:self action:@selector(saveSettings:) forControlEvents:UIControlEventTouchUpInside];
}

- (IBOutlet) saveSettings:(id) sender

稍后将视图添加到带有代码的窗口中

[window addSubview:[settingsViewController view]];

一切正常,但在使用调试器时按下按钮时,不会调用saveSettings操作."loginButton"属性连接到Interface Builder中的按钮.

你能看到这段代码有什么问题吗？

Answer 1

将IBOutlet更改为IBAction

- (IBAction) saveSettings:(id) sender

这是因为你在调用viewDidLoad之前尝试访问你的对象.你必须在viewDidLoad被调用之前等待,有很多方法可以实现.

将其添加到您的SettingViewController viewDidLoad函数中

 [[NSNotificationCenter defaultCenter] postNotificationName:@"SettingsViewDidLoad" object:nil];

这对你想要访问按钮的ViewController

- (void) loadSettingsController {
       settingsViewController = [[SettingsViewController alloc] initWithNibName:@"SettingsView" bundle:nil];
       [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(initControls) name:@"SettingsViewDidLoad" object:nil];
}

-(void)initControls{
       UIButton *button = settingsViewController.loginButton;
       [button addTarget:self action:@selector(saveSettings:) forControlEvents:UIControlEventTouchUpInside];
}