ReactiveCocoa - 簡單實用場景

Target-Action示例代碼如下：

    UIButton *btn = [[UIButton alloc]initWithFrame:CGRectMake(20, 20, 50, 50)];
    btn.backgroundColor = [UIColor redColor];
    btn.rac_command = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {
        NSLog(@"按鈕被點擊！！");
        return [RACSignal empty];
    }];

輸出：2016-05-10 14:51:36.866 testARC[9948:3012689]按鈕被點擊！！

KVO

[RACObserve(self, username) subscribeNext:^(NSString *newName) {
  NSLog(@"%@", newName);
}];

Notification示例代碼如下

[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UITextFieldTextDidBeginEditingNotification object:self.emailTextField] subscribeNext:^(id x) {
    [self.emailImageView animate];
    self.emailImageView.image = [UIImage imageNamed:@"icon-mail-active"];
    self.emailTextField.background = [UIImage imageNamed:@"input-outline-active"];
}];

[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UITextFieldTextDidEndEditingNotification object:self.emailTextField] subscribeNext:^(id x) {
    self.emailTextField.background = [UIImage imageNamed:@"input-outline"];
    self.emailImageView.image = [UIImage imageNamed:@"icon-mail"];
}];