ReactiveCocoa - 简单实用场景

Target-Action示例代码如下：

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

输出：2016-05-10 14:51:36.866 testARC[9948:3012689]按钮被点击！！

KVO

[RACObserve(self, username) subscribeNext:^(NSString *newName) {
NSLog(@"%@", newName);
}];
Notification示例代码如下
[[[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"];
}];