ReactiveCocoa学习（一）

UITextField *tfd=[[UITextField alloc]initWithFrame:CGRectMake(50, 50, 200, 30)];
tfd.borderStyle=UITextBorderStyleRoundedRect;
tfd.placeholder=@"请输入您的姓名";
tfd.font=[UIFont systemFontOfSize:14];
[self.view addSubview:tfd];
//监听文本框值的改变
[tfd.rac_textSignal subscribeNext:^(id x) {
//打印文本框输入的值
NSLog(@"%@",x);
}];

//****************& 例一 &****************//

[[tfd.rac_textSignal filter:^BOOL(id value) {
NSString *textvalue=value;
return textvalue.length>3;
}]

subscribeNext:^(id x) {
NSLog(@"%@",x);
}
];
//或者写成这样
//****************& 例二 &****************//
RACSignal *tfdSingale=tfd.rac_textSignal;
RACSignal *tfdSingfilter=[tfdSingale filter:^BOOL(id value) {
NSString *textvalue=value;
return textvalue.length>3;
}];
[tfdSingfilter subscribeNext:^(id x) {
NSLog(@"%@",x);
}];

[[[tfd.rac_textSignal
map:^id(id value) {
NSString *textvalue=value;
return @(textvalue.length);
}]
filter:^BOOL(id value) {
NSInteger numvalue=[value integerValue];
return (numvalue>3);
}]
subscribeNext:^(id x) {
NSLog(@"%@",x);
}];

//判断是否是有效的值
RACSignal *validUsernameSignal =
[tfd.rac_textSignal
map:^id(NSString *text) {
return @([self isValidUsername:text]);
}];

//打印结果
[validUsernameSignal subscribeNext:^(id x) {
NSLog(@"%@",x);
}];

[[tfd.rac_textSignal
map:^id(NSNumber *text) {
return [text boolValue]?[UIColor clearColor]:[UIColor yellowColor];
}]
subscribeNext:^(UIColor * color) {
tfd.backgroundColor=color;
}];

利用ReactiveCocoa提供的宏设置

RAC(tfd,backgroundColor)=[tfd.rac_textSignal map:^id(id value) {
return [value boolValue]?[UIColor clearColor]:[UIColor yellowColor]
;
}];

UITextField *tfd=[[UITextField alloc]initWithFrame:CGRectMake(50, 50, 200, 30)];
tfd.borderStyle=UITextBorderStyleRoundedRect;
tfd.placeholder=@"请输入您的姓名";
tfd.font=[UIFont systemFontOfSize:14];
[self.view addSubview:tfd];

UITextField *tfd2=[[UITextField alloc]initWithFrame:CGRectMake(50, 100, 200, 30)];
tfd2.borderStyle=UITextBorderStyleRoundedRect;
tfd2.placeholder=@"请输入您的密码";
tfd2.font=[UIFont systemFontOfSize:14];
[self.view addSubview:tfd2];

UIButton *btn=[[UIButton alloc]initWithFrame:CGRectMake(50, 150, 200, 30)];
[btn setTitle:@"点我啊" forState:UIControlStateNormal];
[btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];

RACSignal *useSingle=[tfd.rac_textSignal map:^id(NSString * value) {

return @([self isValidUsername:value]);
}];

RACSignal *pwdSingle=[tfd2.rac_textSignal map:^id(NSString * value) {

return @([self isValidPassword:value]);
}];

RAC(tfd,backgroundColor)=[useSingle map:^id(id value) {
return [value boolValue]?[UIColor clearColor]:[UIColor yellowColor]
;
}];

RAC(tfd2,backgroundColor)=[pwdSingle map:^id(id value) {
return [value boolValue]?[UIColor clearColor]:[UIColor yellowColor]
;
}];

//把信号两个信号连接起来，判断按钮的状态
RACSignal *btnsingle=[RACSignal combineLatest:@[useSingle,pwdSingle] reduce:^id(NSNumber *uservalid,NSNumber *pwdvalid){
return @([uservalid boolValue]&&[pwdvalid boolValue]);
}];

[btnsingle subscribeNext:^(id x) {
btn.enabled=[x boolValue];
btn.backgroundColor=[x boolValue]?[UIColor redColor]:[UIColor grayColor];
}];