ReactiveCocoa 两个开关互异绑定怎么写？

Question

假设有两个 Siwtch 需要互异绑定，用 rac 该怎么写？

UISwitch *switch1;
UISwitch *switch2;

switch1.action = {
    switch2.on = !switch2.on;
}

switch2.action = {
    switch1.on = !switch1.on;
}

Answer 1

这样？

switch1.on = YES;
switch2.on = NO;
RACChannelTerminal *t1 = switch1.rac_newOnChannel;
RACChannelTerminal *t2 = switch2.rac_newOnChannel;
[[t1 map:^id(NSNumber *on) {
    return @(![on boolValue]);
}] subscribe:t2];
[[t2 map:^id(NSNumber *on) {
    return @(![on boolValue]);
}] subscribe:t1];

Answer 2

找到一种解决方案：

RACChannelTerminal *aButtonChannel = [aButton rac_newSelectedChannel];
RACChannelTerminal *bButtonChannel = [bButton rac_newSelectedChannel];
[[aButtonChannel not] subscribe:bButtonChannel];
[[bButtonChannel not] subscribe:aButtonChannel];