错误：预期'：'''''令牌

Question

-(void)countdown:(NSTimer *)timer{

    _value -=1;
    if ((_delegate != nil) && [_delegate respondsToSelector:@selector(countdownTicker:didUpdateValue:withAction)]) { // error: expected ':' before ')' token
        [_delegate countdownTicker:self didUpdateValue:_value withAction:ZIMCountdownTickerTickAction];
    }
    if (_value <= 0) {
        [self stop];
        if ((_delegate != nil) && [_delegate respondsToSelector:@selector(countdownTicker:didUpdateValue:withAction)]) { // error: expected ':' before ')' token
            [_delegate countdownTickerDidFinish:self];
        }
    }
}

Answer 1

完全按错误说明修复：

... respondsToSelector:@selector(countdownTicker:didUpdateValue:withAction:)]
                                                                          ^

Answer 2

您需要在选择器中withAction参数的末尾加上“：”。