self.voicetimeLabel.text = [NSString stringWithFormat:@"%02zd:%02zd",topic.voicetime / 60,topic.voicetime % 60];
02zd表示占两位,空缺的用0补齐
self.voicetimeLabel.text = [NSString stringWithFormat:@"%02zd:%02zd",topic.voicetime / 60,topic.voicetime % 60];
02zd表示占两位,空缺的用0补齐