动态计算uilabel的高度,
CGSize size = [[TTGlobalDatasharedInstance].config.urgentMethodsizeWithFont:self.urgentLabel.fontconstrainedToSize:CGSizeMake(self.urgentLabel.frame.size.width, MAXFLOAT) lineBreakMode:NSLineBreakByWordWrapping];
[self.urgentLabelsetFrame:CGRectMake(self.urgentLabel.frame.origin.x, self.urgentLabel.frame.origin.y, self.urgentLabel.frame.size.width, size.height)];
self.urgentLabel.text = [TTGlobalDatasharedInstance].config.urgentMethod;