iOS中怎么获取UILabel的高度

ios7 以后 sizeWithFont 方法被废弃了。现在取uilabel的高度使用NSString的类方法boundingRectWithSize

NSAttributedString *attrStr = ... // your attributed string

CGFloat width = 300; // whatever your desired width is

CGRect rect = [attrStr boundingRectWithSize:CGSizeMake(width, 10000) options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading context:nil];