NSString * content = @"測試高度";

CGSize _textLabelSize ?= [content boundingRectWithSize:CGSizeMake(ScreenWidth-20, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName:[UIFont boldSystemFontOfSize:14]} context:nil].size;

枚舉要設(shè)置兩個 NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading 可以解決有時高度不準(zhǔn)的問題。