//显示多行文字
CGSize size = CGSizeMake(Width_mainScreen - 59, MAXFLOAT);
UIFont *fonts = [UIFont systemFontOfSize:15.0];
NSStringDrawingOptions options = NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading;
NSDictionary * arrtibutes = @{NSFontAttributeName:fonts};
CGRect rect = [label.text boundingRectWithSize:size options:options attributes:arrtibutes context:nil];
CGSize msgSie = rect.size;
[label setFont:[UIFont boldSystemFontOfSize:15]];
label.frame = CGRectMake(43,70, Width_mainScreen - 59,msgSie.height);
label.lineBreakMode = NSLineBreakByCharWrapping;//实现文字多行显示
label.numberOfLines = 0;
UILabel 自动适应文字
原文：http://www.cnblogs.com/zs12/p/5081472.html
