ios6和io7通过字符串的字数获取应该要的size

转载请注明http://blog.csdn.net/h289962920/article/details/29857665

可以一个全局的工具类这样全局都可以调用

+(CGSize)textSize:(NSString*)str withWidth:(CGFloat)width withFont:(NSInteger)font{
CGSize size;
if (iosVersion>=7.0) {
NSDictionary *attribute = @{NSFontAttributeName: [UIFont systemFontOfSize:font]};
size = [str boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX) options: NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:attribute context:nil].size;
}else{
size=[str sizeWithFont:[UIFont systemFontOfSize:font] constrainedToSize:CGSizeMake(width, CGFLOAT_MAX) lineBreakMode:NSLineBreakByCharWrapping|NSLineBreakByWordWrapping];
}
return size;
}