根据字数自适应高度的UILabel

- (UILabel *) getLabelHeightFixedWithText: (NSString *) text {

	UIFont *font = [UIFont boldSystemFontOfSize: 12.0f];
	int width = 225, height = 10000;
    NSMutableDictionary *attrs = [[NSMutableDictionary alloc] init];
	[attrs setObject: font forKey: NSFontAttributeName];
    CGRect size = [text boundingRectWithSize:CGSizeMake(width, height) options: NSStringDrawingUsesLineFragmentOrigin attributes: attrs context: nil];
	UILabel *label = [[UILabel alloc] initWithFrame: CGRectMake(0, 0, size.size.width, size.size.height)];
	label.numberOfLines = 0;//一定要设置行数为0
	label.font = font;
	label.lineBreakMode = NSLineBreakByWordWrapping;
	label.text = (text ? text : @"");
	label.backgroundColor = [UIColor clearColor];
	label.textColor = [UIColor blackColor];

	return label;

}