iOS7中Cell高度 Label高度自适应


- (float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{

    NSString *str = [_dataArray objectAtIndex:indexPath.row];
    UIFont *tfont = [UIFont systemFontOfSize:14.0];
    NSDictionary * dic = [NSDictionary dictionaryWithObjectsAndKeys:tfont,NSFontAttributeName,nil];
    //   ios 7
    CGSize sizeText = [str boundingRectWithSize:CGSizeMake(320, 1000) options:NSStringDrawingUsesLineFragmentOrigin attributes:dic context:nil].size;
    //   ios 6
    CGSize sizeText1 = [str sizeWithFont:[UIFont systemFontOfSize:16.0f] constrainedToSize:CGSizeMake(320, 1000) lineBreakMode:NSLineBreakByCharWrapping];
    return sizeText1.height+50; 	

}