系统自带cell.imageView.image的大小

    cell.imageView.image = [UIImage imageNamed:[imageArray objectAtIndex:[indexPath row]]];

    

  

    CGSize itemSize = CGSizeMake(60, 50);

    UIGraphicsBeginImageContext(itemSize);

    CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);

    [cell.imageView.image drawInRect:imageRect];

    cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();