title: UITableViewCell change selectedBackgroundView alpha?
body: <p>I need to change <strong><code>alpha</code></strong> for the <code>selectedBackgroundView</code> of the <code>UITableViewCell</code>. So I do the following:</p>
  
  <pre><code>UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
  
  if (cell == nil) {
  
      cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
      cell.selectionStyle = UITableViewCellSelectionStyleBlue;
  
      UIView *bgView = [UIView new];
      bgView.backgroundColor = [UIColor redColor];
      bgView.alpha = 0.5;//This setting has no effect
      cell.selectedBackgroundView = bgView;
  }
  </code></pre>
  
  <p>Cell selected in red color, but alpha settings has no effect for bgView.</p>