/// <summary>
/// C# 只遍歷控件子控件，不遍歷孫控件
///當控件有子控件時，需要用遞歸的方法遍歷，才能全部列出控件上的控件
/// </summary>
/// <typeparam name="T">控件類型</typeparam>
/// <param name="control">要遍歷的控件</param>
/// <param name="controlsName">控件名</param>
/// <returns></returns>
public static T GetControl<T>(Control control, string controlsName) where T : Control
{
  if (control == null) return null;
  Control _control;
  for (int i = 0; i < control.Controls.Count; i++)
  {
    _control = control.Controls[i];
    if (_control == null) return null;
    if (_control.Name == controlsName && _control is T)
      return (T)_control;
    if (_control.HasChildren)
    {
      _control = GetControl<T>(_control, controlsName);
      if (_control != null)
        return (T)_control;
    }
  }
  return null;
}
/// <summary>
/// 遍歷窗體所有子控件
/// </summary>
/// <typeparam name="T">控件類型</typeparam>
/// <param name="form">窗體名</param>
/// <param name="controlsName">控件名</param>
/// <returns></returns>
public static T GetControl<T>(Form form, string controlsName) where T : Control
{
  T _Control = null;
  for (int i = 0; i < form.Controls.Count; i++)
  {
    _Control = GetControl<T>(form.Controls[i], controlsName);
    if (_Control != null)
      return _Control;
  }
  return null;
}