winform 子父窗体的设置，获取其子窗体

1. 子父窗体的设置  以及判断是否其子窗体，存在子窗体是否Activate显示获取焦点。 呵呵 交流一下  有心得的朋友请探讨给点建议。

2.    public class FormHelper
       {
           /// <summary>
           /// 设置子窗体
           /// </summary>
           /// <param name="type">类型</param>
           /// <param name="parent">父窗体</param>
           /// <returns></returns>
           public static Form ShowForm(Type type, Form parent)
           {
               Form retForm;
               if (!ChildExists(type, parent, true, out retForm))
               {
                   ConstructorInfo[] cons = type.GetConstructors();
                   if (cons.Length > 0)
                   {
                       Object obj =cons[0].Invoke(null);
                       if (obj is Form)
                       {
                           retForm = obj as Form;
                           retForm.MdiParent = parent;
                           retForm.Show();
                           retForm.Activate();
                       }
                   }
               }
               return retForm;
           }
           /// <summary>
           /// 子窗体是否存在
           /// </summary>
           /// <param name="type">类型</param>
           /// <param name="parent">父窗体</param>
           /// <param name="showForm">是否显示</param>
           /// <param name="form">子窗体</param>
           /// <returns></returns>
           public static bool ChildExists(Type type, Form parent, bool showForm, out Form form)
           {
               for (int i = 0; i < parent.MdiChildren.Length; i++)
               {
                   Form child = parent.MdiChildren[i];
                   if (child.GetType() == type)
                   {
                       if (showForm)
                       {
                           child.Visible = true;
                           child.Activate();
                       }
                       form = child;
                       return true;
                   }
               }
               form = null;
               return false;
           }
          
       }

3.  Form f = Application.OpenForms["窗体名称"]; //查找窗体是否打开   存在则返回 窗体对象 否则null