Winform 控制同一窗体只能打开一次的方法！

方法一：

        /// <summary>
        /// 控制只弹出一个子窗体
        /// </summary>
        /// <param name="type">子窗体类型</param>
        public void FilmShow(Type type)
        {
            Form[] f = this.MdiChildren;
            foreach (Form form in f)
            {
                if (form.GetType().Name == type.Name)
                {
                    form.Dock = DockStyle.Fill;
                    form.Activate();
                    return;
                }
            }
            Assembly a = Assembly.GetExecutingAssembly();
            Form ff = (Form)a.CreateInstance(type.FullName);
            ff.MdiParent = this;
            ff.Dock = DockStyle.Fill;
            ff.Show();
        }

 

方法二：

        public bool checkchildFrmExist(string childFrmName)
        {
            foreach (Form childFrm in this.MdiChildren)
            {
                if (childFrm.Text.ToString() == childFrmName)
                {
                    if (childFrm.WindowState == FormWindowState.Minimized)
                    {
                        childFrm.WindowState = FormWindowState.Normal;
                    }
                    childFrm.Activate();
                    return true;
                }
            }
            return false;
        }

 

模式窗体的控制：

 

        /// <summary>
        /// 该窗体以模式窗体形式弹出
        /// </summary>
        /// <param name="type"></param>
        public void FilmShowDialog(Type type)
        {
            Form[] f = this.MdiChildren;
            foreach (Form form in f)
            {
                if (form.GetType().Name == type.Name)
                {
                    form.Activate();
                    return;
                }
            }
            Assembly a = Assembly.GetExecutingAssembly();
            Form ff = (Form)a.CreateInstance(type.FullName);
            ff.ShowDialog();
        }