每日技巧集锦

1.MDI 单实例

 private readonly Dictionary<Type, Form> _singleInstanceForms = new Dictionary<Type, Form>();

        protected Form ActivateForm<T>() where T : Form, new()
        {
            if (!this._singleInstanceForms.ContainsKey(typeof(T)))
            {
                T newForm = new T();
                // Set up the necessary properties
                newForm.MdiParent = this;
                newForm.FormClosed += delegate(object sender, FormClosedEventArgs e)
                                          {
                                              _singleInstanceForms.Remove(sender.GetType());
                                          };

                _singleInstanceForms.Add(typeof(T), newForm);
            }
            Form formToActivate = this._singleInstanceForms[typeof(T)];
            formToActivate.Show();
            formToActivate.TopLevel = false;
            formToActivate.Activate();

            return formToActivate;
        }

 

2.无法将顶级控件添加到控件

myForm.TopLevel = false;//设置Form的值，由于Form默认为顶级控件