c# - 在 .Net 3.5 中使用动态关键字

Question

我在 visual studio 2013 中使用 .net v4.5 编写了这段代码。我遇到的问题是我现在不得不下降到 .net v3.5 并且 dynamic 关键字由于缺少程序集引用而抛出错误。 .net v3.5 中是否有与“动态”等效的类型，或者我可以通过某种方式获得与以下相同的结果？

我想我可能已经找到答案 here 了，但是当我添加 .Attributes 或 .Text 属性修改时 var 抛出错误。

private void CreateControl<T>(string objText,
                              Panel pnl,
                              string HTMLTag = "<td>",
                              string applicantID = "",
                              EventHandler hndl = null)
{
    pnl.Controls.Add(new LiteralControl(HTMLTag));
    dynamic obj = Activator.CreateInstance(typeof(T));
    obj.Text = objText;

    if (applicantID != string.Empty)
    {
        obj.Attributes.Add("ApplicantID", applicantID);
    }
    if (hndl != null)
    {
        obj.Click += new EventHandler(hndl);
    }

    pnl.Controls.Add(obj);
    pnl.Controls.Add(new LiteralControl(HTMLTag.Insert(1, "/")));
}

Answer 1

我没有尝试以某种必然会失败的方式将其组合在一起，而且由于 .net v3.5 中没有“动态”控件，我决定完全放弃此方法并编写一些重载。这种方式在这一点上似乎更安全；工作原理相同，只是多了一点代码...

    #region CreateControl() Overloads
            /// <summary>
            /// Creates a LinkButton control.
            /// </summary>
            /// <param name="objText">.Text property of this LinkButton control.</param>
            /// <param name="pnl">Panel this control will be attached to.</param>
            /// <param name="hndl">Event handler attached to this LinkButton control.</param>
            /// <param name="HTMLTag">Opening tag used to contain this control.</param>
            private void CreateControl(string objText,
                                       Panel pnl,
                                       EventHandler hndl,
                                       string HTMLTag)
            {
                pnl.Controls.Add(new LiteralControl(HTMLTag));
                LinkButton obj = new LinkButton();
                obj.Text = objText;
                obj.Click += new EventHandler(hndl);

                pnl.Controls.Add(obj);
                pnl.Controls.Add(new LiteralControl(HTMLTag.Insert(1, "/")));
            }
            /// <summary>
            /// Creates a Label control.
            /// </summary>
            /// <param name="objText">.Text property of this Label control.</param>
            /// <param name="pnl">Panel this control will be attached to.</param>
            /// <param name="HTMLTag">Opening tag used to contain this control.</param>
            private void CreateControl(string objText,
                                       Panel pnl,
                                       string HTMLTag)
            {
                pnl.Controls.Add(new LiteralControl(HTMLTag));
                Label obj = new Label();
                obj.Text = objText;

                pnl.Controls.Add(obj);
                pnl.Controls.Add(new LiteralControl(HTMLTag.Insert(1, "/")));
            }
            /// <summary>
            /// Creates the specified literal control.
            /// </summary>
            /// <param name="ControlText">HTML text containing instructions for creating the desired literal control.</param>
            /// <param name="pnl">Panel this literal control will be attached to.</param>
            private void CreateControl(string ControlText, 
                                       Panel pnl)
            {
                pnl.Controls.Add(new LiteralControl(ControlText));
            }
        #endregion