You are developing a Asp.net web application tht includes a panel control that has ID contentsection.You need to add a textBox control to the panel control.()
A、A.this.RequireControlState(this.LoadControl(typeof(TextBox),null));
B、B.this.ContentSection.control.add(this.FindControl(ContentSection.ID + "asp:TextBox"));
C、C.this.ContentSection.control.add(this.LoadControl(typeof(TextBox),null));
D、D.this.LoadComplete("asp:TextBox").IntiantiateIn(Content Section)