Question

I’m using ASP.NET web forms in Visual Studio 2010. How can I create UI controls and such programmatically? For example, I want to define in separate form files to have a side-bar menu and such, and then the resulting pages will inherit that functionality. In my base class, I added a new control to this.Controls, but generating the page throws an exception, saying that the control must be placed inside a tag with runat="server". If I want to generate these controls programmatically, how do I place them inside such a tag?

Answer 1

You write:

and then the resulting pages will inherit that functionality

which makes me believe you are better off using Master Pages, here’s a tutorial on ASP.NET master pages (use Google to find more). However, inheritance itself can also easily be achieved by taking any existing control and extending it:

class MyTextBox : TextBox
{
    // your extensions and overrides
}

---

Later you write:

I added a new control to this.Controls, but generating the page throws an exception, saying that the control must be placed inside a tag with runat=”server”.

which is not entirely related. This is simply true: every server control must have a runat="server"_ or it won’t be recognized by the ASP.NET parser. I.e., like this:

<!-- existing server control, placed on a page -->
<asp:Label runat="server" Id="MyOwnLabel" />
<!-- your own server control, placed on a page -->
<my:MyTextBox runat="server" ID="ReallyMyTextBox" />