How can I get this VB code to work in C # using the same variable?

Question

I am trying to figure out how to convert the following code sample to C # using the same implicit definition as VB. I know that I can define a button and a common control as two objects and make it work, but I would like to use the same "ctlHTML" variable in C # as VB. Can anyone help with this?

Sub MySub(varInput As String, pnl As Panel) Dim ctlHTML = Nothing Select Case varInput Case "btn" ctlHTML = New HtmlButton Case "lbl" ctlHTML = New HtmlGenericControl() End Select With ctlHTML .Style.Add("font-size", "14px") End With pnl.Controls.Add(ctlHTML) End Sub 

Answer 1

You cannot directly convert the code. You will have to specify the type of variable. The highest class in the inheritance chain that supports all your members will be HtmlControl :

 HtmlControl control = null; switch(varInput) { case "btn": control = new HtmlButton(); break; case "lbl": control = new HtmlGenericControl(); break; } if(control != null) { control.Style.Add("font-size", "14px"); pnl.Controls.Add(control); } 

Answer 2

To change the Style property, the minimum value of the control must be HtmlControl . Therefore, you need to declare the ctlHtml variable as this type.

You should also check if ctlHtml properly initialized.

I believe your code should look something like this:

 public void MySub(string varInput, Panel pnl) { HtmlControl ctlHtml; switch(varInput) { case "btn": ctlHtml = new HtmlButton(); break; case "lbl": ctlHtml = new HtmlGenericControl(); break; default: ctlHtml = null; break; } if (ctlHtml != null) { ctlHtml.Style.Add("font-size", "14px"); pnl.Controls.Add(ctlHtml); } } 

Answer 3

Since HtmlGenericControl and HtmlButton both inherit from HtmlControl , you can declare ctlHTML as this type ( HtmlControl ) and it will work.

See here: http://msdn.microsoft.com/en-us/library/system.web.ui.htmlcontrols.htmlcontrol.aspx