How to assign a method's output to a textbox value without code behind

Question

How do I assign a method\'s output to a textbox value without code behind?

<%@ Page Language=\"VB\" %>


        

Answer 1

Have you tried using an HTML control instead of the server control? Does it also cause a compilation error?

<input type="text" id="TextBox4" runat="server" value="<%=TextFromString%>" />

Answer 2

There's a couple of different expression types in .ASPX files. There's:

<%= TextFromMethod %>

which simply reserves a literal control, and outputs the text at render time.

and then there's:

<%# TextFromMethod %>

which is a databinding expression, evaluated when the control is DataBound(). There's also expression builders, like:

<%$ ConnectionStrings:Database %>

but that's not really important here....

So, the <%= %> method won't work because it would try to insert a Literal into the .Text property...obviously, not what you want.

The <%# %> method doesn't work because the TextBox isn't DataBound, nor are any of it's parents. If your TextBox was in a Repeater or GridView, then this method would work.

So - what to do? Just call TextBox.DataBind() at some point. Or, if you have more than 1 control, just call Page.DataBind() in your Page_Load.

Private Function Page_Load(sender as Object, e as EventArgs)
   If Not IsPostback Then
      Me.DataBind()
   End If
End Function