Question

I made a function to truncate a string in the code behind file. But how do i use it in the aspx file?

This is the textbox:

<asp:TemplateField HeaderText="page" HeaderStyle-Wrap="true">
    <ItemTemplate>
        <a href='<%# makepageURL( Eval("page") )%> '>
            <%# Eval("page")%>
        </a>
    </ItemTemplate>
    <EditItemTemplate>
        <asp:TextBox ID="txtpage" TextMode="SingleLine" Rows="1" Width="100%" runat="server" Text='<% #Bind("page") %>' />
    </EditItemTemplate>
</asp:TemplateField>

And this is my function:

Public Function TrimString(ByVal Value As String, ByVal Length As Integer) As String
    If Value.Length > 20 Then
        Return Value.Substring(Value.Length - (20 - 3)) + "..."
    End If

    Return Value   
End Function

Answer 1

It’s not an issue of how to use it, but actually when to use it?

If you had a regular span, you could do this:

<span><%: TrimString("somestring") %></span>

But this is a TextBox your dealing with (user input).

When should it truncate?

On Form Submit? (that would make sense).

As they type (well then you’d need to use JavaScript).

By the looks of your code snipper, your using a FormView.

So i wouldn’t be calling it from the ASPX (which the equivalent of executing code during Page Render), i would be calling it during the Edit/Submit event, server-side event handler.

In other words, truncate the value the user put in, after they have submitted the form and before you persist to the database.