ASP.NET label expression - asp.net

Question

I use this syntax all the time in case of databinding.
<asp:Label ID="myLabel" Text='<%# display_labelText(eval("myValue")) %>' runat="server" />
So I thought it would be easy to use this outside databinding:
<asp:Label ID="myLabel" Text='<%= display_labelText("myValue") %>' runat="server" />
In this case, however, the literal text between the quotes is displayed, and not the intended function value. What is wrong here?

Answer 1

As noted, the "#" is ONLY for use inside of a databound control (listview, repeater, gridview etc.).
However, you CAN use databound expressions for a textbox or a label, but the amount of work is well, not worth it.
However, in place of a "#" (for data bound controls), you can use "=" for any public exposed function in code behind.
BUT ONLY FOR NON server controls!!!
So,say this public function in code behind:
This works:
<h2><%= MyHotel %></h2>
But, this does not:
<asp:TextBox ID="TextBox1" runat="server"
Text='<%= MyHotel %>'
></asp:TextBox>
(becuase TextBox is a server based control - YOU already have full use in code behind.
However, in place of that above expression, I could just as well do this:
<h2 id="myHeader" runat="server"></h2>
And thus in code behind, do this:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
myHeader.InnerText = MyHotel()
End If
End Sub
So, any public function in the code behind, then use "=", but NOT for built in server side controls - those expression(s) don't work, but then again, you have full use of such controls in code behind anyway.
However, I do see "over and over" like a broken record people "hand coding" the filling out of controls. That makes VERY little sense in this day an age
Hand coding to fill out values from a database into a web page? That sets back the industry to pre-windows days, and before programs like FoxPro, Ms-access etc came out (in which you don't have to hand-code filling out of controls).
Before such programs, lots of "code" generators appeared. Again, kind of messy.
but, with web forms, gridview, listview, datalist view etc. in most cases can do a LOT of the dirty work for you.
However, I just wrote my own "loader" that simple repeats the code we type over and over for each page. I just "made up/cooked up" my own standard.
So, for each control, I just add a "f" attribute (means data colum field).
So, my code takes a given div, loops the controls, and shoves in the database values for me. You write that code one time, and then use it over and over.
So, then I can drop in a div of controls like this:
<div id="EditRecord" runat="server"
style="float: left; display: none" clientidmode="Static">
<br />
<div style="float: left" class="iForm">
<label>HotelName</label>
<asp:TextBox ID="txtHotel" runat="server" f="HotelName" Width="280">
</asp:TextBox>
<br />
<label>First Name</label>
<asp:TextBox ID="tFN" runat="server" f="FirstName" Width="140"></asp:TextBox>
<br />
<label>Last Name</label>
<asp:TextBox ID="tLN" runat="server" f="LastName" Width="140"></asp:TextBox>
<br />
<label>City</label>
<asp:TextBox ID="tCity" runat="server" f="City" Width="140"></asp:TextBox>
<br />
<label>Province</label><asp:TextBox ID="tProvince" runat="server" f="Province" Width="75"></asp:TextBox>
</div>
<div style="float: left; margin-left: 20px" class="iForm">
<div style="float: left">
<label>Description</label>
<br />
<asp:TextBox ID="txtNotes" runat="server" Width="260px" TextMode="MultiLine"
Height="100px" f="Description"></asp:TextBox>
</div>
etc. etc.
So, now to load the above, I do this:
Dim strSQL As String = "SELECT * FROM tblHotelsA WHERE ID = " & intPK
Dim rstData As DataTable = Myrst(strSQL)
' load up our edit div
fLoader(Me.EditRecord, rstData.Rows(0))
ViewState("PK") = intPK
So, this loads the controls for me, and I get this:
the point is I do/did not have to write code over and over to fill out the "div" of controls.
And in above, I have a routine to do the reverse, (take controls, shove back to data table).
So, my save button code then becomes this:
Dim intPK As Integer = ViewState("PK")
Dim strSQL As String = "SELECT * FROM tblHotelsA WHERE ID = " & intPK
Dim rstData As DataTable = Myrst(strSQL)
Call fWriterW(EditRecord, rstData.Rows(0))
Call MyRstSave(rstData, "tblHotelsA")
' re-fresh grid
LoadGrid()
So, I have fLoader (table row to div)
and hten fWriter (div to table)
And then a save routine.
So, the built in databinding is much like a hug, but without the kiss.
It can bind/fill controls for you, but it does not give you the reverse (sending control values back to the database).
I can post the above loader, and writer code. I have both a c#, and vb version.
It just a simple loop, and looks for the "f" tag inside of the passed div, and then fills out the control value from the database column.
I mean, really, writing the same code over and over to fill out controls on a page makes VERY little sense. With just a wee bit more effort, you can make such code "general" and it can be used for any web page.