Can't set value of Label with QueryString

Question

User-242390214 posted

Hi All

I'm having trouble with something that I thought should be pretty straighforwards...

I'm trying to set the value of a Label with the value from a QueryString. Here's what I'm doing:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim QS As String = Request.QueryString("MenuLinkID")
        Dim myLabel As Label = TryCast(DetailsView1.FindControl("Label2"), Label)
        Response.Write(QS)

        myLabel.Text = QS

    End Sub

I definitely get the right value from the QueryString as seen in the response.write(QS)

And if I put:

myLabel.Text = "Hello World" - that works too.

Weird.

What am I missing?

Answer 1

User-311685349 posted

You should just be able to do

Label2.Text = Request.QueryString("MenuLinkID")

Answer 2

User-242390214 posted

I wish!

My Label is within a DetailsView, so I have to use FindControl.

I shortened to this:

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Dim myLabel As Label = TryCast(DetailsView1.FindControl("Label2"), Label)

        myLabel.Text = Request.QueryString("MenuLinkID")



    End Sub

Nothing comes up - yet I can still put myLabel.Text = "Hello World" and it pops up, no problem.

I can response.write(MenuLinkID) too...

How weird is that?!

Answer 3

User-242390214 posted

This works:

                myLabel.Text = "8"

And this:

               Dim QS = "Hello World?"

               myLabel.Text = QS

But not this:

              Dim QS = Request.QueryString("MenuLinkID")

              myLabel.Text = QS

Answer 4

User-311685349 posted

If you set a breakpoint on myLabel.Text = QS

what does QS contain? 

Answer 5

User-242390214 posted

It says:

     QS    Nothing    String

But presumably this is because the referring page hasn't been activated right?

Not used break points before, so not sure how this helps...

Answer 6

User-242390214 posted

Ok, the debugger seems to work running from the referring page... cool (newb!)

Anyway, it says the same thing - QS Nothing String

However, when I click continue, the response.write value is written and correct.

So, is there something wrong with trying to change the value of the Label/Textbox control with the PageLoad event?

Answer 7

User-311685349 posted

What if you did a

myLabel.Text = Request.QueryString("MenuLinkID")

I shouldn't be to do with the label... maybe the response.write is clearning the variable???  But I doubt it 

Answer 8

User-242390214 posted

Hi Andrew

Thanks for the info.

In the end, I rebuilt the page from scratch and it worked as intended. I'm not sure what happened to the original file but it must have been corrupt somehow. Anyway, there's probably a moral to that story...