CODEWITHSUNDEEP
c#asp.net
Steve B
Steve B

Reputation: 37660

The visible property of a Label act as read only

I have a label within a user control:

<asp:Label runat="server" ID="lblRemainingPlacesMessage" Visible="false" />

I want to setup its visibility to true:

protected void Page_Load(object sender, EventArgs e) {
    lblRemainingPlacesMessage.Visible = true;
}

However, the label is still hidden.

What's is puzzling me, is that the property can't be changed, even in the immediate window, or the debugger local watch:

(immediate window)

lblRemainingPlacesMessage.Visible
false
lblRemainingPlacesMessage.Visible = true
true
lblRemainingPlacesMessage.Visible
false

What can explain that my Visible property can't be changed?

I have no exception. Just a NOOP like operation...

My app has the viewstate enabled. Most of all, I have other label in the page, that works perfectly!

Don't know if its matter, but I dynamically instantiate my user control within my owner page using:

    protected override void CreateChildControls()
    {
        m_VisualControl = (MyUserControl)Page.LoadControl(_ascxPath);
        Controls.Add(m_VisualControl);
    }

The app uses ASP.Net WebForms with .net 3.5 SP1, and I use Visual Studio 2012 Premium.

Upvotes: 3

Views: 2040

Answers (2)

Steve B
Steve B

Reputation: 37660

Yuriy Galanter's comment put me on the right track.

Simply, my immediate parent was not visible. And I suppose the visible property of a control combines the control ancestors visibility.

Sometimes simple problem have simple resolution :)

Upvotes: 1

Fals
Fals

Reputation: 6839

1) You should create any dynamic UserControl at OnInit or you will not be able to use ViewState:

2) Expose the label property that you wan't to change as property of the UserControl

public bool HiddeMyLabel
{
   set { lblRemainingPlacesMessage.Visible = value; }
   get { lblRemainingPlacesMessage.Visible; }
}

3) You should ever use OnPreRender from the page to change any control property.

protected override void OnPreRender(EventArgs e)
{
    MyUserControl.HiddeMyLabel = false; 
}

4) If you still having issues, remove the hidden attribute manually:

public bool HiddeMyLabel
{
   set 
   { 
     if(value)
       lblRemainingPlacesMessage.Attributes.Add("style", "display:none");
     else
       lblRemainingPlacesMessage.Attributes.Add("style", "display:block");
   }
}

Upvotes: 0

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