How to get HiddenField control in Masterpage and set it's value?

Question

I have a MasterPage that contains a hidden field control. I want to get the current value of the hidden field and set the value of it from pages that use the MasterPage.

I have the following code so far: (in one of the pages)

   //Get the textbox and set it's value
   TextBox txt1 = new TextBox();
                txt1 = (TextBox)this.Master.FindControl("txtHiddenField");
                txt1 .Text = "true";

The above code does not seem to work. What code would I need to get the hidden field control and set it's value? (and get it's value)

is txtHiddenField a HiddenField? then use HiddenField type. You don't need to use a constructor at all, why should I create an instance to get a reference to another instance? — Adrian Iftode, Apr 27 '12 at 09:50
I guess it should be as ((TextBox)this.Master.FindControl("txtHiddenField")).Text = "True"; — Rajesh, Apr 27 '12 at 10:04

Tim Schmelter · Accepted Answer · 2012-04-27T10:01:31.323

I would recommend to provide a public property/method in your MasterPage, that you can use to set/get the HiddenField's value.

in your Master(assuming it's type is called SiteMaster):

public String HiddenValue { 
    get{return txtHiddenField.Value;}
    set{txtHiddenField.Value = value;}
}

In your page:

SiteMaster master = (SiteMaster)Page.Master;
master.HiddenValue = "true";

This approach is straight-forward, less prone to errors and easily readable. You could even change the control in your master without needing to change the pages(f.e. if you want to replace the hidden-field with a TextBox).

Assuming that your "true" value indicates that you actually want to store a boolean, i would recommend to use a bool as data-type for the property and a self-explanatory name. Then you can store it in the hiddenfield but the client(the page) does not need to know.

score 2 · Answer 2 · answered Apr 27 '12 at 09:53

2

HiddenField sets its text as VALUE, while TextBox has a TEXT property. Of course casting one to the other and setting text property won't help.

Do this instead:

HiddenField hiddenField = (HiddenField)Master.FindControl("txtHiddenField");
hiddenField.Value = "true";

answered Apr 27 '12 at 09:53

walther

13,466
5
41
67

It doesn't seem to find the field. hiddenField = null. What reasons could there be for this? – Theomax Apr 27 '12 at 10:06

score 1 · Answer 3 · answered Apr 27 '12 at 09:52

1

Assuming you have added hidden field control like this ->>

<input type="hidden" ID="hiddenFieldID" runat="server" />

you can access it like -->>

HtmlInputHidden hiddenfield = (HtmlInputHidden)this.Master.FindControl(

answered Apr 27 '12 at 09:52

rt2800

3,045
2
19
26

score 1 · Answer 4 · answered Apr 27 '12 at 09:54

May be you are missing ContentPlaceHolder

Try something like this

  ContentPlaceHolder mpContentPlaceHolder;
    TextBox mpTextBox;
    mpContentPlaceHolder = 
      (ContentPlaceHolder)Master.FindControl("ContentPlaceHolder1");
    if(mpContentPlaceHolder != null)
    {
        mpTextBox = 
            (TextBox) mpContentPlaceHolder.FindControl("TextBox1");
        if(mpTextBox != null)
        {
            mpTextBox.Text = "TextBox found!";
        }
    }

Read more about Reference ASP.NET Master Page Content

How to get HiddenField control in Masterpage and set it's value?

4 Answers4

Linked