How can i hide a custom column from the DispForm.aspx for my announcment App

Question

I have added a custom column named "Date" inside my announcement list, but i want to hide this column from the DispForm.aspx page. i tried the following two methods to hide the Date column but none of them worked:-

1. inside the DispForm.aspx, i add the following code:-

   <asp:Content ContentPlaceHolderId="PlaceHolderMain" runat="server">
   
   <script type="text/javascript">
      var control = findacontrol("Date");
      control.parentNode.parentNode.style.display="none";
   
   function findacontrol(FieldName) {
      var arr = document.getElementsByTagName("!");
      // get all comments
      for (var i=0;i < arr.length; i++ )
      {
         // now match the field name
         if (arr[i].innerHTML.indexOf(FieldName) > 0)
         {         return arr[i];      }
      }
   }
   

   but it did not hide the Date field.

2. i also try the following power shell script:-

   # First load SharePoint Core Assembly [System.Reflection.Assembly]::LoadWithPartialName(“Microsoft.SharePoint”)

   $url = "http://sharepointdev/";
   $list = "List";
   $fieldname = "Date";
   
   #Setting up context
   $$contextWeb = Get-SPWeb  http://sharepointdev;
   
   $list = $contextWeb.Lists.TryGetList($list);
   $field = $list.Fields[$fieldname];
   
   # Controls Field in Edit Form
   $field.ShowInEditForm = 1;
   # Controls Field in New Form
   $field.ShowInNewForm = 0;
   # Controls Field in New Form
   $field.ShowInDisplayForm = 1;
   # Hides fields from list settings
   $field.ShowInListSettings = 1;
   # Hides fields from version history
   $field.ShowInVersionHistory = 1;
   # Hides fields form selection in views
   $field.ShowInViewForms = 1;
   # Don't forget to update this field
   $field.Update();
   # And finally dispose everything.
   $contextWeb.Dispose();
   $contextSite.Dispose();
   

but i got the following errorinside the power shell window:-

PS C:\Users\Administrator> $list = $contextWeb.Lists.TryGetList($list); You cannot call a method on a null-valued expression. At line:1 char:1 + $list = $contextWeb.Lists.TryGetList($list); + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (:) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull

so can anyone advice on how i can hide the custom column from my announcement APP?

EDIT

Here is the updated code:-

$url = "http://sharepointdev/";
$list = "News & Announcement";
$fieldname = "Date";

#Setting up context
$webApp = Get-SPWebApplication http://sharepointdev

$list = $contextWeb.Lists.TryGetList($list);
$field = $list.Fields[$fieldname];

# Controls Field in Edit Form
$field.ShowInEditForm = 1;
# Controls Field in New Form
$field.ShowInNewForm = 1;
# Controls Field in New Form
$field.ShowInDisplayForm = 0;
# Hides fields from list settings
$field.ShowInListSettings = 1;
# Hides fields from version history
$field.ShowInVersionHistory = 1;
# Hides fields form selection in views
$field.ShowInViewForms = 1;
# Don't forget to update this field
$field.Update();
# And finally dispose everything.
$contextWeb.Dispose();
$contextSite.Dispose();

but it is raising the following error:-

> PS C:\Users\Administrator> $webApp = Get-SPWebApplication
> http://sharepointdev PS C:\Users\Administrator> PS
> C:\Users\Administrator> $list = $contextWeb.Lists.TryGetList($list);
> You cannot call a method on a null-valued expression. At line:1 char:1
> + $list = $contextWeb.Lists.TryGetList($list);
> + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
>     + FullyQualifiedErrorId : InvokeMethodOnNull

Answer 1

The problem is you are using double dollar symbol in $$contextWeb so when you try to use it with one $ symbol the variable is null.

In order to hide the column in DispForm you have to use $field.ShowInDisplayForm = 0 instead of $field.ShowInDisplayForm = 1

Finally, update not only the field $field.Update() but also the list $list.Update()

UPDATED

$url = "http://sharepointdev/";
$fieldname = "Date";

#Setting up context
$web = Get-SPWeb -Identity $url

$list = $web.Lists["InternalNameOfTheList"]
$field = $list.Fields[$fieldname];

# Controls Field in Edit Form
$field.ShowInEditForm = 1;
# Controls Field in New Form
$field.ShowInNewForm = 1;
# Controls Field in New Form
$field.ShowInDisplayForm = 0;
# Hides fields from list settings
$field.ShowInListSettings = 1;
# Hides fields from version history
$field.ShowInVersionHistory = 1;
# Hides fields form selection in views
$field.ShowInViewForms = 1;
# Don't forget to update this field
$field.Update();
    $list.Update();
# And finally dispose everything.
$web.Dispose();

Hope it helps