ToggleListAsEntryPoints.cs

using System;
using PX.Objects;
using PX.Data;

namespace PX.Data
{
  public class LEPMaint_Extension : PXGraphExtension<LEPMaint>
  {
    #region Event Handlers
    public PXAction<PX.Data.ListEntryPoint> ToggleActivation;
  
    [PXButton(CommitChanges = true)]
    [PXUIField(DisplayName = "Toggle Activation")]
    protected void toggleActivation()
    {
      ListEntryPoint first = Base.Items.Select();
      if(first  != null)
      {
        bool val = !first.IsActive ?? false;
        
        foreach(ListEntryPoint row in Base.Items.Select())
        {
          row.IsActive = val;
          Base.Items.Update(row);      
        }
      }
    }
    #endregion
  }
}