Adding Currency Conversion To Screen

Thanks for the help 
I was able to figure the entire cycle. This may help someone 😉 . The currency pxa:Currency requires that you set the effective date and rate type (spot, etc) which is done use the event handlers in BLC and ToggleCurrency
 

The DAC

class GTItems 
{
         #region CuryInfoID
        [PXDBLong]
        [CurrencyInfo]
        public virtual long? CuryInfoID { get; set; }
        public abstract class curyInfoID : PX.Data.BQL.BqlLong.Field<curyInfoID> { }
        #endregion

     #region CuryId
     [PXDBString(5, IsUnicode = true, InputMask = ">LLLLL")]
     [PXUIField(DisplayName = "Currency", Enabled = false)]             
    [PXUIField(DisplayName = "Currency ID")]

        public virtual string CuryID { get; set; }
    #endregion

        #region ItemAmt
        [PXDBBaseCury]
        [PXDefault(TypeCode.Decimal, "0.0")]
        public virtual Decimal? ItemAmt { get; set; }
        public abstract class ItemAmt : PX.Data.BQL.BqlDecimal.Field<ItemAmt> { }
        #endregion

        #region CuryItemAmt
        [PXUIField(DisplayName = "Item Amount", Enabled = false, Visibility = PXUIVisibility.Visible)]
        [PXDBCurrency(typeof(curyInfoID), typeof(ItemAmt))]
        [PXDefault(TypeCode.Decimal, "0.0")]
        public virtual Decimal? CuryItemAmt { get; set; }
        public abstract class curyItemAmt : PX.Data.BQL.BqlDecimal.Field<curyItemAmt> { }
        #endregion
}

The graph contains  view of the currencyinfo, event handler and events for add effdate

The Graph
public class ItemsMaint : PXGraph<ItemsMaint, GTItems>
{
     public PXSelect<GTItems> Items;
     public PXSelect<CurrencyInfo, Where<CurrencyInfo.curyInfoID,  Equal<Current<GTItems.curyInfoID>>>> currencyinfo;

     public ToggleCurrency<GTItems> CurrencyView;

        #region CurrencyInfo Events

        protected virtual void _(Events.FieldDefaulting<CurrencyInfo, CurrencyInfo.curyID> e)
        {
            if (PXAccess.FeatureInstalled<FeaturesSet.multicurrency>())
            {
                if (Accessinfo.BaseCuryID != null )
                {
                    e.NewValue = Accessinfo.BaseCuryID;
                    e.Cancel = true;
            }
        }

        protected virtual void _(Events.FieldDefaulting<CurrencyInfo, CurrencyInfo.curyRateTypeID> e)
        {
            if (PXAccess.FeatureInstalled<FeaturesSet.multicurrency>())
            {     

              if( Accessinfo.CuryRateID != null)
                {
                       e.NewValue = Accessinfo.CuryRateID;
                       e.Cancel = true; 
                } else {
                     e.NewValue = "SPOT";
                      e.Cancel = true;  
             }

            }
        }

        protected virtual void _(Events.FieldDefaulting<CurrencyInfo, CurrencyInfo.curyEffDate> e)
        {
                e.NewValue = DateTime.UtcNow;
                e.Cancel = true;
            
        }

        protected virtual void _(Events.RowSelected<CurrencyInfo> e)
        {
            CurrencyInfo info = e.Row as CurrencyInfo;
            if (info != null)
            {
                bool curyenabled = info.AllowUpdate(this.Lines.Cache);

                PXUIFieldAttribute.SetEnabled<CurrencyInfo.curyRateTypeID>(e.Cache, info, curyenabled);
                PXUIFieldAttribute.SetEnabled<CurrencyInfo.curyEffDate>(e.Cache, info, curyenabled);
                PXUIFieldAttribute.SetEnabled<CurrencyInfo.sampleCuryRate>(e.Cache, info, curyenabled);
                PXUIFieldAttribute.SetEnabled<CurrencyInfo.sampleRecipRate>(e.Cache, info, curyenabled);
            }
        }
        #endregion

}

In the ASPX 

In a PXFormView 

<pxa:PXCurrencyRate DataField="CuryID" ID="edCury" runat="server" RateTypeView="currencyinfo"    DataMember="_Currency_"></pxa:PXCurrencyRate>

In PXDataSource 

<CallbackCommands>
            <px:PXDSCallbackCommand Visible="False" Name="CurrencyView" />
</CallbackCommands>