Semi-regarding this post of mine from several years ago:

I've needed to make some changes so that the total in my datagrid updates when other fields change. This means my workaround (the edit button) goes away, so I am trying to make some modifications to the partial linq to sql class for a view that I use for calculations by implementing INotifyPropertyChanged (I just set the view primary key).
I'm using this as a reference: Calculated column in datagrid WPF I can make this work if I can change the behavior of the PaySum_Total getter in the auto generated class from this:

        public decimal PaySum_Total_Pay
        {
            get
            {
                return this._PaySum_Total_Pay;
            }
            set
            {
                if ((this._PaySum_Total_Pay != value))
                {
                    this.OnPaySum_Total_PayChanging(value);
                    this.SendPropertyChanging();
                    this._PaySum_Total_Pay = value;
                    this.SendPropertyChanged("PaySum_Total_Pay");
                    this.OnPaySum_Total_PayChanged();
                }
            }

to this:

        public decimal PaySum_Total_Pay
        {
            get
            {
                return this.CalcTotalOnChange();
            }
            set
            {
                //same code here from earlier
            }
        }

but of course this gets removed as soon as I make any changes to the dbml. I have created another partial class in another file to provide code for some of the stub methods in the class here:

public partial class Payroll_SummaryReview : INotifyPropertyChanging, INotifyPropertyChanged
    {     
        partial void OnPaySum_Total_AdditionsChanged()
        {
            this.OnPaySum_Total_PayChanged();
        }
        partial void OnPaySum_Total_PayChanged()
        {
            this.SendPropertyChanged("PaySum_Total_Pay");
        }
        partial void OnPaySum_IsApprovedChanged()
        {
            //do something as approved cb changes...?
        }
        //partial void OnPaySum_Reason_DescriptionChanged();
        partial void OnPaySum_MinApprovedChanged()
        {
            CalcTotalOnChange();
            this.SendPropertyChanged("PaySum_Total_Pay");
        }
        partial void OnPaySum_TrainerChanged()
        {
            CalcTotalOnChange();
            this.SendPropertyChanged("PaySum_Total_Pay");
        }
        partial void OnPaySum_OOTChanged()
        {
            CalcTotalOnChange();
            this.SendPropertyChanged("PaySum_Total_Pay");
        }
        partial void OnPaySum_MiscAdditionsChanged()
        {
            CalcTotalOnChange();
            this.SendPropertyChanged("PaySum_Total_Pay");
        }
        partial void OnPaySum_PayCorrectionChanged()
        {
            CalcTotalOnChange();
            this.SendPropertyChanged("PaySum_Total_Pay");
        }
        partial void OnPaySum_CallInLoadPayChanged()
        {
            CalcTotalOnChange();
            this.SendPropertyChanged("PaySum_Total_Pay");
        }
        partial void OnPaySum_CallInPayChanged()
        {
            CalcTotalOnChange();
            this.SendPropertyChanged("PaySum_Total_Pay");
        }


        private decimal CalcTotalOnChange()
        {
            decimal total = 0m;

            decimal minimum = this.PaySum_Shifts ?? 0 * this.Min_Rate;
            bool minOk = (this.PaySum_Total_Extra_Pay ?? 0)   this.PaySum_Total_Load_Pay   (this.PaySum_MiscAdditions ?? 0) < minimum
                && this.PaySum_MinApproved
                && (this.PaySum_Total_Additions == null || this.PaySum_Total_Additions == 0);

            if (minOk) //misc addition inclucisive of minimums.
                this.PaySum_Total_Additions = minimum - (this.PaySum_Total_Extra_Pay ?? 0   this.PaySum_Total_Load_Pay   this.PaySum_MiscAdditions ?? 0);
            else
                this.PaySum_Total_Additions = 0M;
            total = this.PaySum_Total_Extra_Pay ?? 0 
                this.PaySum_Total_Load_Pay  
                this.PaySum_Total_Additions ?? 0  
                this.PaySum_OOT ?? 0  
                this.PaySum_Trainer ?? 0  
                this.PaySum_PayCorrection ?? 0  
                this.PaySum_MiscAdditions ?? 0  
                this.PaySum_CallInLoadPay ?? 0;
            int intMo = this.PaySum_Week_End_Date.Month;
            decimal callInRate = 0M;
            if (intMo > 3 && intMo < 10)
                callInRate = 100M;
            else
                callInRate = 85M;
            total  = (Convert.ToDecimal(this.PaySum_CallInPay) * callInRate);

            //section determines eligibility for and amount of Seniority pay.... but I actually added this to the view so screw this section Payroll_SummaryReview.
            //Need to add source to source control
            this.PaySum_Seniority = total * this.SeniorityPercent ?? 0;

            return = total   this._PaySum_Seniority;
            //PayrollDataContext.SavedSummary = false; //need to set unsaved changes flag in Review somewhow
        }

It looks like I can't override the public decimal PaySum_Total_Pay because of the way Linq generates the property. Is there something else I'm not aware of to make this work? I also would be more than happy to approach this from a different angle but I'm not sure what that angle would be right now, but I would appreciate some help here.

Sorry if this is rambling a bit and ugly code, but still a WIP.

CodePudding user response：

You could implement a default constructor or method in the partial non-autogenrated class that handles the PropertyChanged event (that I assume that the auto-generated SendPropertyChanged method raises), and then update and raise the PropertyChanged event for the PaySum_Total_Pay in the event handler. Something like this:

public partial class Payroll_SummaryReview
{
    public Payroll_SummaryReview()
    {
        this.PropertyChanged  = Payroll_SummaryReview_PropertyChanged;
    }

    private void Payroll_SummaryReview_PropertyChanged(object? sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName != nameof(PaySum_Total_Pay))
        {
            this._PaySum_Total_Pay = ...;
            PropertyChanged?.Invoke(this,
                new PropertyChangedEventArgs(nameof(PaySum_Total_Pay)));
        }
    }
}