覆盖C＃的GetHashCode（），尽管字段不同，但返回相同的哈希值

Question

我为我的一个对象覆盖了GetHashCode()。我的代码将从本地数据库检索一个副本，并从第三方端点检索另一个副本。

我已经看完下面的代码，可以看到我在处理过程中有各自不同的哈希值，但是两个对象的总体哈希返回相同。

例如，当我获得对象的第三方版本时，而DB版本具有有效的GUID，则SubscriptionId默认为00000000-0000-0000-0000-000000000000。发生了什么事？

public partial class ImportSubscriptionRatePlanCharge
{
    public override int GetHashCode()
    {
        unchecked // Overflow is fine, just wrap
        {
            int hash = 17;
            // Suitable nullity checks etc, of course :)
            hash = hash * 23 + SubscriptionId.GetSafeHashCode();
            hash = hash * 23 + SubscriptionRatePlanId.GetSafeHashCode();
            hash = hash * 23 + SubscriptionRatePlanChargeId.GetSafeHashCode();
            hash = hash * 23 + OriginalChargeId.GetSafeHashCode();
            hash = hash * 23 + ProductRatePlanChargeId.GetSafeHashCode();
            hash = hash * 23 + Number.GetSafeHashCode();
            hash = hash * 23 + Name.GetSafeHashCode();
            hash = hash * 23 + Type.GetSafeHashCode();
            hash = hash * 23 + Model.GetSafeHashCode();
            hash = hash * 23 + Uom.GetSafeHashCode();
            hash = hash * 23 + Version.GetSafeHashCode();
            hash = hash * 23 + PricingSummary.GetSafeHashCode();
            hash = hash * 23 + PriceChangeOption.GetSafeHashCode();
            hash = hash * 23 + PriceIncreasePercentage.GetSafeHashCode();
            hash = hash * 23 + Currency.GetSafeHashCode();
            hash = hash * 23 + Price.GetSafeHashCode();
            hash = hash * 23 + Tiers.GetSafeHashCode();
            hash = hash * 23 + IncludedUnits.GetSafeHashCode();
            hash = hash * 23 + OveragePrice.GetSafeHashCode();
            hash = hash * 23 + DiscountPercentage.GetSafeHashCode();
            hash = hash * 23 + DiscountAmount.GetSafeHashCode();
            hash = hash * 23 + ApplyDiscountTo.GetSafeHashCode();
            hash = hash * 23 + DiscountLevel.GetSafeHashCode();
            hash = hash * 23 + DiscountClass.GetSafeHashCode();
            hash = hash * 23 + BillingDay.GetSafeHashCode();
            hash = hash * 23 + ListPriceBase.GetSafeHashCode();
            hash = hash * 23 + BillingPeriod.GetSafeHashCode();
            hash = hash * 23 + SpecificBillingPeriod.GetSafeHashCode();
            hash = hash * 23 + BillingTiming.GetSafeHashCode();
            hash = hash * 23 + BillingPeriodAlignment.GetSafeHashCode();
            hash = hash * 23 + Quantity.GetSafeHashCode();
            hash = hash * 23 + SmoothingModel.GetSafeHashCode();
            hash = hash * 23 + NumberOfPeriods.GetSafeHashCode();
            hash = hash * 23 + OverageCalculationOption.GetSafeHashCode();
            hash = hash * 23 + OverageUnusedUnitsCreditOption.GetSafeHashCode();
            hash = hash * 23 + UnusedUnitsCreditRates.GetSafeHashCode();
            hash = hash * 23 + UsageRecordRatingOption.GetSafeHashCode();
            hash = hash * 23 + Segment.GetSafeHashCode();
            hash = hash * 23 + EffectiveStartDate.GetSafeHashCode();
            hash = hash * 23 + EffectiveEndDate.GetSafeHashCode();
            hash = hash * 23 + ProcessedThroughDate.GetSafeHashCode();
            hash = hash * 23 + ChargedThroughDate.GetSafeHashCode();
            hash = hash * 23 + Done.GetHashCode();
            hash = hash * 23 + TriggerDate.GetSafeHashCode();
            hash = hash * 23 + TriggerEvent.GetSafeHashCode();
            hash = hash * 23 + EndDateCondition.GetSafeHashCode();
            hash = hash * 23 + UpToPeriodsType.GetSafeHashCode();
            hash = hash * 23 + UpToPeriods.GetSafeHashCode();
            hash = hash * 23 + SpecificEndDate.GetSafeHashCode();
            hash = hash * 23 + Mrr.GetSafeHashCode();
            hash = hash * 23 + Dmrc.GetSafeHashCode();
            hash = hash * 23 + Tcv.GetSafeHashCode();
            hash = hash * 23 + Dtcv.GetSafeHashCode();
            hash = hash * 23 + Description.GetSafeHashCode();

            return hash;
        }
    }
    public override bool Equals(object obj)
    {
        if (!(obj is ImportSubscriptionRatePlanCharge target)
            || this.SubscriptionId != target.SubscriptionId
            || this.SubscriptionRatePlanId != target.SubscriptionRatePlanId
            || this.SubscriptionRatePlanChargeId != target.SubscriptionRatePlanChargeId)
            return false;

        return this.OriginalChargeId == target.OriginalChargeId
            && this.ProductRatePlanChargeId == target.ProductRatePlanChargeId
            && this.Number == target.Number
            && this.Name == target.Name
            && this.Type == target.Type
            && this.Model == target.Model
            && this.Uom == target.Uom
            && this.Version == target.Version
            && this.PricingSummary == target.PricingSummary
            && this.PriceChangeOption == target.PriceChangeOption
            && this.PriceIncreasePercentage == target.PriceIncreasePercentage
            && this.Currency == target.Currency
            && this.Price == target.Price
            && this.Tiers == target.Tiers
            && this.IncludedUnits == target.IncludedUnits
            && this.OveragePrice == target.OveragePrice
            && this.DiscountPercentage == target.DiscountPercentage
            && this.DiscountAmount == target.DiscountAmount
            && this.ApplyDiscountTo == target.ApplyDiscountTo
            && this.DiscountLevel == target.DiscountLevel
            && this.DiscountClass == target.DiscountClass
            && this.BillingDay == target.BillingDay
            && this.ListPriceBase == target.ListPriceBase
            && this.BillingPeriod == target.BillingPeriod
            && this.SpecificBillingPeriod == target.SpecificBillingPeriod
            && this.BillingTiming == target.BillingTiming
            && this.BillingPeriodAlignment == target.BillingPeriodAlignment
            && this.Quantity == target.Quantity
            && this.SmoothingModel == target.SmoothingModel
            && this.NumberOfPeriods == target.NumberOfPeriods
            && this.OverageCalculationOption == target.OverageCalculationOption
            && this.OverageUnusedUnitsCreditOption == target.OverageUnusedUnitsCreditOption
            && this.UnusedUnitsCreditRates == target.UnusedUnitsCreditRates
            && this.UsageRecordRatingOption == target.UsageRecordRatingOption
            && this.Segment == target.Segment
            && this.EffectiveStartDate == target.EffectiveStartDate
            && this.EffectiveEndDate == target.EffectiveEndDate
            && this.ProcessedThroughDate == target.ProcessedThroughDate
            && this.ChargedThroughDate == target.ChargedThroughDate
            && this.Done == target.Done
            && this.TriggerDate == target.TriggerDate
            && this.TriggerEvent == target.TriggerEvent
            && this.EndDateCondition == target.EndDateCondition
            && this.Name == target.UpToPeriodsType
            && this.UpToPeriods == target.UpToPeriods
            && this.SpecificEndDate == target.SpecificEndDate
            && this.Mrr == target.Mrr
            && this.Mrr == target.Dmrc
            && this.Tcv == target.Tcv
            && this.Dtcv == target.Dtcv
            && this.Description == target.Description;
    }
}