まず、私は私のお金のオブジェクトを作成するには、このチュートリアルに従っ:https://www.codeproject.com/articles/837791/money-patternカスタムオブジェクトをLinQで合計するにはどうすればよいですか?
Money totalItems = _invoice.InvoiceDetails
.Sum(y => y.Amount); // Amount is of type Money
私はy.Amount
にコンパイル例外が出ます:「?長い」
は、暗黙的にタイプ 「マネー」を変換できません。ブロック内 のいくつかの戻り値の型が デリゲートの戻り値の型私が間違っているのは何
に暗黙的に変換されないため、意図したデリゲート型にラムダ式を変換しませ することはできますか?ここで
は私のお金のクラスです:おそらく
public class Money
{
public decimal Amount { get; private set; }
public CurrencyCode Currency { get; private set; }
#region Constructors
public Money() { }
public Money(Money amount)
{
this.Amount = amount.Amount;
this.Currency = amount.Currency;
}
public Money(decimal amount, CurrencyCode currencyCode)
{
this.Amount = amount;
this.Currency = currencyCode;
}
public Money(int amount, CurrencyCode currency)
: this(Convert.ToDecimal(amount), currency)
{
}
public Money(double amount, CurrencyCode currency)
: this(Convert.ToDecimal(amount), currency)
{
}
#endregion
#region Comprasion operators
public static bool operator ==(Money var1, Money var2)
{
if ((object)var1 == null || (object)var2 == null)
return false;
if (var1.Currency != var2.Currency) return false;
return var1.Amount == var2.Amount;
}
public static bool operator !=(Money var1, Money var2)
{
return !(var1 == var2);
}
public static bool operator >(Money var1, Money var2)
{
if (var1.Currency != var2.Currency)
throw new InvalidOperationException("Comprasion between different currencies is not allowed.");
return var1.Amount > var2.Amount;
}
public static bool operator <(Money var1, Money var2)
{
if (var1 == var2) return false;
return !(var1 > var2);
}
public static bool operator <=(Money var1, Money var2)
{
if (var1 < var2 || var1 == var2) return true;
return false;
}
public static bool operator >=(Money var1, Money var2)
{
if (var1 > var2 || var1 == var2) return true;
return false;
}
#endregion
#region Ariphmetical operations
public static Money operator +(Money var1, Money var2)
{
if (var1.Currency != var2.Currency)
{
throw new InvalidCastException("Calculation is using different currencies!");
}
return new Money(var1.Amount + var2.Amount, var1.Currency);
}
public static Money operator -(Money var1, Money var2)
{
if (var1.Currency != var2.Currency)
{
throw new InvalidCastException("Calculation is using different currencies!");
}
return new Money(var1.Amount - var2.Amount, var1.Currency);
}
public static Money operator *(Money var1, Money var2)
{
if (var1.Currency != var2.Currency)
{
throw new InvalidCastException("Calculation is using different currencies!");
}
return new Money(var1.Amount * var2.Amount, var1.Currency);
}
public static Money operator /(Money var1, Money var2)
{
if (var1.Currency != var2.Currency)
{
throw new InvalidCastException("Calculation is using different currencies!");
}
return new Money(var1.Amount/var2.Amount, var1.Currency);
}
public static Money operator *(decimal var1, Money var2)
{
return new Money(var1 * var2.Amount, var2.Currency);
}
public static Money operator *(Money var1, decimal var2)
{
return new Money(var1.Amount * var2, var1.Currency);
}
public static Money operator /(decimal var1, Money var2)
{
return new Money(var1/var2.Amount, var2.Currency);
}
public static Money operator /(Money var1, decimal var2)
{
return new Money(var1.Amount/var2, var1.Currency);
}
public static Money operator *(int var1, Money var2)
{
return new Money(var1 * var2.Amount, var2.Currency);
}
public static Money operator *(Money var1, int var2)
{
return new Money(var1.Amount * var2, var1.Currency);
}
public static Money operator /(int var1, Money var2)
{
return new Money(var1/var2.Amount, var2.Currency);
}
public static Money operator /(Money var1, int var2)
{
return new Money(var1.Amount/var2, var1.Currency);
}
public static Money operator *(long var1, Money var2)
{
return new Money(var1 * var2.Amount, var2.Currency);
}
public static Money operator *(Money var1, long var2)
{
return new Money(var1.Amount * var2, var1.Currency);
}
public static Money operator /(long var1, Money var2)
{
return new Money(var1/var2.Amount, var2.Currency);
}
public static Money operator /(Money var1, long var2)
{
return new Money(var1.Amount/var2, var1.Currency);
}
#endregion
public override bool Equals(object obj)
{
if (obj == null) return false;
Money money = obj as Money;
return (this.Amount == money.Amount && this.Currency == money.Currency);
}
public bool Equals(Money money)
{
if ((object)money == null) return false;
return (this.Amount == money.Amount && this.Currency == money.Currency);
}
public override int GetHashCode()
{
return base.GetHashCode();
}
public override string ToString()
{
return this.Amount.ToString();
}
#endregion
y.Amount.Amountを試しますか? – shole
@shole本当に?はい、もちろんですが、私はMoneyクラスのすべての利点を失っています。 –
私はあなたの質問の全体的な点を逃しています、あなたは演算子をオーバーライドしようとしていて、LINQにMoneyの合計をさせようとしています(y.AmountはMoneyです...それは混乱しています!!)。お手伝いしますか? http://stackoverflow.com/questions/17717858/linq-sum-on-objects – shole