Question

我有以下测试示例：

var a = new List<OrderRule> {
  new OrderRule("name", OrderDirection.Ascending),
  new OrderRule("age", OrderDirection.Descending)
};

var b = new List<OrderRule> {
  new OrderRule("name", OrderDirection.Ascending),
  new OrderRule("age", OrderDirection.Descending)
};

var r = a.SequenceEqual(b);
Assert.Equal(a, b);

变量r为true但Assert.Equal为false ...

OrderRule类如下：

public class OrderRule : IEquatable<OrderRule> {

  public OrderDirection Direction { get; }
  public String Property { get; }

  public OrderRule(String property, OrderDirection direction) {
    Direction = direction;
    Property = property;
  }

  public Boolean Equals(OrderRule other) {
    if (other == null)
      return false;
    return Property.Equals(other.Property) && Direction.Equals(other.Direction);  
  }

  public override Boolean Equals(Object obj) {  
    if (ReferenceEquals(null, obj))
      return false;
    if (ReferenceEquals(this, obj))
      return true;
    if (obj.GetType() != GetType())
      return false;
    return Equals(obj as IncludeRule);
  }

  public override Int32 GetHashCode() {
    return HashCode.Of(Property).And(Direction);
  }
}

public enum OrderDirection { ASC, DESC }

当重写Equals并实现IEquatable时，Assert.Equal是否有任何问题？

UPDATE - HashCode帮助

public struct HashCode {

  private readonly Int32 Value;

  private HashCode(Int32 value) {
    Value = value;
  }

  public static implicit operator Int32(HashCode hashCode) {
    return hashCode.Value;
  }

  public static HashCode Of<T>(T item) {
    return new HashCode(GetHashCode(item));
  }

  public HashCode And<T>(T item) {
    return new HashCode(CombineHashCodes(Value, GetHashCode(item)));
  }

  public HashCode AndEach<T>(IEnumerable<T> items) {      
    Int32 hashCode = items.Select(x => GetHashCode(x)).Aggregate((x, y) => CombineHashCodes(x, y));
    return new HashCode(CombineHashCodes(Value, hashCode));
  }

  private static Int32 CombineHashCodes(Int32 x, Int32 y) {
    unchecked {        
      return ((x << 5) + x) ^ y;
    }  
  }

  private static Int32 GetHashCode<T>(T item) {
    return item == null ? 0 : item.GetHashCode();
  }

}

Answer 1

您的代码在我这边按预期工作。我只修复了编译错误 - IncludeRule已更改为OrderRule中的Equals，还修复了OrderDirection枚举成员。

当Object实现IEquatable时，Equal Collection返回false？

1 个答案: