You've got several options:
- Implement IEquatable<T> on the type
DNS_Log
- Override Equals and GetHashCode without implementing
IEquatable<T>
- Implement a separate IEqualityComparer<T> and pass it to Distinct
NOTE! In all the code below, the equality check assumes that the ==
operator knows how to deal with each type. That is certainly true for the DateTime member (assuming it is of type DateTime as well), but I obviously cannot guarantee that the others will work. If the Destination member holds a type for which the ==
operator has not been defined, this is likely to do the wrong thing. Since you haven't posted your own code for this comparer implementation, it's impossible to know what to do here.
IEquatable<T>
public class DNS_Log : IEquatable<DNS_Log>
{
public bool Equals(DNS_Log other)
{
if (other == null)
return false;
return (other.Destination == Destination
&& other.Source_IP == Source_IP
&& other.Domain_Controller == Domain_Controller
&& other.DateTime == DateTime);
}
public override int GetHashCode()
{
int hash = 23;
hash = hash * 59 + (Destination == null ? 0 : Destination.GetHashCode());
hash = hash * 59 + (Source_IP == null ? 0 : Source_IP.GetHashCode());
hash = hash * 59 + (Domain_Controller == null ? 0 : Domain_Controller.GetHashCode());
hash = hash * 59 + DateTime.GetHashCode();
return hash;
}
}
Overriding Equals and GetHashCode without the interface
public class DNS_Log
{
public override bool Equals(object obj)
{
if (obj == null) return false;
var other = obj as DNS_Log;
if (other == null) return false;
... rest the same as above
Separate IEqualityComparer<T>
Lastly, you can provide an IEqualityComparer<T> when calling Distinct
:
dnsLogs = dnsLogs.Distinct(new DNS_LogEqualityComparer()).ToList();
public class DNS_LogEqualityComparer : IEqualityComparer<DNS_Log>
{
public int GetHashCode(DNS_Log obj)
{
int hash = 23;
hash = hash * 59 + (obj.Destination == null ? 0 : obj.Destination.GetHashCode());
hash = hash * 59 + (obj.Source_IP == null ? 0 : obj.Source_IP.GetHashCode());
hash = hash * 59 + (obj.Domain_Controller == null ? 0 : obj.Domain_Controller.GetHashCode());
hash = hash * 59 + obj.DateTime.GetHashCode();
return hash;
}
public bool Equals(DNS_Log x, DNS_Log y)
{
if (ReferenceEquals(x, y)) return true;
if (x == null) return false;
return (x.Destination == y.Destination
&& x.Source_IP == y.Source_IP
&& .Domain_Controller == y.Domain_Controller
&& x.DateTime == y.DateTime);
}
}