c#  Linq distinct不会调用Equals方法详解

public class ModInfo : IEquatable<ModInfo>
{
 public int ID { get; set; }
 public string MD5 { get; set; }

 public bool Equals(ModInfo other)
 {
  return other.MD5.Equals(MD5);
 }

 public override int GetHashCode()
 {
  return MD5.GetHashCode();
 }
}

public void ReloadEverything() {
 var beforeSort = new List<ModInfo>();
 // Bunch of loading from local sqlite database. 
 // not included since it's reload boring to look at
 var modinfo = beforeSort.OrderBy(m => m.ID).AsEnumerable().Distinct().ToList();
}

public override bool Equals(object other)
{
 ModInfo mod = other as ModInfo;
 if (mod != null)
  return Equals(mod);
 return false;
}

public class ModInfo : IEquatable<ModInfo>
{
 public int ID { get; set; }
 public string MD5 { get; set; }

 public bool Equals(ModInfo other)
 {
  if (other == null) return false;
  return (this.MD5.Equals(other.MD5));
 }

 public override int GetHashCode()
 {
  unchecked
  {
   int hash = 13;
   hash = (hash * 7) + MD5.GetHashCode();
   return hash;
  }
 }

 public override bool Equals(object obj)
 {
  ModInfo other = obj as ModInfo;
  if (other != null)
  {
   return Equals(other);
  }
  else
  {
   return false;
  }
 }
}

ModInfo mod1 = new ModInfo {ID = 1, MD5 = "0AAEBF5D2937BDF78CB65807C0DC047C"};
ModInfo mod2 = new ModInfo {ID = 2, MD5 = "0AAEBF5D2937BDF78CB65807C0DC047C"};

// You should get true here
bool areEqual = mod1.Equals(mod2);

List<ModInfo> mods = new List<ModInfo> {mod1, mod2};

// You should get 1 result here
mods = mods.Distinct().ToList();

List testList = new List<ConsoleApplication1.TestModel>();
testList.Add(new TestModel()
{
Index=1,
Name=“Index1”
});
testList.Add(new TestModel()
{
Index = 2,
Name = “Index2”
});
testList.Add(new TestModel()
{
Index = 2,
Name = “Index2”
});
testList = testList.Distinct().ToList();