C＃中IEqualityComparer接口的实现

在用linq写代码时，可能会用到去重的功能。若只是string类型的还好，则可通过如下的代码进行去重：

var testList = (from r in realresultList select r).Distinct<string>().toList<string>();

但若realresultList中包含的是类，则需要对类进行处理。那就用到了IEqualityComparer接口。
具体实现如下：
1、先定义自己的model

	public class QueryCommentModel
    {
    
        public string NurseStation {
     get; set; }
        public string DeptID {
     get; set; }
        public string DeptName {
     get; set; }
        public string PharmacistID {
     get; set; }
        public string PharmacistName {
     get; set; }
        public string OrderCount {
     get; set; }
        public string RightCommentStatus {
     get; set; }
        public string ErrorCommentStatus {
     get; set; }
    }

2、实现接口

	public class QueryCommentModelComparer : IEqualityComparer<QueryCommentModel>
    {
    
        //实现具体的比较逻辑（与实际业务相关）
        public bool Equals(QueryCommentModel x, QueryCommentModel y)
        {
    
            bool checkFlag = true;

            if (Object.ReferenceEquals(x, y))
            {
    
                checkFlag = true;
            }
            else if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))
            {
    
                checkFlag = false;
            }
            else
            {
    
                if (x.NurseStation == y.NurseStation && x.DeptID == y.DeptID && x.PharmacistID == y.PharmacistID)
                {
    
                    checkFlag = true;
                }
                else
                {
    
                    checkFlag = false;
                }
            }

            return checkFlag;
        }

        //实现获取哈希值
        public int GetHashCode(QueryCommentModel model)
        {
    
            if (Object.ReferenceEquals(model, null)) return 0;

            int hashNurse = model.NurseStation.GetHashCode();
            int hashDeptID = model.DeptID.GetHashCode();
            int hashPharmacist = model.PharmacistID.GetHashCode();
            return hashNurse ^ hashDeptID ^ hashPharmacist;
        }
    }

3、在业务代码中实现

//通过比较器，实现类的去重
var testList = (from r in realresultList select r).Distinct<QueryCommentModel>(new QueryCommentModelComparer()).ToList<QueryCommentModel>();