.netFramework 升级NetCore 问题汇总及解决方案

升级版本：

NetCore sdk 2.2.108 、AspNetCore 2.2.0、EFCore 2.2.6

所有程序引用均从NuGet上下载，并支持NetCore

问题：

问题1：No coercion operator is defined between types 'System.Int16' and 'System.Boolean'（mysql 数据库类型转化中int16 byte bool 转化问题）

解决方案：

引用 Pomelo.EntityFreamworkCore.Mysql 2.2.0 代替 MySql.Data.EntityFrameworkCore

问题2：Error generated for warning 'Microsoft.EntityFrameworkCore.Database.Transaction.AmbientTransactionWarning: An ambient transaction has been detected. The current provider does not support ambient transactions.（环境事务、分布式事务问题）

解决方案：

因为Pomelo.EFCore.Mysql 2.2.0 不支持TransactionScope

所以采用 using (var scope = DataContextFactory.GetDataContext().Database.BeginTransaction(System.Data.IsolationLevel.RepeatableRead)) 或者

using (var scope = new CommittableTransaction()) 这两种事务代替

问题3：HttpResponseMessage 问题

解决方案：

两个解决方案，建议第一个

1：改为File()返回 2：添加引用并在startup里注册 services.AddMvc().AddWebApiConventions();

问题4：依赖问题

解决方案：采用Autofac4.9.3 版本支持NetCore

问题5：模型转换 Model 不支持static

解决方案：将之前的代码改为第二个里面的，并在调用的地方统一实例化

        public center_flow CenterFlowDto_to_CenterFlow(CenterFlowDto dto)
        {
            var mapper = CreateMap<CenterFlowDto, center_flow>();

            return mapper.Map<CenterFlowDto, center_flow>(dto);
        }

/// <summary>
        /// 险别列表
        /// </summary>
        /// <param name="list"></param>
        /// <returns></returns>
        public List<compensate_insurance> CompensateInsuranceDtoList_to_EntityList(List<CompensateInsuranceDto> list)
        {
            //var mapper = CreateMap<CompensateAdjustmentDto, compensate_adjustment>();
            //return mapper.Map<List<CompensateInsuranceDto>, List<compensate_insurance>>(list);

            var config = new MapperConfiguration(cfg => { cfg.CreateMap<List<CompensateInsuranceDto>, List<compensate_insurance>>(); });
            var mapper = config.CreateMapper();

            return mapper.Map<List<CompensateInsuranceDto>, List<compensate_insurance>>(list);
        }

帮助类：SqlQuery<T>

  1 public static class DataContextExtend
  2     {
  3         public static List<T> SqlQuery<T>(this DatabaseFacade facade, string sql, params object[] parameters)
  4         {
  5             using (var conn = new MySqlConnection(facade.GetDbConnection().ConnectionString))
  6             {
  7                 conn.Open();
  8                 var ds = new DataSet();
  9                 using (var da = new MySqlDataAdapter(sql, conn.ConnectionString))
 10                 {
 11                     if (parameters.Any())
 12                     {
 13                         da.SelectCommand.Parameters.AddRange(parameters);
 14                     }
 15                     da.Fill(ds);
 16                 }
 17 
 18                 conn.Close();
 19                 if (ds.Tables.Count > 0)
 20                 {
 21                     return ToDataList<T>(ds.Tables[0]);
 22                 }
 23                 else
 24                 {
 25                     return new List<T>();
 26                 }
 27             }
 28         }
 29         /// <summary>
 30         /// 返回首行首列
 31         /// </summary>
 32         /// <typeparam name="T"></typeparam>
 33         /// <param name="facade"></param>
 34         /// <param name="sql"></param>
 35         /// <param name="parameters"></param>
 36         /// <returns></returns>
 37         public static T SqlCount<T>(this DatabaseFacade facade, string sql, params object[] parameters)
 38         {
 39             using (var conn = new MySqlConnection(facade.GetDbConnection().ConnectionString))
 40             {
 41                 conn.Open();
 42                 T result;
 43                 var ds = new DataSet();
 44 
 45                 using (var commend = new MySqlCommand(sql, conn))
 46                 {
 47                     if (parameters.Any())
 48                         commend.Parameters.AddRange(parameters);
 49                     result = (T)commend.ExecuteScalar();
 50                 }
 51 
 52                 conn.Close();
 53 
 54                 return result;
 55 
 56             }
 57 
 58         }
 59 
 60 
 61         /// <summary>
 62         /// DataTable转成List
 63         /// </summary>
 64         /// <typeparam name="T"></typeparam>
 65         /// <param name="dt"></param>
 66         /// <returns></returns>
 67         public static List<T> ToDataList<T>(this DataTable dt)
 68         {
 69             var list = new List<T>();
 70             var plist = new List<PropertyInfo>(typeof(T).GetProperties());
 71             if (typeof(T) == typeof(string))
 72             {
 73                 foreach (DataRow givenObject in dt.Rows)
 74                 {
 75                     for (int i = 0; i < dt.Columns.Count; i++)
 76                     {
 77                         if (givenObject[i] != DBNull.Value && givenObject[i] != null)
 78                         {
 79                             var instance = givenObject[i].ToString();  // Your custom conversion to string.
 80                             list.Add((T)(object)instance);
 81                         }
 82                         else
 83                         {
 84                             list.Add((T)(object)null);
 85                         }
 86                     }
 87                 }
 88             }
 89             else if (typeof(T).IsClass)
 90             {
 91                 foreach (DataRow item in dt.Rows)
 92                 {
 93                     T s = Activator.CreateInstance<T>();
 94                     for (int i = 0; i < dt.Columns.Count; i++)
 95                     {
 96                         PropertyInfo info = plist.Find(p => p.Name.ToUpper() == dt.Columns[i].ColumnName.ToUpper());
 97                         if (info != null)
 98                         {
 99                             try
100                             {
101                                 if (!Convert.IsDBNull(item[i]))
102                                 {
103                                     object v = null;
104                                     if (info.PropertyType.ToString().Contains("System.Nullable"))
105                                     {
106                                         v = Convert.ChangeType(item[i], Nullable.GetUnderlyingType(info.PropertyType));
107                                     }
108                                     else
109                                     {
110                                         if (info.PropertyType.BaseType != null && info.PropertyType.BaseType.ToString().Contains("System.Enum"))
111                                         {
112                                             //将字符串转换为枚举对象
113                                             //v = Enum.Parse(info.PropertyType, item[i].ToString());
114                                             v = int.Parse(item[i].ToString());
115                                         }
116                                         else
117                                         {
118                                             v = Convert.ChangeType(item[i], info.PropertyType);
119                                         }
120                                     }
121                                     info.SetValue(s, v, null);
122                                 }
123                             }
124                             catch (Exception ex)
125                             {
126                                 throw new Exception("字段[" + info.Name + "]转换出错," + ex.Message);
127                             }
128                         }
129                     }
130                     list.Add(s);
131                 }
132             }
133             else if (typeof(T).BaseType == typeof(System.ValueType))
134             {
135                 try
136                 {
137                     foreach (DataRow item in dt.Rows)
138                     {
139                         for (int i = 0; i < dt.Columns.Count; i++)
140                         {
141                             if (item[i] != DBNull.Value && item[i] != null)
142                             {
143                                 if (plist.Count > 0)
144                                 {
145                                     list.Add((T)((object)Convert.ChangeType(item[i], plist.LastOrDefault()?.PropertyType)));
146                                 }
147                                 else
148                                 {
149                                     if (item[i].GetType().ToString() == "System.Int64" && typeof(T).FullName == "System.Int32")
150                                     {
151                                         list.Add((T)((object)int.Parse(item[i].ToString())));
152                                     }
153                                     else
154                                     {
155                                         list.Add((T)((object)item[i]));
156                                     }
157                                 }
158                             }
159                             else
160                             {
161                                 list.Add((T)(object)null);
162                             }
163                         }
164                     }
165                 }
166                 catch (Exception ex)
167                 {
168                     throw new Exception("类型[" + typeof(T) + "]转换出错," + ex.Message);
169                 }
170             }
171             return list;
172         }
173 
174     }