【代码】C#将DataTable转为实体及实体模型

2021-12-28 10:24:10  阅读 90 次 评论 0 条

就是方便了操作,更直观的反映获得的实体

直接上代码

 public static class DataTableToEntityExtension
    {
        public static List<T> ToEntityList<T>(this DataTable dt) where T : class,new()
        {
            if (dt == null || dt.Rows.Count == 0) return new List<T>();

            List<T> entityList = new List<T>();

            Type entityType = typeof(T);
            PropertyInfo[] propertys = entityType.GetProperties();
            DataMappingAttribute mappingAttribute = null;
            object value = null;

            foreach (DataRow dr in dt.Rows)
            {
                T tEntity = new T();

                foreach (PropertyInfo pi in propertys)
                {
                    if (!pi.CanWrite) continue;

                    //pi.
                    var mattr = pi.GetCustomAttributes(typeof(DataMappingAttribute), false);
                    //mappingAttribute = (DataMappingAttribute)pi.GetCustomAttributes(false)[0];
                    if (mattr.Count() > 0)
                    {
                        mappingAttribute = mattr[0] as DataMappingAttribute;
                    }

                    if (mappingAttribute == null)
                    {
                        if (dt.Columns.Contains(pi.Name))
                        {
                            value = dr[pi.Name];
                        }
                        else
                        {
                            if (pi.PropertyType == typeof(decimal)
                                || pi.PropertyType == typeof(int)
                                || pi.PropertyType == typeof(double)
                                || pi.PropertyType == typeof(float))
                            {
                                value = 0;
                            }
                            else
                            {
                                value = null;
                            }
                        }
                    }
                    else if (mappingAttribute != null && dt.Columns.Contains(mappingAttribute.mappingName))
                    {
                        value = dr[mappingAttribute.mappingName];
                    }

                    if (value != DBNull.Value)
                    {
                        pi.SetValue(tEntity, value, null);
                    }
                }
                entityList.Add(tEntity);
            }
            return entityList;
        }
        public static T ToEntity<T>(this DataTable dt) where T : class,new()
        {
            if (dt == null || dt.Rows.Count == 0) return new T();



            Type entityType = typeof(T);
            PropertyInfo[] propertys = entityType.GetProperties();
            DataMappingAttribute mappingAttribute = null;
            object value = null;
            DataRow dr = dt.Rows[0];

            T tEntity = new T();

            foreach (PropertyInfo pi in propertys)
            {
                if (!pi.CanWrite) continue;

                //pi.
                var mattr = pi.GetCustomAttributes(typeof(DataMappingAttribute), false);
                //mappingAttribute = (DataMappingAttribute)pi.GetCustomAttributes(false)[0];
                if (mattr.Count() > 0)
                {
                    mappingAttribute = mattr[0] as DataMappingAttribute;
                }

                if (mappingAttribute == null)
                {
                    if (dt.Columns.Contains(pi.Name))
                    {
                        value = dr[pi.Name];
                    }
                    else
                    {
                        if (pi.PropertyType == typeof(decimal)
                            || pi.PropertyType == typeof(int)
                            || pi.PropertyType == typeof(double)
                            || pi.PropertyType == typeof(float))
                        {
                            value = 0;
                        }
                        else
                        {
                            value = null;
                        }
                    }
                }
                else if (mappingAttribute != null && dt.Columns.Contains(mappingAttribute.mappingName))
                {
                    value = dr[mappingAttribute.mappingName];
                }

                if (value != DBNull.Value)
                {
                    pi.SetValue(tEntity, value, null);
                }
            }


            return tEntity;
        }
    }

    [AttributeUsage(AttributeTargets.Property)]
    public class DataMappingAttribute : Attribute
    {
        public string mappingName;
        public DbType dbType;
        public DataMappingAttribute()
        { }

        public DataMappingAttribute(string mappingName, DbType dbType)
        {
            this.mappingName = mappingName;
            this.dbType = dbType;
        }
    }

使用:

List<UserInfo> userList = dataTable.ToEntityList<UserInfo>();
UserInfo user = dataTable.ToEntity<UserInfo>();



微信扫码查看本文
本文地址:https://www.yangguangdream.com/?id=2190
版权声明:本文为原创文章,版权归 编辑君 所有,欢迎分享本文,转载请保留出处!

发表评论


表情

还没有留言,还不快点抢沙发?