我如何更改 CSVHelper 中的字段顺序和字段名称

Question

我正在开发一个 asp.net mvc 4 Web 应用程序 + 实体框架 5.0，我有以下方法调用一个名为 AdvanceSearchStoredProcedure 的函数，该函数将调用一个存储过程：-

     public IQueryable<AdvanceSearchSP_Result> AdvanceSearch(NetworkAdvanceSearch na)
      {

        var r = entities.AdvanceSearchStoredProcedure("network",na.AssetTypeID,
        na.ip, na.ipselection, na.mac, na.macselection);
        return r.AsQueryable();           

      }

然后我从我的操作方法中调用此方法如下：-

public ActionResult AdvanceSearchIndexExport(AdvanceSearchSP_Result2 ns)

        {
            var result = WriteCsvToMemory(repository.AdvanceSearch(ns.NetwotkAS).ToList());
            var memoryStream = new MemoryStream(result);
            return new FileStreamResult(memoryStream, "text/csv") { FileDownloadName = "export.csv" };
        }
public byte[] WriteCsvToMemory(IEnumerable<AdvanceSearchSP_Result> records)
      {
          using (var memoryStream = new MemoryStream())
          using (var streamWriter = new StreamWriter(memoryStream))
          using (var csvWriter = new CsvWriter(streamWriter))
          {
              csvWriter.WriteRecords(records);
              streamWriter.Flush();
              return memoryStream.ToArray();
          }
      }

这是我的AdvanceSearchSP_Result 及其 MetadataType 类的部分类：-

[MetadataType(typeof(AdvanceSearchSP_Result_Validation))]

    public partial class AdvanceSearchSP_Result
    {


    }
public class AdvanceSearchSP_Result_Validation{
        [Display(Name="Service Tag")]
        public string SERVICETAG { get; set; }
         [Display(Name = "Serial Number")]
        public string SERIALNO { get; set; }
        [Display(Name = "Resource Tag")]
         public string Tag { get; set; }
        [Display(Name = "Resource Name")]
         public string RESOURCENAME { get; set; }
        [Display(Name = "State")]
         public string StateName { get; set; }
        [Display(Name = "Type")]
         public string TypeName { get; set; }
        [Display(Name = "Site Name")]
         public string sitename { get; set; }
        [Display(Name = "Customer Name")]
         public string cusotmername { get; set; }
         public bool ismanaged { get; set; }
}

现在我在生成的.CSV 文件中面临这些问题：-

1. 字段标题将与数据库中的列名相同，而不是在AdvanceSearchSP_Result_Validation MetadataType 类中定义。

2. 第二个问题，我不确定如何更改列的顺序？目前，订单将与存储过程中定义的一样。例如，我如何强制 ismanaged 成为 .csv 文件中的第一列？

我正在使用 CSVHelper https://www.nuget.org/packages/CsvHelper/ 库来执行实际的 CSV 导出。

编辑 现在我添加了这个类：-

public sealed class SPMap : ClassMap<AdvanceSearchSP_Result>
    {
        public SPMap()
    {
        Map(m => m.Tag).Name("Resource Tag").Index(0);
        Map(m => m.RESOURCENAME).Name("Asset Name").Index(1);
        Map(m => m.cusotmername).Name("Customer Name").Index(2);
        Map(m => m.sitename).Name("Site Name").Index(3);
        Map(m => m.StateName).Name("Asset State").Index(4);
        Map(m => m.ismanaged).Name("ismanaged").Index(5);
        Map(m => m.TypeName).Name("Technology Type ").Index(6);
        Map(m => m.SERVICETAG).Name("Service Tag").Index(7);
        Map(m => m.SERIALNO).Name("Serial Number").Index(8);

    }
    }

然后我修改我的方法以包含如下配置：-

 public byte[] WriteCsvToMemory(IEnumerable<AdvanceSearchSP_Result> records)
      {
          using (var memoryStream = new MemoryStream())
          using (var streamWriter = new StreamWriter(memoryStream))
          using (var csvWriter = new CsvWriter(streamWriter))
          {
              csvWriter.WriteRecords(records);
              csvWriter.Configuration.RegisterClassMap<SPMap>();
              streamWriter.Flush();
              return memoryStream.ToArray();
          }
      }

但我仍然得到了旧名称和旧顺序..所以public sealed class SPMap : ClassMap<AdvanceSearchSP_Result> 似乎没有任何效果......

Answer 1

我认为您需要一张地图来指定列的名称和索引：

public sealed class SPMap : ClassMap<AdvanceSearchSP_Result>
{
    public SPMap()
    {
        Map(m => m.SERVICETAG).Name("Service Tag").Index(0);
        Map(m => m.sitename).Name("Site Name").Index(1);
        /*repeat for other properties */
        ..
        .. 
    }
}

那你需要注册这个：

csvWriter.Configuration.RegisterClassMap<SPMap>();

我相信这会奏效。

见： http://joshclose.github.io/CsvHelper/mapping

Answer 2

public byte[] WriteItem<T>(List<T> collection) where T : class
        {


            Type t = typeof(T);
            string newLine = Environment.NewLine;

            object obj = Activator.CreateInstance(t);
            PropertyInfo[] props = obj.GetType().GetProperties();
            byte[] carriageReturnBytes = System.Text.Encoding.UTF8.GetBytes("\r");

            string text;
            using (MemoryStream ms = new MemoryStream())
            using (StreamReader sr = new StreamReader(ms))
            {
                foreach (PropertyInfo pi in props)
                {
                    byte[] data = System.Text.Encoding.UTF8.GetBytes(pi.Name.ToString() + ",");
                    ms.Write(data, 0, data.Length);
                }

                ms.Write(carriageReturnBytes, 0, carriageReturnBytes.Length);

                foreach (T item in collection)
                {
                    foreach (PropertyInfo pi in props)
                    {
                        string write =
                           Convert.ToString(item.GetType().GetProperty(pi.Name).GetValue(item, null)).Replace(",", " ") + ',';

                        byte[] data = System.Text.Encoding.UTF8.GetBytes(write);
                        ms.Write(data, 0, data.Length);
                    }

                    byte[] writeNewLine = System.Text.Encoding.UTF8.GetBytes(Environment.NewLine);
                    ms.Write(writeNewLine, 0, writeNewLine.Length);
                }

                ms.Position = 0;
                text = sr.ReadToEnd();
                return ms.ToArray();
            }
        }