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  • IEnumerable<T> 转换 DataTable

    Sample I:

    I created a public method called LINQToDataTable as following:

    public DataTable LINQToDataTable<T>(IEnumerable<T> varlist)
    {
         DataTable dtReturn = new DataTable();

         // column names 
         PropertyInfo[] oProps = null;

         if (varlist == null) return dtReturn;

         foreach (T rec in varlist)
         {
              // Use reflection to get property names, to create table, Only first time, others 
              will follow 
              if (oProps == null)
              {
                   oProps = ((
    Type)rec.GetType()).GetProperties();
                   foreach (PropertyInfo pi in oProps)
                   {
                        Type colType = pi.PropertyType;

                        if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition()      
                        ==typeof(Nullable<>)))
                         {
                             colType = colType.GetGenericArguments()[0];
                         }

                        dtReturn.Columns.Add(
    new DataColumn(pi.Name, colType));
                   }
              }

              DataRow dr = dtReturn.NewRow();

              foreach (PropertyInfo pi in oProps)
              {
                   dr[pi.Name] = pi.GetValue(rec,
    null) == null ?DBNull.Value :pi.GetValue
                   (rec,null);
              }

              dtReturn.Rows.Add(dr);
         }
         return dtReturn;
    }

    ---------------------------------------------------------------

    Example: To use this method, just use the following code sample:

    ---------------------------------------------------------------

    var vrCountry = from country in objEmpDataContext.CountryMaster
                            select new {country.CountryID,country.CountryName};

    DataTable dt = LINQToDataTable(vrCountry);

    Sample II

    Here is my second method:

    public DataTable ToDataTable(System.Data.Linq.DataContext ctx, object query)
    {
         if (query == null)
         {
              throw new ArgumentNullException("query");
         }
         
        
    IDbCommand
    cmd = ctx.GetCommand(query as IQueryable);
         SqlDataAdapter adapter = new SqlDataAdapter();
         adapter.SelectCommand = (
    SqlCommand)cmd;
         DataTable dt = new DataTable("sd");

         try
         {
              cmd.Connection.Open();
              adapter.FillSchema(dt,
    SchemaType.Source); 
              adapter.Fill(dt);
         }
         finally
         {
              cmd.Connection.Close();
         }
         return dt;
    }

    ---------------------------------------------------------------

    Example: To use this method, just use the following code sample:

    ---------------------------------------------------------------

    var vrCountry = from country in objEmpDataContext.CountryMaster
                            select new {country.CountryID,country.CountryName};

    DataTable dt = LINQToDataTable(objEmpDataContext,vrCountry);

     

    摘自:http://www.c-sharpcorner.com/UploadFile/VIMAL.LAKHERA/LINQResultsetToDatatable06242008042629AM/LINQResultsetToDatatable.aspx

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  • 原文地址:https://www.cnblogs.com/haoliansheng/p/1772308.html
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