list转datatble

public static DataTable ToDataTable<T>(this IEnumerable<T> varlist)
{
DataTable dtReturn = new DataTable();

// column names
PropertyInfo[] oProps = null;

if (varlist == null) return dtReturn;

foreach (T rec in varlist)
{
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;
}