private List <T> ToList(DbDataReader reader, EntityDescription description)
{
List <T> list = new List <T>(Initializer.Instance.DefaultEntityListLen);
string[] names = DataExtensions.GetColumnNames(reader);
while (reader.Read())
{
T instance = GetSingle(reader, description, names);
list.Add(instance);
}
return(list);
}
public T ToSingle(DbDataReader reader)
{
if (reader.Read())
{
EntityDescription description = EntityDescriptionCache.Get(typeof(T));
string[] names = DataExtensions.GetColumnNames(reader);
return(GetSingle(reader, description, names));
}
else
{
return(default(T));
}
}
/// <summary>
/// 供实体加载器使用的内部方法，请不要在代码中调用！
/// </summary>
/// <param name="dataSource"></param>
/// <param name="len"></param>
/// <param name="kvs"></param>
/// <returns></returns>
public static int[] CreateNameMapIndex(object dataSource, int len, params KeyValuePair <int, string>[] kvs)
{
string[] names = null;
DbDataReader reader = dataSource as DbDataReader;
if (reader != null)
{
names = DataExtensions.GetColumnNames(reader);
}
else
{
names = DataExtensions.GetColumnNames((DataTable)dataSource);
}
// 优化这段代码的性能 （性能提升 60%）
//int[] colIndex = new int[19];
//colIndex[0] = DataExtensions.FindIndex(names, "rid");
//colIndex[1] = DataExtensions.FindIndex(names, "intA");
//colIndex[2] = DataExtensions.FindIndex(names, "timeA");
//colIndex[3] = DataExtensions.FindIndex(names, "moneyA");
// ............................
int[] colIndex = new int[len];
foreach (var kv in kvs)
{
int index = -1;
for (int i = 0; i < names.Length; i++)
{
if (names[i] != null &&
string.Compare(names[i], kv.Value, StringComparison.OrdinalIgnoreCase) == 0)
{
index = i;
names[i] = null; // 节省后续查找时间
break;
}
}
colIndex[kv.Key] = index;
}
return(colIndex);
}