/// <summary>
/// 从reader读取数据并映射到类型type的类这里要求Type必须有一个默认的无参构造函数并且返回指定类型的集合
/// </summary>
/// <param name="type">要映射的类型</param>
/// <param name="convertType">要转换到的类型</param>
/// <param name="reader">IdataReader</param>
/// <returns>IEnumerable</returns>
public static IEnumerable ToEnumerable(Type type, Type convertType, IDataReader reader)
{
var list = System.Activator.CreateInstance(typeof(List <>).MakeGenericType(convertType)) as IList;
var binding = ModelBindingHelper.GetBinding(type, reader, string.Empty);
using (reader)
{
while (reader.Read())
{
var obj = ActivatorHelper.CreateInstance(type);
var o = binding.Bind(obj);
if (Cac.ContainsKey(type.FullName + convertType.FullName))
{
var co = Cac[type.FullName + convertType.FullName];
list.Add(co(obj));
}
else
{
var paramobj = Expression.Parameter(typeof(object), "obj");
var covert = Expression.Convert(paramobj, convertType);
var lambda = Expression.Lambda <Func <object, object> >(covert, paramobj);
var co = lambda.Compile();
Cac.Add(type.FullName + convertType.FullName, co);
list.Add(co(obj));
}
}
}
return(list);
}
public static object ToModel(Type type, IDataReader reader, string prefix = "")
{
using (reader)
{
if (reader.Read())
{
var obj = ActivatorHelper.CreateInstance(type);
return(BindModel(obj, reader, prefix));
}
}
return(null);
}
/// <summary>
/// 从reader读取数据并映射到类型type的类这里要求Type必须有一个默认的无参构造函数
/// 也可以是Type可是是如List(Student) 这种类型 但是Student类型必须是有无参构造函数的类
/// </summary>
/// <param name="type">要映射的类型System.Type</param>
/// <param name="reader">IDataReader</param>
/// <param name="prefix"></param>
/// <returns>IEnumerable</returns>
public static IEnumerable ToEnumerable(Type type, IDataReader reader, string prefix = "")
{
IList list = null;
Type modelType = null;
bool isArry = false;
//直接接收泛型类型
if (type.IsGenericType && typeof(IList).IsAssignableFrom(type))
{
list = ActivatorHelper.CreateInstance(type) as IList;
modelType = type.GetGenericArguments()[0];
}
else if (typeof(Array).IsAssignableFrom(type))
{
isArry = true;
modelType = type.GetElementType();
}
else
{
list = ActivatorHelper.CreateInstance(typeof(List <>).MakeGenericType(type)) as IList;
modelType = type;
}
var binding = ModelBindingHelper.GetBinding(modelType, reader, string.Empty);
binding.Prefix = prefix;
using (reader)
{
while (reader.Read())
{
var obj = ActivatorHelper.CreateInstance(modelType);
var o = binding.Bind(obj);
list.Add(o);
}
}
return(list);
}
