/// <summary>
/// 映射数据源中的数据到目标对象
/// </summary>
/// <typeparam name="TDestination"></typeparam>
/// <param name="source"></param>
/// <returns></returns>
public static List <TDestination> List <TDestination>(object source)
{
var accessor = GetAccessor <TDestination>();
if (accessor == null)
{
throw new MapperException(string.Format("未找到适用{0}的对象访问器。", typeof(TDestination).FullName));
}
var typeMapper = NativeTypeMapper.GetTypeMapper <TDestination>();
var dataSourceReader = NativeDataSourceReader.GetReader(source);
var fields = accessor.MetaInfo.GetPropertyNames();
dataSourceReader.Ordinal(fields);
var list = new List <TDestination>(dataSourceReader.Count > 0 ? dataSourceReader.Count : 8);
object[] initData;
while (null != (initData = dataSourceReader.Read()))
{
TDestination destObj = typeMapper.Cast(initData);
if (destObj != null)
{
list.Add(destObj);
}
}
return(list);
}
/// <summary>
/// 获取IMapper<<typeparamref name="T"/>>
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
public static IObjectAccessor <T> GetAccessor <T>()
{
var typeMapper = NativeTypeMapper.GetTypeMapper <T>() as ObjectTypeMapper <T>;
if (typeMapper != null)
{
return(typeMapper.ObjAccessor);
}
return(default(IObjectAccessor <T>));
}
/// <summary>
///
/// </summary>
/// <param name="field"></param>
public PropertyAccessor(PropertyInfo propertyInfo)
{
_typeMapper = NativeTypeMapper.GetTypeMapper(propertyInfo.PropertyType);
var param1 = Expression.Parameter(typeof(T), "handler");
var param2 = Expression.Parameter(typeof(object), "value");
// 获取属性的值的方法
var accessExp = Expression.MakeUnary(ExpressionType.Convert, Expression.MakeMemberAccess(param1, propertyInfo), typeof(object));
_getter = Expression.Lambda <Func <T, object> >(accessExp, param1).Compile();
// 向属性赋值的方法
var assignExp = Expression.Assign(
Expression.Property(param1, propertyInfo),
Expression.Call(Expression.Convert(Expression.Constant(_typeMapper), typeof(ITypeMapper <>).MakeGenericType(propertyInfo.PropertyType)), "Cast", new Type[0], new ParameterExpression[] { param2 })
);
_setter = Expression.Lambda <Action <T, object> >(assignExp, param1, param2).Compile();
}
/// <summary>
/// 映射数据源中的一行数据到目标对象
/// </summary>
/// <typeparam name="TDestination"></typeparam>
/// <param name="source"></param>
/// <returns></returns>
public static TDestination Single <TDestination>(object source)
{
var accessor = GetAccessor <TDestination>();
if (accessor == null)
{
throw new MapperException(string.Format("未找到适用{0}的对象访问器。", typeof(TDestination).FullName));
}
var dataSourceReader = NativeDataSourceReader.GetReader(source);
var fields = accessor.MetaInfo.GetPropertyNames();
dataSourceReader.Ordinal(fields);
var initData = dataSourceReader.Read();
if (initData != null)
{
return(NativeTypeMapper.GetTypeMapper <TDestination>().Cast(initData));
}
return(default(TDestination));
}
