所以我有同样的miff......我不能说我已经对我的解决方案进行了基准测试,但它似乎运行得相当快......
3位:
public static T Transform<T>(this object convertFrom) where T : class, new()
{
return (T) (new ServiceExtension().Transform(convertFrom, typeof (T)));
}
private class ServiceExtension
{
public object Transform(object convertFrom, Type convertTo)
{
object _t = Activator.CreateInstance(convertTo);
if (convertFrom == null) return _t;
var convertType = convertFrom.GetType();
foreach (
var property in _t.GetType().GetProperties().Where(f => f.CanWrite && f.GetSetMethod(true).IsPublic)
)
{
if (property.GetCustomAttributes(typeof (TransformAttribute), true).Any())
{
var transform =
(property.GetCustomAttributes(typeof (TransformAttribute), true).FirstOrDefault() as
TransformAttribute);
var transformname = transform.RelatedField ?? property.Name;
if (convertType.GetProperty(transformname) == null)
throw new ArgumentException(
string.Format(
"We were unable to find property:\"{0}\" on {1}. Please check the RelativeField value on the {2} for \"{0}\"",
transformname, convertFrom.GetType().Name, convertTo.Name));
var theValue = convertType.GetProperty(transformname).GetValue(convertFrom);
if (isCollection(theValue))
{
foreach (var item in (theValue as ICollection))
{
var someVal = new object();
var newToType = property.PropertyType.GetGenericArguments().FirstOrDefault();
if (!String.IsNullOrEmpty(transform.FullyQualifiedName))
someVal =
Transform(
item.GetType().GetProperty(transform.FullyQualifiedName).GetValue(item),
newToType);
else
someVal = Transform(item, newToType);
if (property.GetValue(_t) == null)
throw new NullReferenceException(
string.Format(
"The following property:{0} is null on {1}. Likely this needs to be initialized inside of {1}'s empty constructor",
property.Name, _t.GetType().Name));
property.PropertyType.GetMethod("Add")
.Invoke(property.GetValue(_t), new[] {someVal});
//property.SetValue(_t, theValue.Transform(theValue.GetType()));
}
}
else
property.SetValue(_t, theValue);
}
//property.SetValue(_t, property.GetValue(convertFrom, null), null);
}
return _t;
}
public bool isCollection(object o)
{
return o is ICollection
|| typeof (ICollection<>).IsInstanceOfType(o);
}
}
public class TransformAttribute : Attribute
{
public string RelatedField { get; private set; }
public string FullyQualifiedName { get; set; }
public TransformAttribute()
{
}
public TransformAttribute(string relatedField)
{
RelatedField = relatedField;
}
}
这样最终结果是:myObject.Transform()
但是这些装饰可以让你解释你的 POCO 和你的 ViewModel 之间的差异