如何通过代码“约定”使用映射忽略属性的映射

时间:2011-10-20 01:17:58

标签: c# nhibernate nhibernate-mapping

有没有办法通过代码约定使用映射来避免使用NHibernate 3.2映射属性?默认情况下,映射所有属性。

3 个答案:

答案 0 :(得分:2)

据我所知,有两种选择:

1)扩展ConventionModelMapper和SimpleModelInspector以扩展IsPersistentProperty,使其满足您的需求。

2)使用IsPersistentProperty如下:

...
mapper.IsPersistentProperty((memberInfo, declared) => IsPersistentProperty(mapper.ModelInspector, memberInfo, declared, "YourPropertyName"));
...


public static bool IsPersistentProperty(IModelInspector modelInspector, MemberInfo member, bool declared, string propertyName)
{
    return (declared ||(member is PropertyInfo) && !IsReadOnlyProperty(member)) && !member.Name.Equals(propertyName);
}

private static bool IsReadOnlyProperty(MemberInfo subject)
{
    const BindingFlags defaultBinding = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.DeclaredOnly;

    var property = subject as PropertyInfo;
    if (property == null)
    {
        return false;
    }
    if (CanReadCantWriteInsideType(property) || CanReadCantWriteInBaseType(property))
    {
        return !PropertyToField.DefaultStrategies.Values.Any(s => subject.DeclaringType.GetField(s.GetFieldName(property.Name), defaultBinding) != null) || IsAutoproperty(property);
    }
    return false;
}

private static bool IsAutoproperty(PropertyInfo property)
{
    return property.ReflectedType.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance
                                                                             | BindingFlags.DeclaredOnly).Any(pi => pi.Name == string.Concat("<", property.Name, ">k__BackingField"));
}

private static bool CanReadCantWriteInsideType(PropertyInfo property)
{
    return !property.CanWrite && property.CanRead && property.DeclaringType == property.ReflectedType;
}

private static bool CanReadCantWriteInBaseType(PropertyInfo property)
{
    if (property.DeclaringType == property.ReflectedType)
    {
        return false;
    }
    var rfprop = property.DeclaringType.GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance
                                                                             | BindingFlags.DeclaredOnly).SingleOrDefault(pi => pi.Name == property.Name);
    return rfprop != null && !rfprop.CanWrite && rfprop.CanRead;
}

答案 1 :(得分:2)

2)作为复制和粘贴IsPersistentProperty默认实现的替代方法,它可以通过反射重用:

var mapper = new ConventionModelMapper();
var field = mapper.ModelInspector.GetType()
    .GetField( "isPersistentProperty", BindingFlags.NonPublic | BindingFlags.Instance );

var ispp = (Func<MemberInfo, bool, bool>)field.GetValue( mapper.ModelInspector );
mapper.IsPersistentProperty( ( mi, b ) => ispp( mi, b ) 
   && ( /*any conditions here*/ mi.Name != "SomeFiledName" ) );

条件可以移动到单独的方法或类。基于表达式的stronly类型包装器可以在它上面完成。

答案 2 :(得分:1)

重复:Ignore column using mapping by code in HNibernate

您可以使用以下内容:

mapper.IsPersistentProperty((mi, declared) =>
                                             {
                                                 if (mi.DeclaringType == typeof (YourType) && mi.Name == "PropertyNameToIgnore")
                                                     return false;
                                                 return true;
                                             });