如何GetType().具有自定义属性的GetFields？

Question

这个旧代码返回一个使用反射在方法调用中使用属性修饰的字段列表

有没有办法用TypeDescripter或LINQ替换它？

    public static FieldInfo[] GetFieldsWithAttribute(Type type, Attribute attr, bool onlyFromType)
    {
        System.Reflection.FieldInfo[] infos = type.GetFields();
        int cnt = 0;
        foreach (System.Reflection.FieldInfo info in infos)
        {
            if (info.GetCustomAttributes(attr.GetType(), false).Length > 0)
            {
                if (onlyFromType && info.DeclaringType != type)
                    continue;

                cnt++;
            }
        }

        System.Reflection.FieldInfo[] rc = new System.Reflection.FieldInfo[cnt];
        // now reset !
        cnt = 0;

        foreach (System.Reflection.FieldInfo info in infos)
        {
            if (info.GetCustomAttributes(attr.GetType(), false).Length > 0)
            {
                if (onlyFromType && info.DeclaringType != type)
                    continue;

                rc[cnt++] = info;
            }
        }

        return rc;
    }

Answer 1

public static FieldInfo[] GetFieldsWithAttribute(Type type, Attribute attr, bool onlyFromType)
{
    System.Reflection.FieldInfo[] infos = type.GetFields();
    var selection = 
       infos.Where(info =>
         (info.GetCustomAttributes(attr.GetType(), false).Length > 0) &&
         ((!onlyFromType) || (info.DeclaringType == type)));

    return selection.ToArray();
}

如果您可以返回IEnumerable<FieldInfo>，您应该能够直接返回选择。