Reflection Newbie - More detailed problem description

[Ron M. Newman]

Hi,

what I really want is XML Persistence - the writing side is DONE, what I'm
working on is the reading. I am storing dynamic attributed objects. an
attributed object is a collection of named attributes and their values.

for example:

attribute name: "name"
attribute type: "System.String"
attribute value: "Mr. Smith"

attribute name "age"
attribute type: "Sytstem.Int32"
attribute value: "32"

my question is, once I have loaded the attribute description from XML and I
have the type and value, I'd like to re-create the object in memory and
assign th evalue to it. not everything supports Parse, so I might have to
decide that those objects that do not have "Parse" would use serialization
in writing and reading. Also, I know you can't just instantiate "String()"
it doesn't have an empty constructor prototype.

I guess what I need now is an advice on how you'd solve this problem. Is
there a golden rule I can use here? or am I doomed to make a private case
for Strings, things that have "Parse" and objects like images which must be
serialized.

Thanks
Ron

 

[Eric Cadwell]

Have you looked at XMLSerializer? Why recreate the wheel?

If you must, it would go something like...

string obj = "Person";

string prop = "Age";

string typ = "System.Int32";

string val = "12";

object o = Activator.CreateInstance(Type.GetType(obj));

object b = val;

Type t = Type.GetType(typ);

PropertyInfo pi = o.GetType().GetProperty(prop, t);

if (pi != null)

{

if (t.IsAssignableFrom(typeof(int)))

b = int.Parse(val);

pi.SetValue(o, b, null);

}

 

[Ron M. Newman]

Hi,

my data structures are very complex, lots of hashings and things that
XMLSerializer just cannot deal with automatically, plus, I don't need all
the information in the data structures and some of it is C# framework and I
can't just go there and change the XML directives ([XML......]) to match
what I need. So it seems like I have no choice but to "re-invent" the wheel
or flatten my world before writing, reading it flat, and un-flattening it
for re-use.

How do I create a String object as part of an automated process that has no
special cases when the only thing I have is "System.String" as a type? This
class doesn't have a default constructor.

Ron

 

[Dave Sexton]

Hi Ron,

How do I create a String object as part of an automated process that has no special cases when the only thing I have is
"System.String" as a type? This class doesn't have a default constructor.

If your pulling the value from an XML file then it's already a string. So if you encounter "System.String", then do nothing.

--
Dave Sexton

Hi,

my data structures are very complex, lots of hashings and things that XMLSerializer just cannot deal with automatically, plus, I
don't need all the information in the data structures and some of it is C# framework and I can't just go there and change the XML
directives ([XML......]) to match what I need. So it seems like I have no choice but to "re-invent" the wheel or flatten my world
before writing, reading it flat, and un-flattening it for re-use.

How do I create a String object as part of an automated process that has no special cases when the only thing I have is
"System.String" as a type? This class doesn't have a default constructor.

Ron

Have you looked at XMLSerializer? Why recreate the wheel?

If you must, it would go something like...

string obj = "Person";

string prop = "Age";

string typ = "System.Int32";

string val = "12";

object o = Activator.CreateInstance(Type.GetType(obj));

object b = val;

Type t = Type.GetType(typ);

PropertyInfo pi = o.GetType().GetProperty(prop, t);

if (pi != null)

{

if (t.IsAssignableFrom(typeof(int)))

b = int.Parse(val);

pi.SetValue(o, b, null);

}