How to instance type of configuration

13 Oct 2006 4:25 PM

Enosh Chang

Hi all:

I saw there is one line on configuration file as following,

    <add name="MyProfileProvider"
              connectionStringName="MyDatabase"
              applicationName="/"
              type="System.Web.Profile.SqlProfileProvider, System.Web" />

I want to know how to instance type in my code. Thanks!

Best Regards
Enosh Chang

13 Oct 2006 4:33 PM

Carl Daniel [VC++ MVP]

"Enosh Chang" <changen***@yahoo.com.tw> wrote in message
news:%23Q1bvQu7GHA.3644@TK2MSFTNGP03.phx.gbl...
> Hi all:
>
> I saw there is one line on configuration file as following,
>
>    <add name="MyProfileProvider"
>              connectionStringName="MyDatabase"
>              applicationName="/"
>              type="System.Web.Profile.SqlProfileProvider, System.Web" />
>
> I want to know how to instance type in my code. Thanks!

I think you're asking how to create an instance of a type knowing only the
name of the type. In that case:

Type ty = Type.GetType(
    "System.Web.Profile.SqlProfileProvider, System.Web"
    );
System.Web.SqlProfileProvider prov
    = (System.Web.SqlProfileProvider)Activator.CreateInstance(ty);

If that wasn't what you were looking for, post back with a more detailed
question.

-cd

13 Oct 2006 4:41 PM

Massimo

Show quote

"Carl Daniel [VC++ MVP]" <cpdaniel_remove_this_and_nospam@mvps.org.nospam>
ha scritto nel messaggio news:uHXRJVu7GHA.4500@TK2MSFTNGP02.phx.gbl...

>> I saw there is one line on configuration file as following,
>>
>>    <add name="MyProfileProvider"
>>              connectionStringName="MyDatabase"
>>              applicationName="/"
>>              type="System.Web.Profile.SqlProfileProvider, System.Web" />
>>
>> I want to know how to instance type in my code. Thanks!
>
> I think you're asking how to create an instance of a type knowing only the
> name of the type. In that case:
>
> Type ty = Type.GetType(
>    "System.Web.Profile.SqlProfileProvider, System.Web"
>    );
> System.Web.SqlProfileProvider prov
>    = (System.Web.SqlProfileProvider)Activator.CreateInstance(ty);

You probably should use an interface or an abstract class here: if you're
reading the type name from a configuration file, chanches are you just don't
know the actual type of the object, so you can't give a type to "prov".

Massimo

13 Oct 2006 11:26 PM

Enosh Chang

"Massimo" <bar***@mclink.it>

???????:%23LFqsZu7GHA.4***@TK2MSFTNGP05.phx.gbl...
Show quote

> "Carl Daniel [VC++ MVP]" <cpdaniel_remove_this_and_nospam@mvps.org.nospam>
> ha scritto nel messaggio news:uHXRJVu7GHA.4500@TK2MSFTNGP02.phx.gbl...
>
>>> I saw there is one line on configuration file as following,
>>>
>>>    <add name="MyProfileProvider"
>>>              connectionStringName="MyDatabase"
>>>              applicationName="/"
>>>              type="System.Web.Profile.SqlProfileProvider, System.Web" />
>>>
>>> I want to know how to instance type in my code. Thanks!
>>
>> I think you're asking how to create an instance of a type knowing only
>> the name of the type. In that case:
>>
>> Type ty = Type.GetType(
>>    "System.Web.Profile.SqlProfileProvider, System.Web"
>>    );
>> System.Web.SqlProfileProvider prov
>>    = (System.Web.SqlProfileProvider)Activator.CreateInstance(ty);
>
> You probably should use an interface or an abstract class here: if you're
> reading the type name from a configuration file, chanches are you just
> don't know the actual type of the object, so you can't give a type to
> "prov".
>
>
> Massimo
>

That's so great. But I encounter another problem that it displays "Could not
load file or assembly 'XXXXX' or one of its dependencies" for some types.
How to solve this problem, dynamic loading assemblies?