Dynamically instantiate class and call function

[Christian Havel]

Hi,

can I create a instance from a class which is another assembly and call a
function inside this assembly? I know the assembly name, class name, the
function name and its signature.

Thanks
Christian

[Vladimir Matveev]

Re: Dynamically instantiate class and call function

yes, you can

Assembly otherAssembly = Assembly.Load(. ..);

Type type = otherAssemby.Ge tType(typename) ;

object obj = otherAssembly.C reateInstance(t ype);

BindingFlags bf = BindingFlags.In vokeMethod | BindingFlags.In stance |
BindingFlags.Pu blic | BindingFlags.No nPublic;

type.InvokeMemb er("methodname" , bf, null, obj, new object[] {arg1,
arg2});

// or
ISomeWellKnownI nterface ifc =
(ISomeWellKnown Interface)other Assembly.Create Instance(typena me);
ifc.methodname( arg1, arg2);

[Marc Gravell]

Re: Dynamically instantiate class and call function

Something like this?

Assembly a = Assembly.LoadWi thPartialName(" MyAssembly");
object obj = a.CreateInstanc e("MyType");
Type[] signature = new Type[] {typeof(int), typeof(string)} ;
MethodInfo method = obj.GetType().G etMethod("MyMet hod",
signature);
object[] parameters = new object[] { 123, "abc" };
method.Invoke(o bj, parameters);

Note: if you can, I would advise working against an interface, i.e. make
both MyAssembly and the above code reference a (single) separate assembly
with IMyInterface {void MyMethod(int value1, string value2);} - you can then
just case obj to IMyInterface and you don't need anywhere near as much
reflection.

Marc

[Christian Havel]

Re: Dynamically instantiate class and call function

Hi Vladimir,

thanks for your help.

Bye Christian

"Vladimir Matveev" schrieb:
[color=blue]
> yes, you can
>
> Assembly otherAssembly = Assembly.Load(. ..);
>
> Type type = otherAssemby.Ge tType(typename) ;
>
> object obj = otherAssembly.C reateInstance(t ype);
>
> BindingFlags bf = BindingFlags.In vokeMethod | BindingFlags.In stance |
> BindingFlags.Pu blic | BindingFlags.No nPublic;
>
> type.InvokeMemb er("methodname" , bf, null, obj, new object[] {arg1,
> arg2});
>
> // or
> ISomeWellKnownI nterface ifc =
> (ISomeWellKnown Interface)other Assembly.Create Instance(typena me);
> ifc.methodname( arg1, arg2);
>
>[/color]

[Christian Havel]

Re: Dynamically instantiate class and call function

Hi Marc,

thanks for your help and regards from Munich.

Christian

"Marc Gravell" schrieb:
[color=blue]
> Something like this?
>
> Assembly a = Assembly.LoadWi thPartialName(" MyAssembly");
> object obj = a.CreateInstanc e("MyType");
> Type[] signature = new Type[] {typeof(int), typeof(string)} ;
> MethodInfo method = obj.GetType().G etMethod("MyMet hod",
> signature);
> object[] parameters = new object[] { 123, "abc" };
> method.Invoke(o bj, parameters);
>
> Note: if you can, I would advise working against an interface, i.e. make
> both MyAssembly and the above code reference a (single) separate assembly
> with IMyInterface {void MyMethod(int value1, string value2);} - you can then
> just case obj to IMyInterface and you don't need anywhere near as much
> reflection.
>
> Marc
>
>
>[/color]

[Christian Havel]

Re: Dynamically instantiate class and call function

Hi,

it works! But how can I solve this problem if the assembly is located not in
the GAC but in the application directory?

Thanks
Christian

"Vladimir Matveev" schrieb:
[color=blue]
> yes, you can
>
> Assembly otherAssembly = Assembly.Load(. ..);
>
> Type type = otherAssemby.Ge tType(typename) ;
>
> object obj = otherAssembly.C reateInstance(t ype);
>
> BindingFlags bf = BindingFlags.In vokeMethod | BindingFlags.In stance |
> BindingFlags.Pu blic | BindingFlags.No nPublic;
>
> type.InvokeMemb er("methodname" , bf, null, obj, new object[] {arg1,
> arg2});
>
> // or
> ISomeWellKnownI nterface ifc =
> (ISomeWellKnown Interface)other Assembly.Create Instance(typena me);
> ifc.methodname( arg1, arg2);
>
>[/color]

[Vladimir Matveev]

Re: Dynamically instantiate class and call function

You also can subscribe to AppDomain.Assem blyResolve event and locate it
manually

[Ignacio Machin \( .NET/ C# MVP \)]

Re: Dynamically instantiate class and call function

Hi,

"Christian Havel" <ChristianHavel @discussions.mi crosoft.com> wrote in
message news:A47054B3-E805-4B44-8076-0B8674545210@mi crosoft.com...[color=blue]
> Hi,
>
> it works! But how can I solve this problem if the assembly is located not
> in
> the GAC but in the application directory?[/color]

Assembly.LoadFr om will do it


--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

[Christian Havel]

Re: Dynamically instantiate class and call function

Hi Vladimir,

thanks a lot.
Christian

"Vladimir Matveev" schrieb:
[color=blue]
> You also can subscribe to AppDomain.Assem blyResolve event and locate it
> manually
>
>[/color]

[Christian Havel]

Re: Dynamically instantiate class and call function

Hi Ignacio,

thanks a lot and regards from Munich.

Christian

"Ignacio Machin ( .NET/ C# MVP )" schrieb:
[color=blue]
> Hi,
>
> "Christian Havel" <ChristianHavel @discussions.mi crosoft.com> wrote in
> message news:A47054B3-E805-4B44-8076-0B8674545210@mi crosoft.com...[color=green]
> > Hi,
> >
> > it works! But how can I solve this problem if the assembly is located not
> > in
> > the GAC but in the application directory?[/color]
>
> Assembly.LoadFr om will do it
>
>
> --
> Ignacio Machin,
> ignacio.machin AT dot.state.fl.us
> Florida Department Of Transportation
>
>
>[/color]