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What happens if class is not available?

I have "MyProject.Commons.frmMessageBox"

if I wanna create it, doing this,

using (MyProject.Commons.frmMessageBox xFrm = new
MyProject.Commons.frmMessageBox())
{
xFrm.ShowDialog();
}

if I do not know "MyProject.Commons.frmMessageBox" is available or not and
want to handle this situation like this

if (Available("MyProject.Commons.frmMessageBox"))
{
ShowCustomDialog("MyProject.Commons.frmMessageBox" );
}

This is possible ?
Jul 30 '08 #1
5 1090
Why would it not be available? If it not referenced by your project, you will
get a compiler error and visual studio, you will get a compiler warning.
--
Ciaran O''Donnell
http://wannabedeveloper.spaces.live.com
"Diego Armando Maradona" wrote:
I have "MyProject.Commons.frmMessageBox"

if I wanna create it, doing this,

using (MyProject.Commons.frmMessageBox xFrm = new
MyProject.Commons.frmMessageBox())
{
xFrm.ShowDialog();
}

if I do not know "MyProject.Commons.frmMessageBox" is available or not and
want to handle this situation like this

if (Available("MyProject.Commons.frmMessageBox"))
{
ShowCustomDialog("MyProject.Commons.frmMessageBox" );
}

This is possible ?
Jul 30 '08 #2
Yes, you could probably do something funky with reflection and exception
handling to do this. However I agree with the above poster, if you're trying
to do this you've probably made an incorrect design decision somewhere else.

"Diego Armando Maradona" wrote:
I have "MyProject.Commons.frmMessageBox"

if I wanna create it, doing this,

using (MyProject.Commons.frmMessageBox xFrm = new
MyProject.Commons.frmMessageBox())
{
xFrm.ShowDialog();
}

if I do not know "MyProject.Commons.frmMessageBox" is available or not and
want to handle this situation like this

if (Available("MyProject.Commons.frmMessageBox"))
{
ShowCustomDialog("MyProject.Commons.frmMessageBox" );
}

This is possible ?
Jul 30 '08 #3
Ciaran O''Donnell wrote:
Why would it not be available? If it not referenced by your project, you will
get a compiler error and visual studio, you will get a compiler warning.
An assembly containing the referenced class could be replaced later (at
runtime) - just guessing: maybe .NET will display an 'Open File' Dialog
in this case and friendly ask the user to locate a file which contains
the class "MyProject.Commons.frmMessageBox" ...

Error messages are so medieval ;-)

Best Regards
--
Michael Justin
SCJP, SCJA
betasoft - Software for Delphi™ and for the Java™ platform
http://www.mikejustin.com - http://www.betabeans.de
Jul 30 '08 #4
The runtime will through an error if the assembly containing the type has
been replaced with a version that doesnt contain it. There is sadly no nice
OpenFileDialog.
--
Ciaran O''Donnell
http://wannabedeveloper.spaces.live.com
"Michael Justin" wrote:
Ciaran O''Donnell wrote:
Why would it not be available? If it not referenced by your project, you will
get a compiler error and visual studio, you will get a compiler warning.

An assembly containing the referenced class could be replaced later (at
runtime) - just guessing: maybe .NET will display an 'Open File' Dialog
in this case and friendly ask the user to locate a file which contains
the class "MyProject.Commons.frmMessageBox" ...

Error messages are so medieval ;-)

Best Regards
--
Michael Justin
SCJP, SCJA
betasoft - Software for Delphi™ and for the Java™ platform
http://www.mikejustin.com - http://www.betabeans.de
Jul 30 '08 #5
Diego Armando Maradona wrote:
I have "MyProject.Commons.frmMessageBox"

if I wanna create it, doing this,

using (MyProject.Commons.frmMessageBox xFrm = new
MyProject.Commons.frmMessageBox())
{
xFrm.ShowDialog();
}

if I do not know "MyProject.Commons.frmMessageBox" is available or not
and want to handle this situation like this

if (Available("MyProject.Commons.frmMessageBox"))
{
ShowCustomDialog("MyProject.Commons.frmMessageBox" );
}

This is possible ?
I think what you want in this case is a plugin architecture with a
default fallback that just shows a normal messagebox.
You would have to load the assembly dynamically if it exists.
Google c# plugin and you should see how you could do it.

JB
Aug 1 '08 #6

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