I need to create a COM object on server.
In VB you can do this: (tutorial)
xlApp = CreateObject("Excel.Application", "\\MyServer")
But how to do same thing on C#?
I know how to do it locally:
var infsrv = new InfoServ.TInfoServerClass();
But don't know how to do it on server..
There's nothing wrong with adding a reference to Microsoft.VisualBasic so that you can simply use the same method. This is very much a nicety of .NET, it would be a waste not to use it. It is however simple to do, just two lines of code:
public static object CreateObject(string progid, string server) {
var t = Type.GetTypeFromProgID(progid, server, true);
return Activator.CreateInstance(t);
}
Well, one line if you push it. In this specific case you definitely should consider adding a reference to Microsoft.Office.Interop.Excel. You can then simply use the new operator, get speedier code because you are not late-binding and get IntelliSense. If you want to stick with late binding then be sure to use the C# version 4 support for the dynamic keyword. Writing late bound code in earlier C# versions is quite painful.
Unable to cast COM object of type 'System.__ComObject' to class type 'InfoServ.TInfoServerClass'. COM components that enter the CLR and do not support IProvideClassInfo or that do not have any interop assembly registered will be wrapped in the __ComObject type. Instances of this type cannot be cast to any other class; however they can be cast to interfaces as long as the underlying COM component supports QueryInterface calls for the IID of the interface.InfoServ.TInfoServerClass infsrv = (InfoServ.TInfoServerClass)Activator.CreateInstance(myType);
You can add a reference to the Microsoft.VisualBasic.dll to your C# project and use CreateObject directly. This might be the easiest solution if you have an existing codebase that uses a lot of VB.NET specific features:
using Microsoft.VisualBasic;
...
dynamic xlApp = Interaction.CreateObject("Excel.Application", "MyServer");
Note: Since the backslash is a special character in C#, either remove the \\ from the server name (see above) or escape the string @"\\MyServer".
Use this overload of Type.GetTypeFromCLSID.
