只有在我的代码中显式访问属性时，才能通过反射访问任务属性

Question

I'm trying to access a property of a Task in an MS Project via System.Type.GetProperty("Finish") , but it looks like the property (and others like it eg Number1 ) is not accessible via reflection unless my code specifically uses that property. Is this a compiler setting that I can change? I'm writing a synchronization engine so it is impossible to tell ahead of time what field of a Task the client system may request.

So with the example below info will be null.

System.Type ty = typeof(Task);
System.Reflection.PropertyInfo info = ty.GetProperty("Finish");

but with the code below info is returned as a valid PropertyInfo object.

Task tk = activeProject.ProjectSummaryTask;
object done = tk.Finish;
System.Type ty = typeof(Task);
System.Reflection.PropertyInfo info = ty.GetProperty("Finish");

I basically expected GetProperty() to work for all the properties listed in the API for Task (which are quite a few).

Here is a link to the API for the Finish property: https://docs.microsoft.com/en-us/dotnet/api/microsoft.office.interop.msproject.task.finish?view=office-project-server

Answer 1

Use the GetField method of the Task object to return the value for a variable field.

You'll need to identify the field by the internal field ID--use the intrinsic constant (eg pjTaskFinish) or its numerical value (188743716).

Alternatively, you can convert friendly field names to constants using the FieldNameToFieldConstant method of the Application object.

ps the VBA-version of the documentation contains more information; most, if not all, objects/methods/properties are the same.