UIControlledApplicationLoadAddIn Method

Loads add-ins from the given manifest file.

Namespace: Autodesk.Revit.UI
Assembly: RevitAPIUI (in RevitAPIUI.dll) Version: 25.0.0.0 (25.0.0.0)
Syntax
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public void LoadAddIn(
	string fileName
)

Parameters

fileName  String
The name of the add-in manifest file including the extension is to identify the manifest file which contains Revit add-ins.
Exceptions
ExceptionCondition
FileArgumentNotFoundExceptionThrown when manifest file which is specified by fileName doesn't exist.
ArgumentNullExceptionThrown if the fileName is null or empty.
ArgumentExceptionThrown if the fileName doesn't end with 'addin'.
ApplicationExceptionThrown if the manifest file can't be parsed successfully.
InvalidOperationExceptionThrown when any of the newly added external applications fails to load and/or initialize properly, possibly because of one of the following reasons: AllowLoadingIntoExistingSession property is 'No'.Client id is duplicated.External application start up failed.
Remarks

This method loads the add-ins listed in the provided add-in manifest file. The API will look for the file in the dedicated folders supported by Revit for loading add-in manifest files.

Some add-ins may have settings in which they decline the ability for Revit to load the external application declared in the .addin in mid-session. This happens when the AllowLoadingIntoExistingSession tag is set to "No" in the add-in manifest file, and if the tag isn't present, the default is set to "Yes".

Note that when Revit starts an add-in in the middle of the session, some add-in logic may not function as expected because of the different interactions with the session. Specifically:

  • If the application's goal is to prevent something from happening, the application may not be able to handle the fact that this activity has already happened in the existing session.
  • If the application's goal is to manage external information in synch with documents loaded in the session, the application may not be able to handle documents that were loaded before the application started.
If the application's logic depends on the ApplicationInitialized event, this event has already been called before the add-in was loaded.

Also, some add-ins may not be able to fully initialize when loading in the middle of the session. This is because some activities must take place at the start of the Revit session:

  • Creation of custom failure definitions
  • Establishment of a system-wide IFailureProcessor to handle all failures.
  • Registering ExternalServices.

See Also