[Bug]: SmartButton icons set via __selfinit__ do not update during reload in C# launcher

[Wurschdhaud]

✈ Pre-Flight checks

• I don't have SentinelOne antivirus installed (see above for the solution)
• I have searched in the issues (open and closed) but couldn't find a similar issue
• I have searched in the pyRevit Forum for similar issues
• I already followed the installation troubleshooting guide thoroughly
• I am using the latest pyRevit Version

🐞 Describe the bug

When a SmartButton's selfinit script changes the button icon using set_icon(), the icon change does not persist after a pyRevit reload. The button reverts to the icon that was parsed from disk during the initial load.

Example being the update button: after updating, the button remains orange instead of resetting.

⌨ Error/Debug Message

update button doesn't clear its orange color after updating (which triggers reloading)

♻️ To Reproduce

No response

⏲️ Expected behavior

Root Cause:

The C# loader's IconManager maintains a BitmapCache for loaded bitmap sources 1 . While the ExtensionParser clears its _iconCache during reload via ClearAllCaches() 2 , the IconManager's BitmapCache is never cleared. The ClearCache() method exists 3 but is not called in the reload sequence.

Reload Flow:

1. ExtensionParser.ClearAllCaches() clears the icon file path cache
2. Icons are re-parsed from disk and applied via IconManager.ApplyIcon() 4
3. SmartButton __selfinit__ runs and may call set_icon() to override the icon 5
4. On next reload, step 2 re-applies the cached bitmap from the BitmapCache, overriding the __selfinit__ changes

Comparison with Python Loader:

The legacy Python loader does not have this issue because it creates new bitmaps on every set_icon() call without a persistent cache 6 . The ButtonIcons class reads the file and creates bitmaps fresh each time 7 .

Suggested Fix:

Call IconManager.ClearCache() during the reload sequence to ensure bitmaps are reloaded from disk, similar to how the ExtensionParser clears its icon path cache.

Notes

The issue is specific to the C# loader path. The Python loader's icon handling in uimaker.py and ribbon.py does not use a persistent bitmap cache, so SmartButton icon changes via __selfinit__ work correctly in the legacy loader.

🖥️ Hardware and Software Setup (please complete the following information)

latest

Additional context

No response