Seems FontThumbnailService isn't fully working on Azure AppService

[jonascarlbaum]

Same code works differently locally and in cloud (Azure AppService). Some thumbs won't load in Azure, everyone works locally. Same ttf-file locally and on Azure.

Used like this, won't work on Azure:

[ThumbnailIcon("fa-light-300.ttf", 0xf015)]

Used like this, works on Azure:

[ThumbnailIcon("fa-light-300.ttf", 0xf1ea)]

Error:

Parameter is not valid. at System.Drawing.Bitmap..ctor(String filename)

Seems like some icons works to generate thumbnails from, and some won't.

Some files seems to be zero sized too.

---

It seems like new Bitmap(path) won't work reliably in Cloud see here and here since .

Error exists in FontThumbnailService.cs.

Proposed fix might be changing this, if new Bitmap works best with stream instead of path:

if (File.Exists(cachePath))
{
    using (var bmpTemp = new Bitmap(cachePath))
    {
       return new Bitmap(bmpTemp);
    }
}

to this (dummy-coded):

if (File.Exists(cachePath))
{
    using (StreamReader sr = new StreamReader(cachePath)) 
    {
        using (var bmpTemp = new Bitmap(sr))
        {
            return new Bitmap(bmpTemp);
        }
    }
}

[jonascarlbaum]

Clearing cached thumbnails didn't work.
But I managed to solve it by clearing the cached thumbnails and restart Azure AppService.

So that's an interesting behaviour. ;)

[degborta]

Yeah, that's strange.. I'll give it a look and see if I can reproduce it.

[jonascarlbaum]

@degborta Seems like same behaviour occurs over time on local machine too — can check error logs the next time it happens. It happened after adding new thumbnails and Re-compiled. IIS-reset after clearing thumbs works locally too as a ”fix”.