https://docs.unity3d.com/ScriptReference/Experimental.AssetImporters.ScriptedImporter.html
I add a custom asset importer, according the sample code in the above manual.
I got the error blow
sometimes, i can get the right content.
And the asset,
ctx.AddObjectToAsset(“main obj”, asset);
ctx.SetMainObject(asset);
after enter once Editor PlayMode, the mainObject i loaded, is not my added asset anymore.
I need reimport it again.
Unity 2018.3.6f1