I use material icons. This way:
1 - I’ve inserted the .ttf file with the material icons in my assets:
2 - In the blocks I created a global variable to receive the icon:
3 - When receiving data to fill my ListViewCustom, I insert the icon for each record.
In this case it is inside a FOR…EACH loop.
4 - At the end of loop, I set the data and the icons to the listview:
And that’s it!!
Hope this helps.