The UN Trade and Development (UNCTAD) World Investment Report 2018 Country Fact Sheet for Africa contains useful information on the state of foreign direct investment (FDI) to/from Africa.
There was a significant drop in Africa, especially in southern Africa, of inward FDI from $53 billion in 2016 to $42 billion in 2017. There was a slight increase in outward FDI from $11 billion in 2016 to $12 billion in 2017.
The UNCTAD report also contains fact sheets for individual countries.