DRH

To remove this error check your code manually if every thing in the code you write is okay…

if your code is okay check the .csproj file…
write the following code if not present..
<ItemGroup>    <Folder Include=”wwwroot\”/>  </ItemGroup>

after again write migration command:
go to (project manager console) PM> dotnet ef migrations add YourMigrationName

If still not solved look at:https://stackoverflow.com/questions/44785540/ef-core-add-migration-build-failed/47775946

1. Use of Cross Platform For Building Application:
   As the Heterogeniety of system increases.Many Cross platforms are arises so that same code and same platform works to devices likes ios, android.Some of most popular Platform to make cross platfrom app are:
   i. Flutter
   ii. React Native
   iii. Xamerian
   iv. Phone Gap
2. Focus on UI/UX: In these days developer more focusing on the User experience and user interface,so that customer likes to visit the sites again and again.
3. artificial Intelligence: It is first according to the market but because of not sufficient data for the analysis and resaerch I put this in fourth position but it will soon switch to top.
4. Block Chain:  It , is a growing list of records, called blocks, they are linked together using cryptography. Every block is related to neighboring block means each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree ) This is the application of cryptographic application.
5. IoT(Internet of things): This is also the emerging topic of the world today every thing is digitizing so IoT plays major role.
6. Digital marketing: Digital marketing means to make listing sites in top postion by search engine,It is current trend, This is also called search engine optimization