How can turn datatable into dictionary ?

Question

I am using Visual Studio 2017.

 

I want to convert datatable into dictionary, so that I can iterate over the testid key. The datable has 8 columns. 

 

So after converting I should be able to iterrate over it as shown below

 

string testy=dbDict(Testid).ColumnName.toString();

 

Thank you for the answer;