C# InvalidOperationException: Unable to resolve service for type 'AutoMapper.Mapper'

報錯信息：

InvalidOperationException: Unable to resolve service for type 'AutoMapper.Mapper'

while attempting to activate 'BLL.Implementation.Report'.

檢查后發現名稱寫錯了

錯誤：

private readonly Mapper _mapper;

正確的是：

private readonly IMapper _mapper;

總結

出現這類錯誤注意檢查接口與實現類名稱

 

另外一種情況是沒有在startup類的ConfigureServices中注入automapper依賴