c# Api 错误 Unable to resolve service for type ' ' while attempting to activate ' '

.net8 中提示 以上错误
增加了 

 builder.Services.AddScoped<IFlowCoefficient, FlowCoefficientManageService>();   仍无效 提示错误

改为    builder.Services.AddScoped(typeof(FlowCoefficientManageService));