The 'await' operator can only be used within an async lambda expression error

Question

I have this function:

    public async Task<IEnumerable<RegionBreif>> GetAsync()
    {

    return await Table.Where(x => x.SiteId == _siteId).Select(r => new RegionBreif
    {
        IsServiceable = await RegionBreif.checkIfServicable(Context, r.SiteId, r.Id)
    }).ToArrayAsync();
}

And this function:

public static async Task<bool?> checkIfServicable(DbContext context, int? _siteId, int _regionId)
{
    var t = (from ir in context.Set<InspectionReview>()
             join so in context.Set<SiteObject>() on ir.ObjectId equals so.Id
             where so.SiteRegionId == _regionId && so.SiteId == _siteId
             select (bool?)
             ir.IsNormal);

    return t.Count() == 0 ? (bool?)null : t.Any(x => x.Value == false) ? false : true;
}

On this row:

await RegionBreif.checkIfServicable(Context, r.SiteId, r.Id)

I get this error:

Error 13 The 'await' operator can only be used within an async lambda expression. Consider marking this lambda expression with the 'async' modifier.

Answer 1

The problem is in the lambda expression you pass to the Select . If you want to make use of the await inside the type create, RegionBreif , you have to pass an async lambda expression as below:

Select(async r => new RegionBreif
{
    IsServiceable = await RegionBreif.checkIfServicable(Context, r.SiteId, r.Id)
})